Contents

Cover

Title Page

Warhammer 40,000

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Chapter 10

Chapter 11

Chapter 12

Chapter 13

Chapter 14

Chapter 15

Epilogue

About the Author

A Black Library Publication

Warhammer 40,000

It is the 41st millennium. For more than a hundred centuries the Emperor has sat immobile on the Golden Throne of Earth. He is the Master of Mankind by the will of the gods, and master of a million worlds by the might of His inexhaustible armies. He is a rotting carcass writhing invisibly with power from the Dark Age of Technology. He is the Carrion Lord of the Imperium for whom a thousand souls are sacrificed every day, so that He may never truly die.

Yet even in His deathless state, the Emperor continues His eternal vigilance. Mighty battlefleets cross the daemon-infested miasma of the warp, the only route between distant stars, their way lit by the Astronomican, the psychic manifestation of the Emperor’s will. Vast armies give battle in His name on uncounted worlds. Greatest amongst His soldiers are the Adeptus Astartes, the Space Marines, bio-engineered super-warriors. Their comrades in arms are legion: the Astra Militarum and countless planetary defence forces, the ever-vigilant Inquisition and the tech-priests of the Adeptus Mechanicus to name only a few. But for all their multitudes, they are barely enough to hold off the ever-present threat from aliens, heretics, mutants – and worse.

To be a man in such times is to be one amongst untold billions. It is to live in the cruellest and most bloody regime imaginable. These are the tales of those times. Forget the power of technology and science, for so much has been forgotten, never to be re-learned. Forget the promise of progress and understanding, for in the grim dark future there is only war. There is no peace amongst the stars, only an eternity of carnage and slaughter, and the laughter of thirsting gods.

From the pinnacle of Az Khalak’s immense citadel, Koshao could see as far as the Demetrian Plains and beyond the silvery line of the Laskaih River. All that she surveyed was a scene of destruction. The city that nestled around the great fortress was almost untouched – here and there a district had been flattened by long-range missiles of opportunistic orbital fire. Further out, there was barely a hectare of mountainside or flatland not marked by shell crater, wreck or corpse.

The streams that fed the Laskaih ran red with blood seeping from the battle dead. Woodlands had been burned to dunes of ash. The sky itself was stained with the smoke of burning tanks and transports.

Even now the shadow of another army spread across the river like a pall of filth.

‘Hundreds of thousands dead, and still they persist,’ she said, glancing to her companion. She pulled her cloak tighter about her, the cold wind tousling greying hair. ‘The Servants of the False Light will never cease in their attempts to silence the truth.’

The man beside her – her husband of seventy-two years, as judged on Nicomedua – shrugged. ‘The truth does not care for our travails.’

He extended a segmented artificial limb and laid it about her shoulders, pulling her closer. She felt the familiar jag of his other augmentations pressing against her flesh from beneath his black robe – a robe that had been red in deference to Mars until three years ago.

‘The longer we prevail, the greater the power of the truth we uncover.’ He waved a pincer-clawed hand across the scene of devastation. ‘They ruin themselves in a quest for ignorance.’

A bright flash drew their eyes upwards. The sky was dimming to evening, and several glints of dying light were reflected in the heavens. Drop-ships.

It was not long before the city’s block-sized landers could clearly be seen, seven of them, followed by an uncountable swarm of smaller craft.

‘They are larger than those that came before,’ remarked Koshao.

‘Titans,’ said Longmyar. ‘The Machine-God finally sends the engines of death.’

‘Titans…’ whispered Koshao, cowed by the thought of the war machines descending towards Nicomedua. A steady stream of dropcraft fell towards the planet, bringing a battle force whose entire purpose was to break cities and conquer worlds. Long plasma jets shone brighter than the setting suns as they prepared to touch down beside the river.

She shuddered.

‘Do not fret, Koshao.’ Longmyar smiled. ‘The Tangential Path shall set us all free.’

Chapter 1

The Casus Belli Goes To War

‘Almighty Machine-God whose data binds the universe, look upon your humble servant and let the tangents of your intersection be beneficent.’

As ve spoke the ritual lines, Magos Dominus Militaris Xaiozanus Skitara Xilliarkis Exasas dilated the dorsal spiracles of vis intertracular lymphoid to release a cloud of bacteriophagic incense. The vapour billowed as a purple cloud, cleansing the air of biological contaminants that might infect the implant connection points in the few remaining parts of vis flesh.

Vis sense of smell had been replaced by far more complex molecular sensors when vis face had been removed, yet vis sensory system still latched on to the old memories and interpreted the smell as forge exhaust and hot metal. It was an aroma that ve had known since vis first moments in the incense-sterilised hatcheries of Metalica.

Lifting up one of four multi-jointed gripping limbs, Exasas let three drops of blessed lubricant spill from the slender bottle in vis grip. Flexible optical lenses capable of microscopic vision tracked the trio of liquid spheres as they fell past the gantry on which Exasas stood with the other senior tech-priests of Casus Belli. Ve followed their fall for several metres until they hit the gilded crest of the Titan’s head below.

From this vantage point the Imperator continued down into the brightly illuminated main deck of the Legio Metalica landing barge. Arrayed about the feet-citadels of the Casus Belli were lines of white-clad skitarii waiting for the command to board, arranged by squad and platoon, the precision of their ranks pleasing to Exasas.

Ve extended a link through the noosphere that connected to the skitarii alphas far below. At vis invisible command the squad leaders became surrogates for vis physical presence, an extension of vis communication system. Even as ve framed the thoughts, the words were announced by the mouths of the dozen alphas, ringing from across the Titan dock.

‘Tech-guard of the Casus Belli, the perambulations of destiny have again brought us to holy war. Our great Imperator is to be unleashed against the heretek darkness that has befallen Nicomedua. The servants of the Omnissiah have turned from their duties and we shall be the punishment unleashed against them in the name of the Machine-God. The Legio Metalica are blessed to be chosen as the executioners of this sacred task. With our companion-engines we shall see Nicomedua delivered back to the light of diligent service.

‘I stand before you as magos dominus, incarnation of the martial precision of the Cult Metalica. We are one, indivisible, favoured in the working of the Machine-God, for we have been given this sacred duty and in its completion shall move closer to the perfection of the Omnissiah’s design.’

Another noospheric pulse sent the embarkation order into the alphas, who disseminated the command to their squads. In unison, the skitarii offered their weapons in salute and then turned towards the gates of the Imperator’s citadel-like lower legs.

‘I still do not comprehend why you insist upon this ceremony. One might as well expend energy boosting the morale of a circuit breaker.’

Recognising the voice of Zerkei Metalis Gevren, the dominus turned vis centipede-like body to face the moderatus prime. Along with the other moderati, Gevren approached along the docking gantry, passing from the light of the vast chamber into the shadow of the Casus Belli’s akropoliz carapace superstructure.

Unlike the magos and the other tech-priests, the moderatus prime and his companions mostly retained their human anatomy. It was partly in honour of the humanoid form of the Titan, and partly because when they interfaced with the Casus Belli’s mind impulse units it remained more natural for them if they shared the same number of limbs and basic shape. Even the hint of a phantom limb reaction could prove devastating when spiritually connected to a forty-metre-tall war engine.

They wore bulky piloting uniforms rather than robes, though in the same white as the Metalican tech-priests, and each carried their interface helm under their arm.

Gevren himself was a solid figure, broad at the waist and shoulder, with a similarly slab-like face and flat nose. The glitter of implants behind his eyes and a few stud-points in the sides of his neck indicated the presence of the mind impulse unit connections inserted into his flesh.

‘It is not as if your warriors will contribute anything meaningful to this battle,’ added Moderatus Secundus Haili. Her smile was one of patient contempt as the group stopped on the other side of the gantry line, leaving a path to the command module entry ramp. ‘We shall leave them only ruins to guard.’

‘There are some duties beyond even the wrath of the Casus Belli, Zerkei,’ argued Exasas. ‘Tasks that are beneath the dignity of an Imperator Titan, but nonetheless vital to victory. If the ruins need to be guarded, my skitarii will be equal to the challenge.’

‘They are simply martial lubrication, Xaiozanus,’ said Gevren. ‘Human grease for the gears of battle. It is a pity that you waste your intellect with such a dull subject.’

The last moderatus, Rasdia, said nothing, but his expression was one of condescension. The coterie of moderati fell silent at the approach of the princeps senioris. Like them, she did not wear the robes of office, but her single-piece protective suit was more elaborate, decorated with gilded piping and ruby-studded fasteners. Her face was lined with age – and the toll of melding with the psychometric circuits of the Casus Belli. Slender black lines beneath the skin of her neck and throat and in the backs of the hands that held the interface helm betrayed the presence of life-prolonging inserts. She walked with the aid of a cane fashioned from the bone of a Titan-sized tyranid beast they had destroyed on Durasa Four.

‘You are looking at my stick again, magos dominus,’ Princeps Senioris Iealona said. ‘Even with your five independent visual detectors, I can tell when you are looking at my cane.’

‘Your perception is infallible as ever, princeps senioris.’ Exasas constricted vis body segments to shorten verself, bringing vis theoretical eyeline to the same level as the princeps senioris’. ‘It seems an unnecessary peripheral assistance.’

‘And I must remind you again that I cannot risk my harmony with the Casus Belli with further changes to my physiology or chemical balances. So, I must limp.’

She stopped between the two groups, tech-priests of all shapes and sizes to the left, human moderati on her right. As with the Imperator itself, she was the fulcrum upon which the alliance turned, the mechanical and the organic fused within her when she interfaced with the Titan.

‘You wish to test Liberik’s Fourth Theorem during our engagement?’ she said, looking at Exasas.

‘I do,’ the magos replied. Ve caught Gevren shaking his head scornfully. ‘I have proposed a corollary that I wish to enact with my troops, if it is possible.’

‘I will see what can be done, but I think it unlikely there will be any infantry engagement today.’

Despite the life-extension surgeries and cerebral enhancements ve had undergone, the dominus was still capable of disappointment. Ve remained still, containing any display of the emotion before the princeps senioris.

‘I am your honoured servant, princeps senioris. We shall do as the Machine-God moves us.’

‘That we shall,’ said Iealona. She glanced at her moderati and waved her cane towards the zigzagging ramp that led into the open gate in the side of the Imperator’s head. ‘Time to get started. We are due to rendezvous with the rest of our battle group in forty-seven minutes and begin the assault in sixty. Six Warlords, three Reavers, three Warhounds and a pair of Warriors shall be accompanying us. And a whole skitarii support echelon. We shall not keep them waiting.’

They advanced as a group along the gantry. It made Exasas uncomfortable, seeing their individual stride patterns, making no effort to harmonise their movements. Their humanity was meant to be key to their success with the mind impulse unit, but to the magos it seemed like a terrible inefficiency.

Ve spurted an audible packet of binaric at the other tech-priests and together they followed the humans into the Casus Belli.

Each of them in turn briefly approached the small shrine alcove in the docking vestibule, laying a hand or tentacle-like mechadendrite on the twelve-toothed cog symbol rendered in gleaming platinum upon the devotional stand. Exasas placed the tip of a tendril against the symbol and felt a pulse of recognition from the Titan’s dormant spirit.

‘Benevolent Casus Belli, I commend my body to your protection and dedicate my mind to your service.’

An archway led to a corridor that descended into the command module proper, cleansing incense falling curtain-like across the opening. Exasas moved through, inhaling deeply of the strong fragrance, neuroreceptors firing swiftly under the influence of the stimulating agents contained within the mist.

‘Almighty Machine-God whose data binds the universe, look upon your humble servant and let the tangents of your intersection be beneficent.’

The callipers of Ghelsa’s augmetic phalanges clicked as her dark-skinned fingers closed around six meticulously inscribed steel polyhedrons. She lifted them from the polished offering plate and touched them to the breast of her off-white coverall.

Ghelsa kissed her steel-wrapped fist and held the shapes to her brow. Her metal-capped knuckles clinked against the silver twelve-toothed cog set into the flesh of her forehead before she threw her hand down.

Cast from her fingers, the twelve-sided dice clattered into the concave bowl, skittering around the raised lip. Shadows and light played over the spinning, skipping shapes as the silent watchers crowded closer, peering over Ghelsa’s and Adrina’s shoulders as they waited for the dice to come a halt.

The duluz of the downdecks wore a mixture of tabards, half-robes, kilts and coveralls depending on station and expertise. Many showed signs of crude augmentation – either gifted by a patron in the upper echelons of the priesthood or made in one of the basic workshops of the lower spaces. Like Ghelsa’s, their clothes were uniformly off-white, the colours of their hegemaarkhus, the forge world of Metalica. Their formal allegiance colours were augmented with an array of tattoos, piercings, brand marks and other decorations to identify home world, sect membership, personal relationships and other sundry information. Most had not seen the metal-sheathed planet, but were natives of various vassal systems or the detritus of conquest and liberation swept up by the Casus Belli on one of its many campaigns. Ghelsa was one such tributai, sent to serve in the Legio Metalica as part of an ancient pact between the tech-priests and her world of Zakhinta.

The gaming pieces belonged to Ghelsa, who was proud to tell anyone who asked that she had made them herself from bearings that had once been part of the Casus Belli’s starboard hip main rotator. She had salvaged them two years earlier during a rededication to the Machine-God and spent half of that time diligently filing the flat surfaces with a handrasp and autopolish. She had used an acid stylus to etch the twelve sacred symbols, each one of the Perfections of Form as listed in the holy books of Metalica.

A red flare of light played over the settled dodecahedrons – the signal beam from Adrina’s artificial left eye. Ghelsa was quicker to count the revealed symbols than her opponent’s scan-mechanism.

‘Four iambic crucibae,’ she groaned, throwing up her hands in despair.

‘Militus Martia!’ her opponent cried in triumph, reverting to crude Gothic in his excitement.

There was a mix of cheers and moans from the onlookers as various side bets were won and lost.

Adrina held out a pudgy, oil-stained hand, his smile not unkind. Half a tattoo was just visible where his wrist entered the tattered white cuff of his overseer’s robe, depicting the iron skull of the Legio icon. He was epilekhtoz, Metalican-born, hence his higher station.

He beckoned with fingers tipped with broken nails, their golden enamel chipped and scratched.

‘Hand it over, vin Jaint. Everyone saw you swear the wager before the Omnissiah’s oracular.’

She delved a hand into one of her coverall’s many pockets and produced a thin sliver of circuit-covered plastek. Adrina leered as he made to snatch it from her fingers. Ghelsa pulled it out of reach.

‘One downshift only,’ she warned, glancing to the others as witnesses. ‘And if you’re caught, you didn’t get it from me.’

Adrina nodded, his fingers twitching in excitement.

‘Come on, come on, my downshift starts soon.’

Eyes narrowed, Ghelsa handed over the forged datachip. The overseer thrust it into an inner pocket of his robe, hiked his chain of office more comfortably around his neck and gave a smile. He stood, head bent to one side to avoid the condensation-dappled coolant pipe that ran through the small chamber.

‘Always a pleasure, vin Jaint. Luckily for all of us you’re a better spindle-wrangler than you are a player of Omnissekh.’ The crowd parted to let Adrina pass and they filed away, ducking beneath the various cables, pipes and other impediments between them and the small hatch that led back into maintenance duct S-11.

Notasa lingered for a moment after the others had left, his gaze suggestive, which was impressive considering his eyes had been mirror-sheathed, the orbs like pure quicksilver.

‘You can’t win at everything, Ghelsa,’ said the diminutive duct-runner. He leaned back against the bulkhead, arching his neck like a contented feline. ‘But no need to be sad for long.’

‘The lower port manifold array is coming loose,’ Ghelsa said with a grimace of lost opportunity. ‘I really should go and fix it.’

‘Always so dutiful,’ snapped Notasa, his anger fuelled by rejection. He flicked stained blond hair from his face, revealing skin pocked with tiny scars from errant welder sparks. ‘You know they’ll never make you epilekhtoz, no matter how hard you work. You’ll always be tributai like the rest of us.’

‘You’ve got it all wrong, berth-friend,’ Ghelsa said, stepping forward. She picked up the metre-long multi-tool she had left beside the door. Its considerable weight was nothing in her grasp, her own significant musculature assisted by a tracery of exo-skeletal cable sealed into her flesh.

‘How about on the downshift?’ Ghelsa asked, feeling the urge to reconcile even though, rationally, she knew she had done nothing wrong.

‘Just go and fix that manifold array,’ muttered Notasa, stepping away from the hatch. ‘Maybe we’ll see each other later.’

Already anxious about the time she had spent playing Omnissekh, Ghelsa aimed a kiss towards Notasa’s cheek, but he retreated, scowling. The spindle-wrangler ducked out into the corridor, stepping out from the relative cool and quiet of the coolant exchange access.

The sound had always been there, of course, and most of the time Ghelsa barely registered it. For three and a half years – Martian-adjusted standard – she had lived on or around the Casus Belli. Since achieving adulthood her existence had been dedicated to the services of the Machine-God, as dictated and directed by the Adeptus Mechanicus.

Yet there were times, like now, when she moved from one part of the downdecks to another and listened again, her attention drawn back to the nuances of her home. There was the obvious noise, the clatter and clank, the grinding of the massive gears, the low pulsing of the reactor links. Any neophyte could identify them within a matter of days. It was the deeper, quieter sounds that were the most welcoming. The hiss of coolant as a spin-off drained heat down from the main reactor exchanges. The ever-present gurgle of waste water falling through the cisterns beneath the starboard decks. The thrum of the pumps inside the capillary towers that took lubricant up to the immense hellstorm cannon.

She stepped into a pass-niche as a trio of sweat-slicked mattokhai labourers dashed past, the uncoupled pieces of their thrum-hammer over their shoulders, power cables swishing like monkey tails. Droplets of perspiration trickled down her cheek and the side of her nose, the heat and humidity of the core-ways as oppressive as the first-hour labour-sermons of the tech-priests. Ghelsa made her way along the corridor, the metal dappled by the pale yellow glow of lumens behind wire cages, in places splashed by the green or amber of a system registry lamp through a grimy inspection plate.

Through the mechanical din she detected organic sounds. The hacking cough of Merkadoa, who was still waiting on a promised new lung after an incident with the trash conflagrator’s secondary exhaust. Chatter. Ceaseless, unintelligible sounds occasionally punctuated by a spurt of screeching, clicking binaric from a passing enginseer, and ever so occasionally the artificially modulated tones of a higher-ranking tech-priest descended from the God-decks to conduct an inspection or investigate a delayed report.

Just as her constitution had adapted to the clammy conditions, and her ears were attuned to the sonic flexes of the internal society of the downdecks, so her eyes were well accustomed to the gloom. With her other senses guiding her unconsciously to her destination, Ghelsa was free to wander almost at will, knowing instinctively where to step around open hatches, dodge across ladder holes and duck beneath intervening cables and piping. It was mid-shift and most of the others were at their stations, the narrow walkways and transit-bridges populated only by occasional movement.

Through the doors and arches she passed she saw other tributai at their work, blotches of white through clouds of vapour. She saw smears of paleness in dark maintenance bays or clustered around the fully robed enginseers as some fundamental duty was enacted or a Principle of Conduct passed on for the appeasement of an itinerant fragment of Casus Belli’s all-encompassing machine-spirit.

Thoughts fixed on her job in the lowest decks, Ghelsa moved on.

The command module dominated the inside of the Imperator Titan’s head. Two massive eye-like screens relayed realtime feeds from thousands of augurs across the war engine, creating a complex representation of the surroundings in both visual and noospheric frameworks. Exasas not only saw the doors of the barge’s hangar as a human would, but knew exactly the composition of the metal and the weight and torsion values, as well as a welter of data on atmospheric pressure, temperature and other tertiary readings. It was the closest ve could come to feeling as the Titan felt without the benefit of the mind impulse units to organically share the sensation.

The princeps senioris’ main command throne sat on a dais towards the back of the chamber, looking down at the three moderati positions. Each was a reclining chair beneath a tangle of cables that would connect to the incumbent’s MIU systems. On the left, Moderatus Haili controlled the energies of the plasma annihilator; the twinned position on the right for the hellstorm cannon was the seat of Moderatus Rasdia. The two of them made for their couches, handing their interface helms to the tech-priests attending each station.

Moderatus Gevren was stationed between them, responsible for the activation and monitoring of the rest of the Casus Belli’s considerable arsenal – main battery, defence laser, anti-aircraft systems and point defence weaponry.

In most Titans the moderati were in sole control of their armaments, but the guns of the Casus Belli were too large for a single moderatus to control – or in the case of Gevren, too numerous. They were aided by gunnery teams with the weapons themselves, mostly slaved servitors that acted as extensions of the moderatus’ will, each team overseen by a trio of tech-priests to ensure their continued operation.

Between the princeps senioris’ throne and the moderati, and along the outer walls of the chamber to either side, the tech-priests addressed their panels and interfaces. The noosphere crackled with their intent, linking their minds even as dataports and mechadendrites connected them physically with the Omnissiah’s greatest warrior.

Exasas’ position was just behind the moderatus prime, from which ve could link into the noosphere signals related to the skitarii systems and personnel. Connecting to the cogitators, ve felt the company of warriors settling into their barracks chambers within the two leg-citadels, and several more platoons likewise preparing for departure in the battle stations of the akropoliz.

Ve could feel the skitarii as a homogeneous force, or relay part of vis strategic consciousness into one of a hundred and forty-two separate organisms via their noospheric cortical weaves. In a split second the magos dominus could switch to the individual view of a particular warrior – ve picked one on a whim and watched the faces of the three soldiers opposite through vis chosen receptacle’s eyes. At the same time, cyclical simulators tracked other battle-pertinent datafeeds, for the moment semi-dormant and reliant on the last orbital data uploads ve had taken just before boarding.

Little had changed and the princeps senioris’ assessment that there was only a small probability of infantry engagement remained accurate. Their mission was to break the heretek lines defending a citadel and break into the mountain passes, spearheading the full battle group. It was an overwhelming use of force, mounted not only to sweep aside the barriers to the advances of the Astra Militarum and other skitarii armies, but also to demonstrate the folly of further resistance to the will of the Omnissiah.

Exasas played back vis memory-store of the prime dominus’ instruction, passing it through vis thoughts and into the minds of vis subordinates.

Exasas [broad trans/concept/loop]: <Az Khalak will burn by nightfall.>

A tremor ran through the noosphere, a throb of intent that channelled into every datafeed. Exasas turned one of vis sensory inputs to the princeps senioris and saw that she wore her helm, its MIU cables linking her to the essence of the behemoth she would guide into battle.

Sharing her thoughts, made whole by the metaphorical sacrifice of her consciousness, Casus Belli started to rise from its slumber. The leading edge of a powerful wave of awareness touched upon the noosphere and digital systems flickered into wakefulness, caressing Exasas’ sensory inputs. Ve heard a sigh from Iealona’s parted lips, grunts and murmurs emanating from the moderati as they were joined to the machine-spirit.

Exasas could not comprehend how it might feel to be one with the god-machine. Ve could interpret the millions of data-signals and extrapolate sensory curves for eternity and still not know what it was like to share physicality with the might of the Imperator. Only Iealona and her predecessors had shared that singular, glorious experience.

A visual feed highlighted a glint of amber light on the head of the bone cane leaning against the side of the command throne. While monitoring the other developments, Exasas allowed a portion of vis thoughts to consider the implications. Princeps senioris, and to a lesser extent moderati, had shortened lifespans due to their connections with the immortal spirits of the Titans. For the Machine-God’s warriors to live, their mortal components had to shed a little of their span. Even as her frail body was failing, the princeps senioris was able to clad her thoughts in the armour and power of the Imperator. She could not escape her mortality – in fact she hastened it – but in the time she had, she could share the body and thoughts of an immortal.

As an exchange, it was not without merit.

The noosphere flared with reports and counter-signals, confirming the readings of the plasma reactor, the online status of motivation and balance systems and the networking of the mind impulse units with the moderati and princeps senioris.

Exasas sent vis own confirmations, having spared a moment to check that all skitarii personnel were aboard and at their stations.

Awoken, the spirit of Casus Belli yearned to be free of the confines of the barge. With a final flurry of data exchanges, the tech-priests allowed the reactor to come to full power and the MIU to flow unhindered between the circuits of the Imperator and the synapses of its princeps senioris.

Casus Belli lived.

In semi-aware fashion, Ghelsa traversed the main lateral passages of the Imperator Titan’s downdecks, coming upon the third service shaft from the rear. The mechanism was nothing more than an old autoloader, repurposed by the engine crew for human cargo. Two shafts contained a continuously slow-moving chain, every few metre-long links interspersed with a metal platform just large enough for a foot.

Ghelsa waited at the drop-shaft until the next platform rattled into view and then quickly stepped out, bare foot on the plate, one arm wrapping through a chain link. The descent carried her past the wall of heat that emanated from the sealed reactor decks into the comparative gloom and cool of the motivator and traction assembly. So much quicker than negotiating the monkey-ladders.

She deftly jumped off at the main actuator array – a huge gearing system that powered the left hip joint of the forty-metre-tall war engine. Artificial fibre bundles each thicker than her waist vibrated with latent power while the hiss of immense pneumatics punctuated a steady grinding of metal on metal. The entire compartment shook, a constant tremor that pulsed through the nervous system. Just a few metres away, immense cog teeth that could crush her in moments knitted together, the piercing screech of their contact setting her teeth on edge.

She immediately saw the dysfunction, her experienced eye drawn to the ever-so-slight wobble of a tertiary drive shaft linking in to the main coupling. Here, close to the fulcrum of the hip’s movement, there was little sense of vertical motion compared to the upper downdecks or the heights of the templedecks. The floor rose and lowered laboriously like a ship on a lazy ocean swell. The turn of the gears was a far better indication of the Titan’s stride. At the moment it was at a comfortable cruising pace, perhaps four strides per minute, each step covering some fifteen metres of ground. They had been in motion for a while – since before the dice game had started – and she reckoned the landing barge was now several kilometres behind them.

There was a pause of three and a half seconds at the apogee of the stride during which cantilevers and secondary gyros compensated for the shift of weight from one system to the other. Ghelsa waited, bobbing lightly on the balls of her feet, adjusting the wrench head of the multi-tool to the required bite.

Just as the drop-gear shifted into place, some twenty metres below her the Titan’s massive foot settled into the ground. Ghelsa sprang into action. She pulled herself up onto the box of the main drive train and latched the head of the multi-tool around the errant fitting. Her exo-muscles creaked as she pulled back, one foot braced against a cross-stanchion. One turn. Two… The second pull seized at the halfway mark, fully tightened.

Ghelsa loosened the tool, pulled it free and jumped back to the deck with half a second to spare. She watched the drive system engage again, and listened for an erroneous clatter. The wheel spun smoothly, its low growl testament to a job completed.

‘The Machine-God blesses,’ she intoned, lifting the multi-tool to touch the godplate upon her brow. ‘In praise of the Omnissiah our duty is done.’

She cast her eye around for any other small fixes that might be performed while she was there, but all seemed to be running well. The tributai took a deep breath. The air was thick with lubricant and incense, a mix she had come to know and adore in her time aboard the Casus Belli. Those of different homes might long for the scent of fresh bread or the animals in their pens, but for Ghelsa it was the machine smells that made her feel safe.

By the rattle of the lifter chain she knew a platform was coming around. She stepped back into the alcove without looking, her foot coming upon the plate just as it passed the level of the floor.

Taken up once more, she wondered what other tasks awaited her and started to hum a slow inkanta in her contentment.

Two decks up, just below the reactor exchanges, movement and alien sound caught her attention. Through the grille of the deck above she saw a huddle of people wearing the red-lined cloaks of the hyperezia, the tech-priests’ enforcers in the downdecks. Their grunts and shouts were audible above the noise, and Ghelsa could clearly see fists and short staves rising and falling – they were beating someone.

She was not one to interfere in the disciplining of another, but that it took place here in the dark rather than before the peers of the offender struck her as odd. Ghelsa alighted on the deck a few metres away from the gaggle, noting the blood on their knuckles and mauls.

‘What’s happening here?’ she called out.

One of the hyperezia cast a glance over his shoulder, bearded face half shrouded in shadow.

‘Get gone, oil-rat,’ snarled the henchman.

In moving, he revealed something of the victim. Ghelsa glimpsed a blood-spattered hand and a white sleeve, but saw no mark upon the wrist.

‘Ho there, that’s a tributai!’ she shouted, taking another step.

‘He’s a heretek, is what he is,’ one of the others spat back, her face contorted in anger. ‘By word of the moderatus prime.’

Invoking the rank of their superior only worsened their case. It all seemed out of place.

‘You’re killing him.’

‘Want some as well?’ growled the first of the watchmen, lifting his baton towards her.

Ghelsa covered the distance in three strides, the last of which was accompanied by the upswing of the multi-tool. Powered by momentum, thick muscle and reinforced armature, the heavy metal implement struck the hyperezia’s chin at full speed.

Bone splintered and the guard toppled back, blood spraying from his ruined mouth.

Ghelsa was no warrior, but her augmented body gave her strength enough to compensate for a lack of skill. Her next blow shattered the baton raised to ward it away and smashed into the chest of the man holding it, hurling him backwards with a broken breastbone. A fist glanced off her cheek – nothing worse than she had suffered in one of her spats with Notasa or a fight in the narc-hide. Her return blow to the woman’s gut lifted the hyperezia off her feet, the air exploding from her lungs in a hoarse whistle. The guard crumpled, gasping, while the remaining three backed off, their rods held warily before them.

The spindle-wrangler glanced down at their victim. He was caked in blood and garbed in the robe of a tributai clerical worker – one of the log keepers, perhaps. He rolled to his back with a groan, revealing a face swollen about the eyes and mouth, his cool beige complexion looking jaundiced in the poor light. She didn’t recognise him.

Ghelsa hefted the stranger up onto her shoulder, thrusting the multi-tool threateningly at the others.

‘Leave it be. Tell Gevren the deed is done and no more need be said.’

The hyperezia did not look convinced, but they made no further effort to molest her as she backtracked towards the clanking chain of the ascender shaft.

With a quiet groan, the man roused as she lowered him, holding his body close to hers while she waited for the next platform to come around. He peered at her through the slit of a bloodshot grey eye, child-like against her mass.

‘Danger,’ he croaked.

‘No, you’re safe now,’ she assured him, moving her arm protectively around his shoulder as she darted a glare at the guards, who were tending to their own injured. ‘Well, relatively safe.’

‘All of us,’ whispered the man. ‘Hereteks.’

The platform rattled past and Ghelsa missed it, distracted by this statement.

‘The princeps is a traitor,’ the man continued wheezily, every word a clear effort through the pain. Whoever he was, Ghelsa admired the sheer will it must have taken for him to remain conscious. ‘Will doom… us all.’

‘Says who?’ Ghelsa was startled, but she had enough presence of mind to drag her companion into the lift when the next platform appeared.

The man said something else, but it was lost in the noise of the conveyance.

‘What was that?’ Ghelsa said, raising her voice. He pushed closer and she bent an ear towards his bloodied lips.

‘I… I am an inquisitor.’

Chapter 2

Az Khalak

Volleys of phosphor blasts lashed through the probing column of hereteks, reinforced by a thunderous barrage of heavier weapons fire. Their armour no match for the weapons arrayed against them in the carefully prepared ambush, the sixty-strong enemy force was halved in the opening seconds. White-coated skitarii used side streets to sweep around the back of their foes, swiftly surrounding them while kastelan constructs burst through broken walls, their phosphor blasters lighting the rubble-choked outskirts of Az Khalak.

Everything moved as Exasas willed it, each manoeuvre carefully controlled and timed for maximum kill-efficiency. Skitarii squads fell back and countered as easily as ve extended or retracted a mechanical digit. Robot maniples were vis fist, brutal but powerful, breaking all that they touched.

The beset rebel combatants tried to break free, massing a frontal assault to push on towards the open wildlands that surrounded Az Khalak. Exasas had foreseen that gambit and had prepared vis defensive protocols accordingly. Two squads of vis skitarii withdrew through the remnants of a storage house, emerging with several seconds to spare until they met the breakthrough with a precise, devastating fusillade.

And then the flourish that had taken several subjective years of study and calculation to formulate. The Exasas Corollary to Liberik’s Fourth Theorem: given sufficient pressure, an adequately armed opposition will naturally seek not the weakest point of an attack, but the weakest point within closely bounded timing markers. If exploited it meant a 0.43 per cent increase in kill-efficiency/temporal commitment.

[alert] <Static position eliminated.>

The transmission was one of seven that crowded into Exasas’ noospheric awareness, joining many others in vis memory queue for later assessment and formal archiving.

With reluctance, ve halted the simulation, rededicating the portion of vis processing metriculator that had been sub-adjourned to carry out the thought-exercise. The mathematical representations of the skitarii, their foes and the ruined outskirts froze mid-equation, the scene imprinted upon vis digital senses in as much stark detail as if it had been a real event.

More so, since it had been vis antarithms that had conducted the battle, playing the part of both aggressor and defender. Every triumph and loss had been Exasas’ to celebrate and suffer.

It certainly felt more solid than the destruction being wrought by the Casus Belli and the rest of the battle group. Exasas only experienced the carnage second hand, relying on the Titan’s processors and the servitor exchanges to gather some sense of the forces unleashed.

They had joined with the battle group as planned and entered the lowlands across the Asanaik River. Skitarii support platoons in reconnaissance transports had swept aside the enemy’s first-stage forces. The Titans had not even slowed to engage the lightly armoured and armed anti-grav skimmers.

The approaches to Az Khalak were a different matter. Several hundred enemy armoured vehicles and walkers were dug in across the hills along with considerable infantry support, for weeks an impenetrable barrier to the massed might of the Astra Militarum. Orbital defences within the fortress itself protected the siege lines from starship attack. Similarly potent anti-air guns prevented direct drop assault and anything but the most erratic high-altitude bombing and long-range shelling. In ferrocrete bunkers and kilometres of linking trenchworks and tunnels, the renegades were able to weather such attacks with relatively little concern. Consequently the defenders’ heaviest artillery was able to move close to the outer line with some impunity, extending the lethal zone around the citadel by several more kilometres.

The sheer scale of the endeavour had excited Exasas. Even though, as rebels, the enemy were equipped with standard Imperial equipment and materiel for the most part, which eliminated a large number of variables, the logistical calculations alone had required dedicated access to several logistaria slaved to the magos’ pattern-equations. Ve had recalibrated whole formulae to take into account the possible morale and discipline proclivities of a renegade faction.

While the magos had run thousands of scenario-specific data-threads in transit to the world, the Astra Militarum had employed the simpler but more costly approach of attacking with actual men and tanks. Repeatedly, despite mounting losses, in the assumption that their attritional rate was higher than that of the inhabitants.

They had been wrong.

The wreckage of previous armoured thrusts lined highways with burnt-out chassis and mounds of blackened corpses. The rockcrete roads themselves were little more than ribbons of cratered grey, their course plotted as much by the devastation written along their length as anything on a schematic chart.

Assaults cross-country had fared little better. Pounce-flachettes, sniper teams and las-traps awaited any pioneer corps that ventured forward to clear the heavier mines and self-propelled anti-tank guns. Tanks forging between the scattered copses of trees were soon targeted by the mobile artillery guns, each subsequent attack slowed and corralled by the metal corpses of its predecessors.

The Imperial Guard commanders reckoned casualties in the tens of thousands without hesitation, but the slaughter at Az Khalak had concerned even the logistaria corps attached to the Departmento Munitorum. It was not just an issue of manpower. New regiments could be raised without too much difficulty. Arming them proved a more difficult proposition, but many forge worlds had shifted full production to maintaining the arsenals of the Astra Militarum since the Great Rift had opened and war unlike anything seen in ten thousand years had engulfed the Imperium. To Exasas it was only a matter of scale and time. Given sufficient raw materials, the forge worlds could provide the war materiel for thousands of such forces across Imperial history – and had done so.

The real problem was starships, or the lack of them. The Imperial Navy was stretched to breaking, and every regiment lost on Nicomedua was another transport convoy that had to risk lengthy warp transit, each run to a recruiting world requiring armed escort lest it be lost even before it reached the battlezone.

Where such apocalypse had befallen the Imperial Navy and the Astra Militarum, the Titans of the Legio Metalica ventured without fear. Seven dedicated barges of the Legion carried the military might of ten times that number of transports for lesser mortals and machines.

Gevren: <I see that you have been amusing yourself with your simuladata, Xaiozanus.>

Though divorced from the noosphere when not at his station, Gevren was able to direct transmit to the magos via his MIU link. Exasas marvelled at the sophistication involved in digitally rendering and broadcasting just the exact tone of derision the moderatus prime desired.

Gevren: <I suppose you have to do something with all of that binaric potency you have been allocated.>

Before Exasas could retort, the noosphere crackled with command code as the plasma annihilator fired. Three sequential blasts seared into the ravaged foothills, devastating a stretch of revetments and gunpits.

Haili: <The true power of the Machine-God.>

Static danced with her thoughtwaves, the interference coming as her weapon cycled into its recharge phase and feedback data from the gunnery crew streamed directly into the moderatus’ thoughts.

Haili: <Even the humblest of our battle group will crush these miserable rebels.>

It was true – the Warhound Scout Titans that led the advance scoured trench and bunker with their turbo-lasers and mega-bolters. The twinned inferno cannons of Steel Wolf filled subterranean tunnels with cleansing promethium fire, sheets of blue flame erupting from concealed entry points and gunnery slits.

Behind came the Casus Belli and other Battle Titans. Reavers, Warhounds and Warriors laid down a constant barrage of shells, lasers and missiles, the devastation advancing across the scorched earth of the foothills like a bow wave before the massive war engines of the Cult Metalica. Quake cannons pierced metres-thick gates of outer towers while apocalypse warheads ripped craters from the earth, tossing men, machines and gravel high into the air. Gatling blasters, volcano cannons and plasma destructors made a ruin of the enemy that fled the attack, shredding, crushing and searing as the rebels abandoned their posts in their thousands and fleeing vehicles choked the broken roads.

Ignoring wordless protests and grunts of pain, Ghelsa hauled her companion off the liftchain just above the reactor decks. The ceiling was low, forcing her to proceed in a half-crouch, dragging the man across the smooth ferrocrete floor by the scruff of his robe. Level dekatriaz was a ’tweenspace, existing more for the necessity of the neighbouring systems than for any purpose of its own.

There were no lumens, but a faint luminescent lichen provided a little light to navigate between the thick columns holding up deck duadekaz above. The gurgle of cess drains and the hiss of the coolant loop told her when she was as far from any grating or other ingress as was possible.

The man flapped a hand at her, bruised and swollen from defending himself against the cudgels and kicks.

‘Thank… you.’

Ghelsa didn’t answer. She wasn’t at all sure whether she had just done something incredibly stupid or not. To distract herself, she fished inside her coverall and pulled out a slender flask of resynthesised alcohol. It was called ‘Machine-spirits’ by the more jocular members of the deck-crews, filtered out of the secondary fuel lines, diluted and flavoured to a variety of secret recipes from the various flora – and sometimes fauna – that eked an existence in the shadows of the downdecks.

She passed it to the man, who took a sip, coughed speckles of blood across her coveralls, and then took a longer swig. Ghelsa screwed on the cap and put the flask back into her pocket. She slipped out a wedge of drywater and pressed it between his lips. The inert chip of wood-like material activated with the merest contact of moisture to realign its molecules into a mouthful of water and vital salts. Intended for those on extended deep station in battle – with no access to the main water supplies – the drywater, like the Machine-spirits, had come her way via a more successful game of Omnissekh a few days earlier.

The stranger fumbled at his robe, checking the pockets in some agitation. He sat up, swayed for a moment as dizziness struck him, and then resumed his increasingly desperate search.

‘No, no, no,’ he muttered. He raised a hand to his head, wincing. ‘Damn it!’

‘What’s the matter?’ Ghelsa helped him sit up, one hand on his back.

‘My sigil. My Inquisitorial sigil. Gone. That serpent took it!’

‘How convenient,’ said Ghelsa.

‘What?’ He looked at her through the drying blood and bruises. ‘You think I would pretend to be an inquisitor?’

‘What seems more likely to you?’ Ghelsa sat back on her heels, the multi-tool still in her hand just in case. ‘That the moderatus prime of an Imperator-class Titan is a heretek and ordered the killing of one of the Emperor’s inquisitors, or that you’ve been caught impersonating one?’

The man’s shoulders slumped and he gazed down towards the hard floor.

‘I’ve failed. My pride… I should have known better.’

‘Let’s idle the gears a moment,’ said Ghelsa. ‘My name is Ghelsa vin Jaint, tributai second-class, specialising in mass mechanics. I tighten and loosen things. And occasionally hit them. I don’t know whose robes these are, but you definitely aren’t a tributai.’

‘You can call me Harkas. Ossissiru Harkas is the name by which I currently am known. I am, as I claim, a member of the Holy Orders of the Emperor’s Inquisition. And what I say is true. Your princeps intends to turn over the Casus Belli to the forces of the traitors.’

Ghelsa slowly absorbed this, not sure what to believe.

‘So how did you end up here?’

Wildfires raged through the foothills, the thick smoke obscuring more distant defences and the citadel itself. The smog was no obstruction to the noospheric-enhanced senses of the Casus Belli, whose targeting matrices could pinpoint a firing solution in pitch blackness up to the extent of a planet’s curvature.

The flare of white lasbeams, the startling blue hue of plasma and the flames of missile detonations lit the smoke. Grey-armoured vehicles swarmed like insects through the long grass.

Exasas registered all of the standard and non-standard visible spectrum data without any sense of connection. Ve found far more enlightenment from vis metriculated decoding of the scene. Projectile velocities and impact forces clamoured for attention among the arc of temperature gradients, intersecting geometries of firing angles and the ever-present kill-efficiency calculations.

Improving – perfecting? – this last factor had become Exasas’ lifework. Even the one-sided slaughter playing out before ver currently varied between a 98.8 per cent and 99.1 per cent efficiency. Vis complex calculations took into account the expenditure of energy and resources as well as received damage, and also a unique declining weighting based upon time expended.

The main battery boomed, causing the superstructure of the Imperator to shudder. Trajectory angles superimposed upon Exasas’ thoughts fed from the noospheric link of the moderatus prime. The explosion ripped away the top of a fortified hill, hundreds of tonnes of earth and ferrocrete turned to falling dust and grit littered with body parts.

Exasas flashed back to Gevren with a sub-packet of controlled amusement.

Exasas: <Eighty-nine point seven per cent.>

Ve transmitted targeting data for a few metres to the left of the impact point, where the reinforced structure of an ammunition store jutted intact from the debris. The magos sent scans from a recon overflight made two days earlier that highlighted the sensor returns indicating the existence of the chamber.

Exasas: <Had you incorporated this int-data within your assessment, you would have improved your kill-efficiency by four point six per cent. You are wasteful with the Machine-God’s bounties, Zerkei.>

Gevren: <Your concern is misguided, Xaio.>

The moderatus’ use of the truncated form of address was particularly petty.

Gevren: <One hundred and forty skitarii and their dominus is a considerable expense of materiel and energy to leave idle.>

It was hard to argue against that point, though Exasas’ equations contained a contingency formula to take into account periods of necessary dormancy.

Gevren: <You still chase the false hope of promulgating your theorems to the Metalican Council. You think you are the next Adanadin Phrex, perhaps? Or do you consider yourself on the level of the great Gyduang Acosu? It has been more than a thousand orbits since a magos dominus altered the Metalican Protocols, for good reason, but you have the hubris to think that you can. Your previous two attempts failed, and so will your next. The council has run out of patience – if you continue to test them you will be fortunate to command a manufactory garrison squad.> [emphasis modulation] <You are deluded, Xaiozanus.>

The note of pity that accompanied the last statement irked Exasas more than the contempt that had started the exchange.

Exasas: <We have entered paradigm-changing times, Zerkei. What was once accepted even on Holy Mars is now thrown into doubt.> [theory] <If the roots burrowed deep by Godwyn, Sakshuis and Land are being ripped free, there is every chance that the Metalican Grand Council will be willing to adopt my revisions of the strategos programming.>

A flare of derision accompanied the next transmission.

Gevren [rebuke]: <You refer to Bellisarius Cawl.>

Exasas: <For ten millennia he laboured, manufacturing the greatest advancement of our understanding of the Machine-God’s will seen since the Imperial Incorporation.>

Gevren: <Mars has forwarded accusations of tech-heresy against Cawl.>

Exasas: <Metalica has not. And there is dissent among many other forge worlds.>

A flurry of notifications spat into the awareness of the magos and moderatus. It was a substrand of a strategic inload redirected from orbit via the landing barge’s telemetry. Other such substrands were being apportioned to the other Titans, as well as the accompanying skitarii forces and the Astra Militarum generals monitoring the Titan advance.

The data-blurt contained two important pieces of information. Exasas split vis cogitator bypasses to consider them simultaneously.

Both of these revelations were accompanied by unknown agitations in the noosphere, hinting at the possibility of heretek broadcasts between the two anomalies.

Gevren’s noospheric presence disappeared instantly, at the same moment that Exasas severed vis connection to combine all available synapses and processing structures into analysis of this fresh information.

It took fourteen centiseconds for the magos dominus’ threat assessment protocols to issue a preliminary warning. It was echoed through the noosphere by logistari and analytika programs all reaching the same conclusion.

<ENEMY REINFORCEMENTS>

While verifying this tactical estimate, Exasas’ neural network extrapolated the possibilities, inferring reasoning and potentialities from the known data. One theme quickly established itself. The enemy knew the extent of the Legio army being sent against them. Despite the terrible losses already suffered, the rebels had chosen to dispatch further forces against the incoming Titans.

The Logi Superior ventured an early analysis.

Monderas [theory]: <Desperation.>

Exasas [inquiry]: <Why not commit them earlier? Why was the line not held?> [theory] <Even in desperation, better to bolster an intact defence than one that has started to falter.>

The power of Casus Belli’s latent machine-spirit quelled all other noospheric chatter.

Iealona [inquiry]: <You have an explanation, dominus?>

Algorithms raced into action as Exasas verified vis initial findings.

Exasas [theory]: <There is a high probability that this movement signifies a trap.>

The inquisitor – if such he truly was – stroked a hand across his forehead, soothing away the furrows. When he spoke, he gazed across the half-deck, his voice quiet but assured.

‘I was guided to the Casus Belli by my readings of the Imperial Tarot. When I–’

‘Wait. Of all the wars and Titans across the galaxy, you were led to the Casus Belli? That’s like finding a flange-nut in a spoil heap.’

He darted a look of annoyance at Ghelsa. She returned it with a blank stare, a reminder that it was not her that needed help. He backed down, mastering his impatience with clenched fists.

‘I was in transit to Nicomedua already. The presence of…’ He licked swollen lips, hesitating. ‘Renegade Mechanicus acolytes are of particular interest to me. My specialism, you might say. I was already drawn to the relief fleet by the news of the uprising and its support by traitors of the Dark Mechanicum. Conducting my standard readings of the Imperial Tarot, seeking insight into how best I might intervene in a worldwide conflict, I was guided by the Emperor’s will to the forces of the Iron Skulls – your Legio. I was able to gain access to the landing barge while it was in orbit, and brief investigations, coupled with ciphered communiqués from sympathetic agents within the Astra Militarum intelligence structure, convinced me that something was amiss on the Casus Belli.’

The thud of boots on the deck above and the clatter of the chain-lift reminded Ghelsa that they were still quite easy to find. Stooped under the bracings of the level above, she ushered Harkas further into the darkness. It was almost pitch black, but the man moved without hesitating, negotiating intersecting braces that could trip a stray foot, ducking beneath the potential garrottes of cable tangles. Even with her knowledge of the space – it being one of a handful of truly private areas in the downdecks – Ghelsa banged her head twice and stubbed her toe.

‘Just there,’ she said, pointing with the multi-tool at a recess between a flue rising from the pelvic motors and a downdrain that connected the holy decks to the vaporiser inlets of the sewage vats. ‘So you stole a tributai robe and managed to sneak aboard during the drop, I’m guessing.’

‘That is correct.’

‘And then showed your proof to the moderatus prime?’

He did not answer immediately, the pause raising Ghelsa’s suspicions again. She adjusted her grip on the multi-tool.

‘You have proof of everything you say, right?’

‘I am an inquisitor – my word is sacrosanct.’

‘You really believe that.’ There had not been a hint of indecision or self-consciousness in his voice. ‘Everyone is supposed to believe what you say, because you say you’re an inquisitor?’

‘My authority is absolute. Not even the Fabricator-General of Mars can gainsay my command.’

Ghelsa nodded weakly. ‘I see.’

‘You do not see, and you will not, because you must scrape an existence among these lowly decks.’ Harkas said the words forcefully, but not out of anger, it seemed. Ghelsa railed at the use of ‘scrape’ as a definition of her life, but Harkas continued before she could offer protest. ‘You can no more know of my perspective than you can imagine what it is to be princeps of this mighty war engine. You are a cog within the machine, not the hand that guides its operation.’

‘I’ve seen exactly what can happen to this mighty war machine if the wrong cog is out of place,’ Ghelsa said hotly, shoulders bunching.

‘Exactly!’ His insistence unnerved her, like a locomotive on tracks that could not be diverted, heading directly through whatever stood in its way. There was not an atom of compromise in his bearing. ‘The cog is important, but it cannot be allowed to see the vaster machine. It must turn its course and bear its load without questioning its place in the mechanism, trusting to the other cogs and belts and engines that move around it.’

‘So I must trust you, simply because you say you are an inquisitor? I didn’t understand too much of the logical teachings we’re given, but I know a circular argument when I see one.’

He sighed, seemingly in disappointment rather than vexation. He bowed his head, his voice dropping to a whisper.

‘You are not the first to point out the fallibility of my position.’ Harkas flexed his fingers, whether in frustration or pain it was impossible to tell. ‘The moderatus prime denounced me to the hyperezia and took away my sigil, ordering that I be summarily and quietly disposed of. You are the only ally I have on the Casus Belli. You might be a small cog, but you understand enough of the machine to help me disrupt the hands of those that guide it.’

He looked directly at her, his eyes shining in the gloom.

‘You can save the Casus Belli, Ghelsa vin Jaint.’

The first real indication that the enemy were preparing for a counter-attack was when they stopped retreating. Thousands of renegade infantry ceased their fleeing and started to dig in. Tank columns that had been heading full speed back to Az Khalak returned to their berms. Within minutes the entire front changed from one of mass panic to organised deployment.

The three Warhounds suddenly found themselves not chasing down ragged groups of survivors, but coming up against massed firepower. Shields flaring under intense battlecannon and lascannon fire, the war machines were forced to give ground against their smaller foes. The noosphere buzzed with concern as the princeps retreated their engines, seeking the sanctuary of distance.

This turn of events caused Exasas deeper unease.

Exasas [initiate command noospheric connection/inquiry]: <Was the rout part of a ruse? Have we been tempted into precipitous assault?>

Monderas: <Turning back a Warhound squadron is not comparable to halting the progress of a fully supported battle group. The Casus Belli alone is capable of meeting any threat from the citadel.>

Gevren [theory]: <When they see that we are not deterred, the retreat will begin again. The ruse is being played out now, trying to convince us they have reinforcements that can pose a threat. They are bluffing.>

Exasas ran this possibility through vis simulation routines while ve broadcast a readiness order to the skitarii under vis command. Weapons storage chambers were opened and heavier armaments distributed to the squads as they prepared themselves for disembarkation.

Monderas [inquiry]: <What are you doing, dominus?>

Exasas: <Being prepared. There are considerable underground defences ahead. It would not be prudent to proceed against an unknown foe while also allowing the enemy subterranean shelter.> [emphasis modulation] <My company will be ready for defence clearance.>

Gevren: <We are not stopping, Xaiozanus. The command was clear. Az Khalak must and will be broken by the end of the day.>

Exasas: <The perceived transitory time of the local star is an arbitrary timeframe to attach to such a significant endeavour.>

Gevren: <That is another reason why your theorems will never be accepted. You lack finesse. You discard emotional evaluations.>

Exasas [emphasis modulation]: <That is untrue! I have significant formulae to account for biological factors such as hormone levels and fear responses. It is you that believes victory only comes with utter destruction of the foe.>

Gevren: <A result of commanding such powerful weapons.>

Exasas pulsed the digital equivalent of a grimace and contemplated the emerging battle-data. Despite their withdrawal, the Warhounds found no relent. Having been pushed back out of proximity to the rebel forces, they were again targeted by the heavier artillery in the secondary defence line. Plasma warheads rained down from mobile launchers, turning the ground to glass amid the flicker of overloading void shields.

Steel Wolf reeled as the second of its energy screens disappeared with a purple flash. Caught in a maelstrom of artificial starstrikes, the Warhound back-stepped, but in his haste Princeps Kash did not pay attention to the broken defences through which he had advanced. One of the Scout Titan’s feet caught on the fractured remains of an entrenchment, toppling the war engine sideways.

Iealona [battle group/primary broadcast]: <Immediate support fire. Telemetrics, source position of incoming artillery strike. Omnissiah’s Temper, blind missile barrage to provide cover for the Steel Wolf.>

A data-blurt coursed into Exasas’ receptors from a sub-routine that had been analysing the enemy attack.

Exasas [direct trans/imperative/Omnissiah’s Temper]: <Negative on blind missile strike!> [direct trans/Iealona] <Princeps senioris, the enemy gunners have already established their target coordinates. They are firing from out of contact already. Blind missiles will obscure our scanners, and will not protect against indirect bombardment.>

Iealona [direct trans/imperative/Omnissiah’s Temper]: <Abort missile strike. Await orders.> [direct trans/closed/Exasas] <Suggestions, dominus?>

A flood of calculations poured through the magos, amplified via a subsidiary routine ve imported from Monderas. Verifying the findings took extra time, but given the nature of the conclusion Exasas had to be correct. As ve transmitted ve used a visual magnifier to concentrate on the stricken Warhound. Its leg had snapped in the fall, the ruined joint sending out showers of sparks while plasma blooms crept closer.

Exasas [direct trans/closed/Iealona]: <Sacrifice gambit. Steel Wolf cannot be saved. Suggest crew evacuation and increased telemetrics to determine course of incoming fire. Use Steel Wolf’s death to ensure our counter-blow eradicates the mobile artillery.>

A moment of reluctance ebbed back across the noosphere, a product of the princeps senioris’ biological sentiment. Exasas was saddened by the impending loss of the Titan, which had served Metalica and the Machine-God for over eight thousand years. That such a reign of a lord of battle would end in these fickle circumstances was regrettable but unavoidable. The calculations were not wrong.

A flicker of a closed transmission rippled through the noosphere. Several pulmonary cycles later, the Warhound’s head burst free from its mounting, becoming a short-ranged shuttle that took the command crew a few hundred metres further into enemy territory. At maximum magnification Exasas saw figures clambering out of the torso access hatches – Tech-priest Elaxha and two of her tributai assistants.

A storm of plasma engulfed the forlorn Titan before they had climbed down the side of the war engine, bathing the view in white. Reducing magnification, the magos saw explosion after explosion wracking the Steel Wolf’s cadaver. Even while ve watched the demise of the Titan, the magos’ secondary cogitators scrolled energy output estimates across the view.

Monderas [battle group/datalog]: <Four enemy gunnery positions located. Targeting data attached. Warhound escape module position located.>

Exasas felt the inload of data across the noosphere, trickling through vis calculations like ripples in water, the equations altering as consequences cascaded through the algorithms. Ve was aware of substantial noospheric traffic as orders and new firing solutions flashed between the Titan crews, but the magos was not part of the dataloop. It was an unintended reminder that ve was not needed.

After the intense bout of cogitation the dormancy that followed felt empty. Beams of las-fire coursed across the hillsides while flights of armour-piercing rockets arced through the smoke, but to Exasas they were of little interest. It was with a sense of detachment that ve did not even calculate their impact velocities, and ve took only a passing interest in the kill-efficiency data streaming from the other Titan crews.

The Imperator’s hellstorm cannon thundered into life and a distant woodland disappeared in fire. Exasas barely registered the onslaught as ve accessed vis paused simuladata.

Ve wiped clean the battle cache and started the simulation again, increasing the aggression ratings of the defenders to provide a greater challenge.

‘That’s quite a claim,’ said Ghelsa. She rocked back on her heels, not sure what to do.

‘You’re not sure what to do,’ said Harkas. ‘If I’m lying, you need to turn me over to those thugs you rescued me from. If I’m not lying, that’s the last thing you need to do.’

‘You seem like a smart one – what would you do?’ Ghelsa looked for a telltale bulge of a weapon beneath his robes but saw nothing. The multi-tool still in one hand, she passed him a rag to wipe away some of the blood. He winced as he touched the coarse cloth to his cheek.

‘Benefits and losses,’ said the so-called inquisitor. His good eye took in everything, sizing up Ghelsa, observing their surroundings. ‘If I am not an inquisitor, what have you to gain or lose?’

‘Well…’ Ghelsa wasn’t used to this sort of thinking. She was usually faced with practical problems, not matters of logic. ‘You might kill me.’

‘True. But if I were an inquisitor, I might kill you as well. And if what I say is true, and the Casus Belli is turned against the Imperium, you would be purged along with the others of the crew not party to the plot.’

Ghelsa’s hands were sweaty and her heart throbbed. The man talked about killing her as casually as she discussed a number six rawl-line.

‘So, I’m in danger either way?’

‘You live and work inside a war engine of the Adeptus Mechanicus. Every time you go into battle you are in danger.’

‘That’s not the same. You’re talking about a very specific danger. I’ve never expected any of my crew-mates to kill me. Well, maybe once or twice, with the Machine-spirits in them… But that’s not the snarl we’re in.’ A dark thought crossed her mind and with it came a fresh surge of fear. ‘The tech-priests are going to come after you, aren’t they? Either the loyal ones or the traitors, whichever want you dead.’

‘That is an accurate assessment, yes.’

‘And now that I’ve met you, I’m involved.’ Ghelsa licked her lips nervously. ‘Whichever way the truth goes, I’m… an accomplice?’

‘The moment you struck the hyperezia.’

‘Great.’ She wanted to scream, but dared not take her eyes from the bloodied man. ‘That’s just incredible. You know what they do to hereteks?’

‘They will scald-blast you with the heat overload valves,’ replied Harkas. ‘It will melt off your skin and then down to the bone. Like burning alive, but slower and far more painful.’

‘That’s right. After the torture to recant, obviously.’ Ghelsa thought she would vomit, but managed to stop the reflex.

‘It is too late for you, Ghelsa vin Jaint.’ Harkas stood, as best the confines of the twixt-deck allowed, grimacing with pain. Ghelsa readied the multi-tool, but the man seemed barely capable of staying upright, much less violent action. ‘If I am an enemy of the Machine-God, you must report us both for the good of the Casus Belli.’

He turned an enquiring gaze on her, his eyes shadowed, blood crusted over his face.

She said nothing, still trying to weigh up her options. If he was in league with hereteks then he would try to dissuade her from going to her superiors to protect himself. Her implication in the plot was the defence he needed. Harkas was daring her to risk her own life.

‘You’re not the fastest of thinkers, are you?’ he said.

‘And you’re not the nicest of people.’

‘Inquisitors never are.’

A change in the timbre of the background noise interrupted Ghelsa’s train of thought.

‘We’re slowing,’ she said. After a few seconds she could identify the new rate of stride by the floor vibrations. Her eyes widened. ‘Battle speed! We must be nearing the enemy.’

Another sound drew her attention. Feet on the deck above, moving with purpose as the work crews attended to their battle stations.

‘I need to go,’ she said. ‘I’ll be missed at roll call.’

He held out a hand as she moved to pass him. ‘The hyperezia will take you. They will torture you to find me.’

His words sounded like a threat. Ghelsa pulled back and raised the multi-tool, her fear flaring as anger.

‘Try to touch me again and I will end you,’ she said, fixing him with a glare. He met her stare without reaction, his eyes as dead as the lenses of a vacuum mask. There was no fear there. Beaten almost to death, threatened with more violence, Harkas seemed utterly unconcerned. She had never seen someone with such conviction and self-assurance.

It all felt wrong.

Which, as an adherent of the Cult Mechanicus, was the worst possible reason for anything. Feelings – fleshy, subjective notions of emotion and belief – were no basis on which to make a decision. Even so, Ghelsa felt that Harkas was telling the truth. She couldn’t reckon the logic either way – her mind was not made to weigh the facts in that manner.

In the absence of orders or verifiable data, all she had was feeling.

‘Let’s assume you’re telling the truth about being an inquisitor,’ she said quietly. She scarcely believed the words were coming from her lips, dragging her deeper into the plot. ‘What’s your plan?’

‘I will reclaim my Inquisitorial sigil and use it to rouse the faithful tech-priests and oust the traitorous upper echelons.’ He said this as if it would be as straightforward as tightening a flange-nut or working the odds of a High Acolytist throw in Omnissekh.

‘And where is this sigil?’

Harkas’ eyes narrowed with anger. ‘The moderatus prime took it when I presented it.’

‘So it’s in the God-decks?’

‘The command centre, yes.’

‘How did you get in there the first time?’

‘Without enough guile. I had misjudged the plot, thinking the princeps senioris alone was corrupted. Now I must be more circumspect. There’s no telling who might be aiding the conspirators.’

She heard a change in the rattle of the elevator chains and held up a hand to silence him. They shrank back into the shadows as a handful of indistinct figures descended past, clinging to the links. Ghelsa recognised their work garb and a couple of faces.

‘Just tributai,’ she whispered, but she did not relax. Her subconscious interrogated every creak, moan and shudder from the surroundings, desperately seeking anything amiss. The Imperator Titan had always been her sanctuary, even in the midst of battle. Now it felt alien and hostile, the shadows concealing unidentified foes. ‘This sigil, that’s all you need?’

‘I am confident that the dominus of the skitarii garrison of the Casus Belli remains loyal. He will heed the warning of an inquisitor and relinquish the princeps senioris of command.’

‘We’re going into battle!’

Judging by his lack of reaction, Harkas didn’t fully understand the implications of this.

‘You want to remove the princeps in the middle of a battle,’ explained Ghelsa. ‘That has to be the worst idea I have ever heard.’

‘I see your point.’ The inquisitor paused, his jaw clenched. ‘I do not think the traitors intend to defect to the enemy while they are still with the rest of the battle group. Any treasonous activity would be met with immediate attack from the other Titans, and that is a battle even the Casus Belli cannot win. The princeps will need to engineer a situation in which her treachery can occur without witnesses. She will isolate the Titan and purge any loyal elements within the crew. That gives us a short time.’

Purge the loyal elements…

Ghelsa thought of Notasa and the other duluz, and tried to remain calm.

Harkas looked up, the sudden motion causing Ghelsa to flinch. His eyes glimmered in the darkness, and Ghelsa realised that his detached stare was due to implants, nothing more. He gazed through the decking, a silent snarl curling his lip.

‘More hyperezia are gathering above us. They have firearms. The search is beginning in earnest.’ His unnatural eyes dimmed when his gaze moved to her. ‘I cannot remain here any longer.’

Every time Ghelsa tried to think straight he put her thoughts into a spin. She searched Harkas’ face for any sign of deception, wondering if he was deliberately keeping her unsettled, but she was more skilled at reading pressure gauges than people. One thing was clear.

‘You need to get out of the downdecks as soon as possible,’ she said. ‘The hyperezia will be looking for you. If you can get into the akropoliz you can lose yourself among the skitarii and gunnery crews.’

‘I need your help.’ The inquisitor made the request without hesitation or shame. When he continued it was as if he were talking about another person rather than his own safety. ‘You recognised me as an impostor in an instant, and others will also. Without your assistance I will certainly be discovered and killed.’

And that was the truth of it.

Voices echoed down the conveyor shaft, harsh and inquiring, though Ghelsa could not hear the actual words. She caught the buzz of a crude vox-caster. Though she could not discern the meaning, she knew binaric cant when she heard it.

‘A tech-priest is leading them,’ she said with a shudder. ‘I know these decks well enough to run rings around the hyperezia, but a tech-priest…’

Ghelsa faced a simple decision. Either she helped Harkas, or she clubbed him to death here and now and hoped his corpse would buy her some clemency from the tech-priests.

He watched her, studying her face intently, perhaps looking for some warning of her decision. The eyes were likely not his only enhancement, and Ghelsa wondered if he was quite as defenceless as he appeared.

She took a breath, realising that sometime in the last few seconds she had decided to help him. The inquisitor, she told herself. If she thought of it in those terms the situation didn’t feel quite so terrifying, though no more real either.

‘That way,’ she said, pointing to starboard with the multi-tool. ‘There’s a ladder we can use. You go first.’

Even if Harkas was an inquisitor, Ghelsa wasn’t fool enough to turn her back on him.

Chapter 3

Setbacks

Iealona [datalog/concept/destruction]: <The traitors think they have won a victory, but they will discover that the destruction of our companion has earned them only the even greater wrath of the Omnissiah. Their resistance is an affront to the Lord of Mankind and their support of hereteks an insult to the Machine-God. Casus Belli is the instrument of vengeance that will lay low their works and raze them from the annals of history.>

The anger was not Iealona’s, at least not hers alone. The rage that empowered the broadcast came from the depths of the MIU, a vocalisation of the Casus Belli’s inner roar at the loss of Steel Wolf. The transmission was accompanied by a burst of imagery from the extensive battle-archives of the Imperator. Pic- and vid-capture displays of burning cities and annihilated fortresses flashed through Exasas. The Titan’s channelled thoughts played out to recordings of shell detonations and the shriek of plasma discharge, the voice of a war god writ in the language of death.

Haili [exalt]: <We are the messengers of fate.>

Gevren [exalt]: <In our vengeance we shall erase these blasphemies.>

Exasas tasked a minute portion of cerebral architecture to briefly acknowledge the sentiment, but felt no urge to contribute directly. The humans’ posturing was unnecessary. The Machine-God – as embodied by the Casus Belli – already knew full well the requirements of the enemy’s destruction. It had, through the offices of the Departmento Munitorum and the Collegia Titanicus, delivered the means for vengeance. Any further exhortation was inefficient and, for lack of a more precise term, ungracious.

Exasas [local transmit]: <We honour the Machine-God’s divine code with deeds.>

Gevren: <Some of us will.>

Exasas regretted vis outburst immediately and avoided further humiliation by redirecting full attention to the ongoing battle. Although their artillery support had been mostly curtailed, the rallied traitors continued to hold their positions against the Titan onslaught. For some time they had exchanged long-range fire with the Battle Titans, lighting up void shields with their ordnance while the weaponry of the Warlords, Reavers and Warriors shredded ferrocrete defences and immolated battle tanks in response.

Exasas [direct trans/closed/Monderas]: <I am encountering difficulty identifying the defensive paradigm we are facing.>

Monderas [direct trans/closed/Exasas]: <Your error may be in attributing a paradigm when no such thing exists.>

Exasas [direct trans/closed/Monderas]: <Your assessment may be correct, but it is advantageous to attribute to intent rather than accident if one wishes to maximise the efficiency of response.>

Monderas [direct trans/closed/Exasas]: <Very well, I will indulge you.>

Exasas [direct trans/closed/Monderas/speculative]: <Further resistance increases the likelihood that previous retreats were intentional.>

Monderas [direct trans/closed/Exasas/speculative]: <Failure of earlier retreat may explain increased resistance.>

Exasas [direct trans/closed/Monderas/speculative]: <Previous retreat was precipitous, disproportionate to damage inflicted at that stage. Artillery support has been neutralised yet the enemy seem more determined now than earlier.>

Monderas [direct trans/closed/Exasas]: <Accepted. High probability that initial retreat was false. What is your extrapolation?>

Exasas [direct trans/closed/Monderas]: <I am still at a loss to explain the benefit of such a manoeuvre. If the citadel contained forces capable of meeting the threat, it would be more efficient to deploy them at the outset, or later, when we have expended significant resources breaking the line. The enemy have given ground for no advantage and have, to use an analogy from gambling parlance, shown their hand too early.>

Monderas [direct trans/closed/Exasas/interrogative]: <Analyse strategic factor: geographic advantage of new positions.>

Exasas [direct trans/closed/Monderas/gratitude]

The suggestion was precisely what Exasas had failed to identify. The staged retreat – masquerading as unintended rout – masked the adoption of the new positions across the hills around Az Khalak. Ve ran several topographical analyses of the routes to the citadel, but nothing significant drew vis attention. If it was not the actual physical locations of the defenders, there had to be some other reason why they had pulled back one and half kilometres in the face of the Titan assault.

Exasas [analysis request/closed/lexmechanica datalogs]: <Scrape historical records for reference to long-range weaponry within the citadel Az Khalak.>

Lexmechanica datalogs [request response]: <Last report of citadel defences includes fourteen quake cannons mounted on mobile turret arrangement. Each quadrant defended by up to eight cannons with overlapping firing arcs. Range increments increase with elevation. Maximum range twenty-five kilometres with acceptable accuracy.> [caveat/dating/archive material]

Exasas had been immobile during vis exchange with Monderas and the data-scrape, all energy directed towards systems monitoring and communication. Agitation stirred vis mechanical form, causing the magos to extend vis articulated limbs as an expression of disturbance.

The main displays contained a picture of ongoing devastation as the battle group’s advance across the hills continued. Despite the firepower levelled upon them, the rebels were far more stalwart in their defence than against the initial assault, further adding to Exasas’ suspicion that the first withdrawal had been a feint. Ve reiterated vis concern in a blurt-transmit-repeat-stub to the princeps senioris, not wishing to distract her further during lethal engagement.

The distance-to-objective monitor, which had been calibrated for the central keep of Az Khalak, read fifteen point three kilometres. This placed the Imperator and its companions well within range of the city’s main guns. Even so, the quake cannons were a known quantity and it still made no sense to Exasas that the defenders would have laid their outer defensive line beyond the range of their most potent weapons.

Ve initiated another communication with Monderas but kept the transmission open for the other tech-priests, moderati and princeps senioris to intercede if they wished.

Exasas [direct trans/Monderas]: <We are approaching the targeting arc of Az Khalak’s primary weapons systems. It would be prudent to anticipate counter-attack under the cover of the citadel batteries.>

Monderas: <Enemy targeting scans have been detected. Firepower quotient calculated for eight Thor-pattern quake cannons is still within tolerable impact parameters.>

The magos dominus broadened vis transmission to ensure that the rest of the command crew received the following exchange. Ve sub-stranded a threat-potential-unease gradient to convey vis growing anxiety with the situation.

Exasas [imperative]: <Extrapolate firepower quotient of quake cannons combined with nearby rebel personnel and armoured vehicles.>

A buzz of data flowed through ver, whirling through algorithms like blood pumping along vis vessels, powering exponential calculations rather than physical movement. Exasas matched the data with vis archival stores regarding the defences of the Imperator and then each of the Titans in attendance.

Exasas [imperative]: <Concentrated fire upon one target will lead to total destruction of Warlord class and below.>

Iealona [inquiry]: <Progression estimates before retaliation?>

Monderas had already been plying the calculations through his own cogitators and answered immediately.

Monderas: <Depreciating enemy capability at thirteen per cent per standard minute. Warlord destruction estimated at four minutes. Reaver and Warrior destruction estimated at three minutes.>

Gevren: <At best they could destroy one of the Warlords and strip the shields of another.>

Exasas [theory]: <Or eliminate two Reavers.>

Monderas [inquiry]: <To what purpose? Annihilation of Az Khalak is inevitable even with worst projected losses to the battle group.>

Iealona: <Never rule out blind defiance or spite as a motivation.> [theory] <The enemy know they are defeated, but they wish to hurt their conquerors before they fall.>

This idea intrigued Exasas and ve archived the thought for later incorporation into vis theorem. A more pressing matter attracted the attention of the entire command crew when proximity surveyors scrambled into life, detecting a growing number of the power sources that had left the citadel.

Monderas [request]: <Surveyor banks require more power for resolution at this range.>

Iealona [plasma chamber/imperative]: <Divert ten per cent output to scanner arrays from motive engines.>

Seconds later alarms flared across the noosphere as the guns on the walls of Az Khalak opened fire. Trajectory data and payload assessments seared across Exasas’ interlocution circuits. Again it was the logistari prime that responded sooner, interconnected with the main surveyor arrays rather than relying on secondary reporting as Exasas was forced to do by dint of vis lesser role within the command crew.

Monderas: <Full bombardment, targeting the Indomitable Guardian and Will of Iron.>

The two Warlords halted as the shells arced towards them, diverting power to their void shields so that each was encased in a glimmering hemisphere of energy. Discordant reactions fluttered through Exasas as ve realised that the gunners in the citadel had made an error.

Exasas [inquiry]: <Why are they splitting fire?>

Quake cannon rounds, each capable of levelling a building, slammed into the void shields of the two Warlord Titans. Arcs of power leapt as the energy fields shunted the explosive energy of the impacts into warp space. To Exasas’ visual senses a coruscation of green and blue flowed around the war engines, while in vis metamathical analysis the conflicting energy waves collided in pleasing spiral patterns.

Flurries of anti-tank fire and smaller-calibre guns scratched across the remaining shields. None of them were powerful enough to land a debilitating blow, but in concert they gnawed at the Warlords’ defences.

Exasas felt the Casus Belli slow further as more power siphoned from the legs to the weapons, powering up the Imperator’s primary guns. The rest of the battle group thrust onwards, their weaponry of no use against the city at this range. They targeted their ire against the troops still manning foxholes and gunpits, wading into the criss-cross of defensive embrasures and trenchlines like skitarii soldiers picking their way across uneven ground.

The thrum of potential filled the noosphere as the plasma annihilator powered to full energy, the anticipation of Casus Belli’s spirit spilling out through its princeps. But even the Imperator’s greatest weapon could not hope to reach a foe still many kilometres distant. The ravening star that roared forth seconds later crashed into a company of traitor Leman Russ tanks that had attempted to push around the flank of the battle group. Five disappeared in a flash of incandescent power and startling energy co-efficients, the ground where they had been replaced with a glass-sided crater and a rising cloud of vapour. Streaks of molten plasteel marked the crater edges, where cooling droplets of what had once been machines fell like rain.

The hellstorm added a wrathful stream of shells to tear a fresh canyon through the ridge of a high hill ahead of the Casus Belli. Whole platoons of traitor skitarii and rebelling defence troopers died in the initial hail; as many again were crushed when the remaining hillside slipped away, tumbling thousands of tonnes of earth and rocks on the fortifications built across the valley.

A kill-efficiency of 96.4 per cent sent a pleasurable quiver of appreciation through Exasas, but the momentary elation did not detract from the magos’ underlying pensiveness.

Ve sidelined an ongoing simulation to make more processing power available to assess the enemy’s potential objectives. Faster and faster ve ran prognosticating algorithms, shutting down sensory inputs and redundancy systems to concentrate all available cogitation on the matter. Swathed in virtual and visual darkness, the magos let the equations dance through ver, streaming together into a single conjoined extrapolation.

A brief lance of formative data broke the meta-silence when the city batteries opened fire again. Targeting predictions seemed amiss at first, locating the point of impact among the Reavers now spearheading the advance, rather than upon the Will of Iron and Indomitable Guardian, whose shields were already partially overcome.

Exasas took the data as truth, sparing nothing to re-evaluate the trajectories. Instead ve paused all other calculations to hone the forecast antarithms – those parts of vis program that attempted to emulate the enemy’s intent. One consequence pulsed through the findings, repeated again and again as ve reran the data flow.

Exasas [imperative]: <We have stopped. As have the targeted Titans.>

Monderas: <Delay is of no consequence to the success of our mission.>

Iealona [inquiry]: <What is the significance?>

Gevren: <We have not stopped.> [emphasis modulation] <We have been halted. To what purpose?>

Before Exasas could examine the situation further, a new development interrupted vis analysis.

Monderas [alert]: <New power source signals identified as super-heavy armoured vehicles.>

Iealona [interrogative/emphasis modulation]: <Type? Pattern? Do they have Titan-killers?>

Even disregarding the princeps senioris’ overly emotive phraseology, the thought caused Exasas some trepidation. There was a high probability that the heretek forces had turned dedicated anti-Titan platforms such as the Shadowsword, Stormblade and Doomhammer. Was the emergence of the super-heavy tanks sufficient to justify the loss of lesser vehicles and personnel in the feint? Had they been lured closer to the city so that these vehicles could bring their attack to bear before detection? Was there sufficient time to combat the emergent threat? Conflicting threat value revisions cascaded through the magos’ systems so fast it bordered on paralysis.

Monderas [direct trans/closed/Exasas/rebuke]: <Your negative dataflow is infecting my core correlations. You are encountering an open-loop paradox. Withdraw your inquiries.>

Exasas [direct trans/closed/Monderas/apology]

Exasas: <Insufficient data to submit analysis.>

Gevren [rebuke]: <Your input was not requested, Xaiozanus.>

Exasas [imperative]: <Enemy anti-Titan reinforcements cannot account for adopted strategy. Seek further data.>

Iealona [rebuke]: <Do not clutter the noosphere with conjecture, dominus. If you have no pertinent analysis, we must concentrate on combating the enemy as we encounter them, not fighting phantasms of your calculations.>

Exasas whipped back vis noospheric presence like a prey creature fleeing for its burrow. Leaving only a narrow data-tendril to absorb a trickle of incoming data, the magos dominus retracted all of vis ongoing simulations, which had multiplied a dozenfold while examining the possible attack vectors of the new traitor forces.

Thwarted both by the censure of the princeps senioris and vis own cogitational limitations, the magos dominus busied verself recalibrating several non-functional secondary systems – a form of digital fidgeting. Only dimly aware of the continuing datastream, ve spared just a fraction of vis calculating processors to monitor the arrival of three Shadow Sword Titan-hunters, escorted by a similar number of Baneblade and variant super-heavy tanks. The formidable engines unleashed their firepower against the lead Reaver, forcing it to halt to return fire with its plasma blastgun and a storm from its missile launcher amid the cerulean detonations of its void shields.

Monderas [alert]: <Citadel batteries firing again. Renewed targeting of Will of Iron and Indomitable Guardian.>

Frustration coursed along Exasas’ datastream and remaining nervous system, leading to a flurry of physical agitation as the released energy demanded to be expressed. To return the weight of the quake cannons’ fire against the Warlords was even more illogical than the first salvo. The Titans had restored their void shields and were advancing again, but they were far from a direct threat to the wall guns. It seemed that Monderas had been correct in the assumption that the defenders sought only to delay the attack.

Delay.

What could be earned by slowing the assault if it was not to concentrate the available firepower? How could the traitors gain advantage from stalling the battle group’s attack?

Evacuation was a possibility, but readings did not suggest any mass withdrawal from the city. Another potential reason was to gain time for the preparation of fresh forces as yet unready.

This seemed a greater probability and Exasas examined it further, pausing other avenues of inquest. Posing the question to the antarithm circuits, the magos tried to position verself in the thought processes of the rebels. In reversed circumstance, what was the solution to the problem posed by an attacking Titan battle group?

An equally dominant response.

What weapons system was more dominant than a Titan battle group?

Monderas [alert]: <Orbital energy surge. Detecting surveyor scans from orbiting starship.>

Target alarms blared across the Imperator and echoed through the noosphere from Titan to Titan, a ripple of activity that would have been taken for panic among living soldiers.

The transitory piece of orbital data from earlier surfaced through Exasas’ calculations, too late to be of use.

What Ghelsa had described as a ladder was just a series of square hooks fastened to the wall, each barely large enough for a hand or foot. Harkas crouched at the edge of the semicircular opening in the floor and looked up, his eyes flashing again as his augmented vision pierced the gloom.

‘It is empty,’ he declared. The inquisitor reached out a hand to the nearest hook, his jaw visibly clenched in pain.

A clatter from the direction of the chain conveyor announced the arrival of several hyperezia. Lantern beams swept across the twixt-deck, casting roving shadows. One of the lights passed across the two fugitives and a triumphant shout announced their discovery. More lamps flashed in their direction, bobbing as the guards carrying them ducked into the shallow space.

‘You’re too weak to climb,’ said Ghelsa, easing Harkas aside. She hooked two fingers onto a rung, locking them in place. She grabbed a handful of the inquisitor’s stolen robe and stepped across, bare toes finding purchase on another step. In situations like this, and when clambering to even more inaccessible locations in the downdecks, she was glad of her reinforced toes even though they prevented her from using footwear.

Harkas wriggled in her grip, making it hard to keep a tight hold. ‘Relax, I’ve carried heavier than you up and down these shafts.’

The inquisitor went limp as she pushed with her leg and swung her fingers up to the next hook. She found her rhythm almost immediately, quickly climbing while the shouts of the hyperezia increased below. The ladder space brightened and dimmed as they directed their lamps after their quarry, the light glinting from the rungs and Ghelsa’s exo-skeleton.

‘Where… are we going?’ asked Harkas.

‘Up,’ grunted Ghelsa, which was the only answer she had. ‘Let’s just get some distance and then we’ll worry about where next.’

Blinking, they passed into the lumen-glare of the duadekaz. The climbspace was at the end of an access corridor that ran to the central arterial route, which was thankfully devoid of occupants. Ghelsa did not look down, but knew that the hyperezia would not be far behind.

‘I’ll outpace them,’ she assured Harkas, continuing towards the entekaz – the eleventh level, as the tech-priests reckoned their numbering downwards from the holy decks.

‘Can you move faster than vox-waves?’

A high-energy bolt flashed down from above Az Khalak, slamming into the shields of the Hammer of Metalica, the foremost Reaver Titan. Its void generators already overloaded by the super-heavy tanks and incessant fire of smaller foes, the war engine had no defence against the orbital strike. Exasas registered the tremendous energy outflow – surmising a lance-weapon had fired – at the same instant that the beam split the Reaver in half from carapace to groin. So swift was the killing stroke that the reactor did not explode, but instead roiling plasma spilled like guts from the devastated Titan as it fell sideways, consumed by the fire of its own power source.

The death-shock resounded across the noosphere, silencing all traffic for several milliseconds.

Exasas, mostly disengaged from the dataflow, responded first.

Exasas [battle group/imperative]: <They can only target accurately if we are static and of sufficient distance from their own super-heavy vehicles.>

Gevren [rebuke]: <Late wisdom is no wisdom at all.>

Exasas was about to respond that the moderatus prime had not foreseen the eventuality, but a general broadcast from the princeps senioris blanketed all other signals. Casus Belli’s rage flowed across the carrier waves with her words.

Iealona [general command/imperative/concept]: <All forces, direct attack! Full speed, engage while mobile. Let the skitarii support finish the survivors – focus all firepower on the Titan-killers and citadel.>

The transmission ended with a monstrous swelling of noospheric pressure, culminating in a long blast from the Imperator’s war sirens. Its deafening mechanical roar echoed across the hills, the war sirens of the other Titans answering with their own cries for vengeance.

They reached level dekaz before noise and lights above them warned of waiting hyperezia where the ladder ended two levels above. Ghelsa leapt away from the wall, landing easily on the plate decking with Harkas still firmly in her grip. She lowered the inquisitor to the floor and sucked in lungfuls of air. While the exo-frame boosted her muscles it did nothing for her constitution – she had been rebuilt for strength, not endurance. The climb had left her heart hammering against her ribs, her chest heaving. Mostly the climb, she admitted to herself, still feeling the fizz of shock coursing through her.

‘We need to keep moving,’ warned Harkas, eyes shining as he scanned their surroundings.

Ghelsa moved to the archway where the shaft joined the main crew space. The eighth, ninth and tenth decks were a contiguous maze of walkways, ladders and stairs, built around the main power conduit that ran from the reactor up to the holy decks and akropoliz. Through the mesh of the decking she saw white-robed priests attending to the power relays, their bionics reflecting the amber glare of readouts and indicator lumens as the power output increased.

Around them bustled the duluz of the Cult Metalica, lifting bracing spars, carrying spare cabling up from the stores, attending to the other preparations for battle. The air was thick with sweat and humidity from the taxed heat exchanges. Pairs of small children darted around with cloths and buckets, wiping moisture from the rails and steps and drying off pipe housings, circuit plates and access ports in a never-ending struggle against corrosion.

Among the half-naked labourers drifted the epilekhtoz in robes of white edged with red, occasionally barking remonstration at some real or imagined laxity. Not full tech-priests, they were nevertheless natives of Metalica and hence considered superior in the eyes of the hierarchy.

Ghelsa strained for sight of a familiar face, but she did not often stray below deck eptaz. Even so, she knew the quickest way up to the akropoliz.

‘This way,’ she said, flicking fingers for Harkas to follow as she stepped out of the shaft. She headed left along a walkway and past the circular housing of the starboard gyro. Feeling the deck beneath her feet was a comfort, a reassuring touch after the preceding minutes of uncertainty.

‘When I get you to the akropoliz, I’m done,’ she told Harkas. She squeezed between a vertical pipe and the ferrocrete brace of an abdominal armour plate. ‘You should be able to find your own way to the God-decks from there.’

‘Of course.’ The inquisitor did not look at her as he replied, his attention drawn to something above them.

‘And then I suppose I’ll have to find somewhere to stay out of sight until you’ve done what you need to do.’

She pushed up a loop of flexible hose and ducked beneath it, holding it for Harkas to follow.

‘You know, when they’ll stop hunting me,’ she continued. ‘You’ll do that, right? You’ll call off the hyperezia?’

‘I would suppose so.’ He looked up again, brow creased. ‘There are a number of them stationed at a gateway on the deck above. We appear to be moving towards them.’

‘Damn.’ Ghelsa grimaced. She stopped and tapped a finger to the cog symbol in her forehead, a habit she had when thinking, as if she could make her brain work faster. ‘They’ll have a squad at the port stair too. This is going to be harder than I thought. Maybe we could scale the tertiary dampeners.’

As she spoke she led him out into the main concourse, stepping in behind a trio of tributai carrying coils of replacement generator cable. There were other tributai moving about their duties, but Ghelsa could not see any tech-priests nearby.

Harkas slipped a ring onto his left hand – a golden band with what Ghelsa first took to be a ruby, but then realised was a focusing crystal for a laser.

‘You have a digi-weapon?’

His glare warned her that she had spoken loudly. She glanced around nervously, trying to hide him behind her bulk. Nobody seemed to have heard among the constant clanking of the Titan’s motion. She dropped her voice to a whisper. ‘What are you going to do with that? Why didn’t you use it on the hyperezia?’

‘To answer your second question first, I had to hide it to prevent confiscation,’ he said as they mounted a short flight of steps to a curving gantry around the central mass of the Titan’s main power conduits. ‘And you know the answer to the other question.’

She stopped, blocking the inquisitor at the top of the stairs.

‘You can’t kill the hyperezia,’ she said, remembering to keep her voice low despite a fresh surge of apprehension. ‘They’re not hereteks – they’re just doing what the tech-priests order them to do.’

‘You had no compunction when you struck them to rescue me.’

‘I wasn’t trying to kill them, and I wasn’t really thinking about it.’

‘If I fail, hundreds of thousands of the Emperor’s servants will be lost.’ Harkas moved to step around Ghelsa, but she barred his route. ‘This is an awkward time to have a moral quandary, Ghelsa vin Jaint. When the plot has been thwarted I will happily debate you on the subject of life’s value.’

‘And what about me? Am I expendable too?’

The inquisitor met her gaze and replied without hesitation. ‘Yes.’

He pushed past, but then stopped and looked back at her. His expression softened slightly. ‘These are the decisions I weigh every day, Ghelsa. I need you to trust me.’

Trust was earned, as far as Ghelsa was concerned, and Harkas had done little to deserve any so far. She wasn’t even convinced his name was Ossissiru Harkas. Even so, she had chosen to help him, and was committed to that decision.

A deafening reverberation drowned out all thought. The bass vibrations rattled Ghelsa’s teeth and had Harkas wincing. It lasted several seconds, echoing back and forth across the conjoined decks until it felt as if the monstrous noise had always existed.

‘War siren,’ Ghelsa gasped when the last echoes had eventually passed.

Part warning to the crew, part challenge to the enemy, the Casus Belli’s mechanical roar signalled imminent conflict. The deckspace was lit by a red haze as power relays burst into life. Pattering feet thrummed across the interior and tributai pushed past them – work gangs dashing to their final battle stations. The heat increased dramatically as the reactor courses flushed with power, clouds of steam rising through the decks followed by bursts of coolant leaking from ancient pipes.

‘This is our chance,’ said Harkas, heading along the walkway. ‘We can get to the akropoliz while everyone else is occupied with the battle.’

Ghelsa nodded and they broke into a run, joining the flow of labourers and tech-priests moving through the innards of the Emperor Titan. Nobody gave them a second glance, and they reached the stairway up to the octuaz deck without incident.

‘Tributai!’ The mechanical bark halted Ghelsa with her foot on the bottom step. She turned and met the lensed stare of a tech-priest.

The neokora of the Machine-God was swathed in a white robe with a sash of black about the waist. No flesh was visible, the face a mask of tubes and angled metal, serrated claws nestled within voluminous sleeves. Green vapour puffed from a valve atop a cylinder jutting from the tech-priest’s back, each artificial exhalation accompanied by an acrid smell.

Out of the corner of her eye she saw Harkas flexing his arm, perhaps readying his digi-laser. She stepped in front of the inquisitor and bowed to the tech-priest, signalling behind her back for Harkas to do the same. With her eyes averted downwards, all she could see was the hem of the robe dragging on the decking, edged with frayed threads and stained from continuous contact.

‘Accompany me,’ commanded the tech-priest. The neokora turned away with no further explanation.

Ghelsa straightened and Harkas caught her eye, twitching his head towards the step to suggest that they should flee. She shook her head and he responded with a deep frown.

‘Tardiness is a weakness,’ intoned the tech-priest without looking around. The walkway was almost deserted now, all crew at their positions. A pair of epilekhtoz withdrew to make way for the tech-priest.

Grabbing Harkas’ wrist, careful not to crush bone, Ghelsa started after the machine-neokora and pulled him along with her. They followed closely, the tech-priest’s presence acting as a form of camouflage, masking them from scrutiny. The neokora led them to a conveyor near the port galleries, the latticework door wheezing open in response to a silently transmitted cipher.

Though far better than the chain-lift with which Ghelsa was much more familiar, the elevator was by no means large, its cage ceiling forcing her to hunch to avoid banging her head.

The door slammed shut and the tech-priest reached out a clawed hand to grasp a lever. It pulled the control and an engine coughed into life in the base of the conveyor.

Ghelsa’s heart sank along with the cage as it rattled back into the lower reaches of the downdecks.

Chapter 4

Striking Back

Enemy fire lashed into the Casus Belli’s shields, from the smallest flicker to sheets of explosive energy that cascaded across the hemisphere of azure power. With each blast a surge of digital information scattered across the noosphere to be analysed and archived.

Exasas monitored this activity with a mechanical detachment, but could not halt a flurry of more organic feelings emanating from the princeps senioris and the machine-spirit of the Imperator. Though the shields held against any physical damage, it seemed as though the Casus Belli waded into the fury of a raging torrent. Within the bowels of the machine, void shield generators overloaded as they took the brunt of the enemy attack, while motive engines struggled against the steepening ground. Exasas registered the strain of the immense war engine as a series of negative modifiers acting as a drag on vis cogitations.

Despite all that was thrown against them, the battle group prevailed. Plasma blasts and searing lasbeams eradicated tank squadrons and reduced super-heavy Titan-hunters to steaming slag piles. A hail of shells and rockets slammed into the walls of Az Khalak, cracking buttressed ferrocrete, tumbling support towers, buckling turrets. Since Steel Wolf’s demise, another Reaver – the Labour of Battle – and a Warlord called the Phlegmatix had been lost to the full brunt of the enemy’s power, but the Titans of the Legio Metalica pressed on without relent. The command that Az Khalak had to fall was not just a military necessity – it was seared into the souls of the god-machines, and through them the princeps and their crews.

By Exasas’ estimates, the enemy dead from this engagement alone numbered more than ten thousand, and four or five times that number would be lost by the time the citadel was breached. It was not an inconsiderable amount of casualties, but while the exchange of five Titans – two of which were recoverable – seemed quite a high price to pay, with a kill-efficiency in the region of 89 per cent, the battle could be deemed a success.

In fact, the magos’ estimates had expected the battle group’s kill-efficiency to be around the 75 per cent mark, far lower than they had achieved. With the terrain, the prepared defences and the commitment of anti-Titan war engines, as well as the orbital strikes that had rained down until the battle group had moved into range of the citadel, the fighting should have been harder. While it was possible that more casualties would be suffered by the Legio Metalica in the final conquest of Az Khalak, it seemed unlikely – the enemy had failed to concentrate their fire effectively against the Titans, and hence had been unable to inflict substantial damage on those that were still mobile.

Exasas [direct trans/Monderas]: <The enemy are presenting a dichotomy. The planning behind the combined commitment of the anti-Titan reinforcements and orbital attack shows a high degree of discipline, patience and communication. Conversely, on commencement of the counter-attack, target prioritisation and persistence of effort have been lacking. I have calculated that had the enemy desired it, they could have posed a considerable threat to the Casus Belli, but they have been distracted and diffuse in their efforts.>

Monderas [direct trans/Exasas]: <Then we are to be thankful for their lack.>

Exasas [direct trans/Monderas/emphasis modulation]: <No! We must not allow complacency to undermine our efforts. This deficiency is uncharacteristic of their battle effectiveness thus far. We have seen from their use of super-heavy vehicles that they have access to Adeptus Mechanicus facilities, and a number of the syntakharxes of Nicomedua have clearly defected to the cause of the rebellion. These hereteks conduct the same logistarius and strategos cogitation rites that we do. They will know that their defence is ineffective.>

Monderas [direct trans/Exasas]: <Since the battle began you have pondered and surmised and speculated, but you have offered no guiding course of action, nor contributed anything meaningful to the conduct of the Casus Belli. Your idleness without commitment to engagement with your skitarii has caused you to overly indulge in prognostication of matters beyond mathematical foresight.> [imperative] <You are experiencing data-paranoia, magos.>

The abruptness with which Monderas severed the link sent a flash of corrosive feedback along Exasas’ noospheric processors. Ve had hoped that vis fellow tech-priest would have been more open to discussion than the moderati, but it was impossible to ignore the conclusion that Exasas had also vexed the logistarius.

It was a sobering thought, and Exasas felt it necessary to give due credence to Monderas’ assertion. Was it possible that ve was over-analysing the data? Could such a thing actually be possible? Data-paranoia was far more prevalent among battle-priests, that was true, but more as a mark of continual combat fatigue on circuitry and cogitation routines. Exasas had been in the privileged position of command within the Imperator for several decades, and hence at a slight remove from persistent battle. Only rarely did ve need to venture from the confines of the command module, even when committing vis troops into direct conflict.

Haili [alert]: <Targeting error! An enemy Baneblade is beneath my depression extent. No firing solution.>

Rasdia [imperative]: <No firing solution for the hellstorm.>

Exasas’ interest spiked, and in response alerts threaded from vis cerebellum-implants to the squad commanders of his skitarii, increasing their readiness. If the Baneblade was able to drive within the scope of the void shields, it could cause considerable damage directly against the Casus Belli, perhaps even breaking the armour around the reactor or damaging one of the primary weapons. With a thought-broadcast ve tasked several heavy weapons squads to prepare to dismount.

Monderas [alert]: <Point defence weapons will be ineffective against a super-heavy engine, princeps senioris.>

The Casus Belli slowed. Before it was fully halted, the Imperator started to turn backwards while Rasdia tried to bring the hellstorm cannon to bear on the approaching Baneblade. Several squads of renegades in camouflaged armour advanced around the behemoth, perhaps thinking to storm one of the leg bastions. They flowed through the ruins like insects from a broken nest, but their potential bite was enough to cause the magos dominus to dedicate a sliver of cogitation to their defeat.

Exasas increased the intensity of vis alert status to ‘imminent action’. Vis sensory connectors vibrated with feedback from the limbic systems of vis skitarii warriors, allowing ver to sense their agitation though ve did not biologically share it.

Gevren: <Clearing support infantry.>

Bolters erupted into life from across the Imperator’s bastion-legs and lower body, the equivalent of several squads of troops opening fire. The volleys scythed hundreds of mass reactive rounds into the armoured traitors. Detonations cracked open protective plates and ripped the flesh within, gouging ragged lines through the packed squads.

Monderas [alert]: <Enemy Baneblade is passing void shield boundary.>

The tremor of its passage and proximity warnings shuddered through Exasas’ motor systems, as though the invasion were into vis own body. Corresponding ripples of negatives clattered through the ongoing algorithms of vis cogitating engine.

Exasas [imperative]: <Second and Fourth Platoons standing ready to depart.>

Iealona [negative]: <Do not disembark your troops, dominus. Remain on board the bastions.>

Casus Belli’s weight shifted dramatically as the princeps senioris lifted the left leg. Several unattached servitors toppled against their stations, and Exasas’ grip-claws scraped over the decking until they found purchase. The Imperator pivoted at the hip joint and the building-sized leg swung forward. With equally sudden movement, the foot descended, slamming directly on top of the Baneblade.

The turret crumpled under the initial impact and a shell within the breach of its battlecannon exploded, engulfing the foot of the Imperator with dark flame. Dozens more detonations followed from its ammunition store as Iealona pushed the Titan forward, transferring more and more weight onto the super-heavy tank. Severed tracks flailed out, their snaking ends lashing through the infantry who had survived the blasts. Exasas registered the resistance of the Baneblade’s carcass as it ground into the hard earth, though vis experience was nothing like that of the princeps senioris sharing the Casus Belli’s spirit through the MIU.

Scattered remnants of enemy squads fled the carnage, many of them cut down by fresh fusillades from the bolters. A near-physical ache worried at Exasas from vis desire to deploy vis troops, but the threat had been neutralised. In their stations aboard the bastions, the skitarii squads stood down, returning to their carriage positions with a mixture of relief and dissatisfaction.

Aggressor calculations stopped mid-process, cycling down into dormancy like a numerical sigh of disappointment.

Ghelsa disembarked into a buzz of electrical discharge and a chorus of shouting, the air alive with static that danced off her skin. The ruddy light was cut through with occasional bright flashes, and in these moments of violent illumination she saw dozens of tributai thronging the deck. Four huge void shield generators dominated the space, the groan of warp cores adding to the background noise. Flares of power leapt from venting coils to earth through spinning conductor globes.

The tech-priest stepped out of the cage and gestured to the right, signalling for them to join a work team gathered around one of the generators. Sparks flew from a broken cable in a hissing blue cascade. Ghelsa moved to the front of the cage but Harkas intercepted her.

‘Wait,’ he said, barely audible above the din. ‘We can use the elevator to reach the akropoliz.’

‘That’s an overloaded void shield generator,’ she replied, gesturing with the multi-tool. She pointed into the space between decks to more energy-wreathed chambers below. A swarm of figures laboured to keep the enormous machines operating. ‘And there are eight more down there. Only three are left. When they are all down, the trouble really begins.’

‘I had not realised the fighting had started,’ said Harkas. He moved out onto the walkway, making space for Ghelsa.

‘That’s the point of void shields, isn’t it? What did you think the war siren was for?’

Not waiting for an answer, she jogged along the metal walkway to the struggling generator crew, Harkas keeping close behind. A tech-priest had an extended mechanical tentacle attached to an input socket, its attention intent upon its work. A half-dozen tributai were trying to lift a heavy cable into place to divert more power from the plasma reactor while three more struggled with a chain pulley to reposition a buckled piece of magnetic shielding.

A sudden flash erupted from the spinning discs at the heart of the machine, throwing out coruscating red waves. A piercing inhuman shriek erupted from the tech-priest. The neokora stumbled back, articulated mechadendrites thrashing while arcs of errant power danced across metal augmentations.

Whining loudly, the tech-priest collapsed, oily smoke leaking from beneath its hood. With panicked cries, two of the tributai let go of the cable and jumped away.

Ghelsa leapt forward, stooping under the cable before it could crush the remaining labourers, taking the weight across her shoulders. Teeth gritted, she glared at Harkas.

‘Grab hold,’ she snarled. Her stare fell upon the timid duluz. ‘You as well!’

Together they manhandled the cable end into position beside the secondary socket, stepping over the tech-priest’s twitching corpse.

‘Hold it there,’ she said, stepping back to ready the multi-tool. Its jaw whirred open and she set it upon the fitting, her legs braced. At her nod, the work team thrust the cable into position and she tightened the link with three quick turns.

Almost immediately the generator’s wild growling became a more sedate buzz and the arcs of power flickered away. Ghelsa gave the connector one more turn for good measure and then touched the tip of her multi-tool to her brow badge.

‘Our thanks to the all-powerful Machine-God for providing these engines to guard us from harm.’ Without thought, she reached into a pouch at her belt, her fingers dipping into the small jar within. Her hand glistening with blessed oil, she raised it to the cable and drew the liquid across it. ‘Praise the Omnissiah.’

‘Praise the Omnissiah,’ echoed the tributai.

‘You.’ Ghelsa thrust a finger at one of the others. ‘Fetch a tech-priest. The connection needs proper consecration or it will fail again.’

The duluz scurried away, calling for one of the priesthood. Ghelsa saw Harkas heading back towards the open door of the conveyor and caught up with long strides.

‘You’ll not make it on your own, you said it yourself,’ she said.

‘I don’t have time for this,’ Harkas replied, shaking his head.

Fresh shouts and a flurry of strobing blue light announced another near-failure across the deck.

‘We’re taking a pounding,’ Ghelsa said. ‘You can’t feel it, but to lose that many generators so quickly… This is serious. I’ve not seen anything like it since Acheron Hive on Armageddon.’

‘Have you been told nothing of your mission?’

‘Enough. The battle group was deployed to destroy a traitor stronghold.’ Ghelsa shrugged. ‘No enemy war engines are expected – I’m surprised the fighting has lasted this long already, with the whole battle group deployed.’

The inquisitor rubbed at an earlobe, dried blood flaking from his fingers. ‘There was supposed to be minimal opposition. It seems the strategos were wrong.’

She looked again at the failing generators.

‘Your mission won’t count for much if the Casus Belli is destroyed.’

‘Better that than it being handed to the traitors.’

‘We’ll all die.’

Harkas shrugged, as emotionless as a half-machine servitor.

‘No, not while I can do something about it,’ Ghelsa declared.

‘Listen. To. Me.’ It seemed that Harkas barely raised his voice, but there was something in his tone that cut through the cacophony of the generators and their attendants. He fixed his disturbing stare on Ghelsa, keeping her in place more surely than if she had been welded to the decking. Though his eyes were only level with her chin, in that moment it felt as though he towered above her. ‘If I fail they will all die anyway. Or worse.’

Foreboding knotted her gut at those last two words. She knew she was not an imaginative person, but enough whispered tales abounded to paint a vivid picture of the practices of the Dark Mechanicus. She shivered at the thought of what sort of monstrosity the Casus Belli might become if taken from the light of the Machine-God.

With a last look at the tributai, she followed Harkas back into the conveyor cage. He slammed the door shut behind them and pushed the lever to the ascend position.

‘We can ride all the way to the first deck,’ he said.

Ghelsa grabbed the control lever and pulled it to the neutral position, causing the elevator to shudder to a halt among a squealing of brakes.

‘If it was that simple I would have done it already,’ she snapped, still angry that he had dismissed her objections so coldly. ‘I can’t get us past the pronaoz into the central czella. Unless you have a noospheric link, you can’t either. We will need to get off at the triaz and make our way to one of the crawlworks for the hellstorm autoloader. Once inside those, we can get to the external access hatches. There are inspection ladders from which we’ll make the jump over to the main articulation block and then up into the akropoliz.’

‘You suggest that we clamber along the ammunition feed of a cannon, so that we can climb outside onto the shoulder of the Titan, from which point we ascend to the carapace fortifications. That sounds very risky.’

‘As risky as being caught by hereteks who will shoot us on sight?’

Ghelsa thrust the ascender lever again and the motor jolted into action.

The converging fire from the traitors intensified the closer the battle group advanced towards the citadel, despite the growing casualties inflicted by the Omnissiah’s war engines. The Casus Belli took the lead, forming the tip of the ram that continued to hammer at Az Khalak, punishing salvos from its weapons like the edge of a blade slicing armour and flesh. Exasas’ calculations whirled to keep up with the flow of movement away from the path of the Imperator as companies of tanks were reduced to smouldering puddles, and platoons of traitorous skitarii were pulverised by shells from the main battery and hellstorm cannon.

The enemy did not confront the Casus Belli directly but tried to slip away, parting like water before the bow of a ship to attack the smaller Titans advancing in the Imperator’s wake. Chastened by vis earlier failures and the remonstrations of the other command officers, Exasas did not voice the doubts that continued to nag at vis calculations. Questions regarding why the enemy did not bring their full force to bear against the Emperor-class Titan went unspoken, as did speculation regarding potential reasoning behind the traitors’ earlier inexplicable manoeuvres. Exasas still could not adequately explain what had transpired since battle had been joined. The need to analyse was a tight fist around the remaining pulmonary vessels of vis circulatory system.

In frustration, Exasas improvised an antithetical protocol system, divesting verself of an entire swathe of processing ability and dedicating it to full-scale antarithm functions. Their interlocked cogitational wavelengths flowed back and forth like a sea on a shore, the thoughts of the anti-Exasas pushing back against the calculations and assumptions of the dominant magos-program, advancing and then retreating as one or the other led the race to extrapolate meaning out of the continual data input.

Even so, Exasas could make no headway and decided that full interactive protocol was required to totally encapsulate the dichotomy. Ve calved off the slave-personality almost fully, granting it 95 per cent autonomous reaction.

Exasas-primary [interrogatory]: <Casus Belli as a single unit comprises the greatest threat to the security of the citadel.>

Exasas-secondary: <Correct. The firepower sequentials of the Casus Belli are outmatched by the rest of the battle group taken as a whole, yet we present a single target with singular defensive capabilities.>

Exasas-primary [interrogation]: <We have twelve void shields protecting our weapons. The rest of the battle group has many more protecting theirs?>

Exasas-secondary: <Correct. The ability of the battle group can be degraded more swiftly by attacks on our companion-engines, but as an effort-to-consequence ratio, elimination of the Casus Belli would have been more effective.>

Exasas-primary [inquiry/tense]

Exasas-secondary: <The prime opportunity to destroy the Casus Belli occurred during the first moments of orbital attack. Had the enemy delayed longer so that the citadel guns, anti-Titan super-heavy vehicles and orbital lance strikes had all occurred concurrently, there is a seventy point six per cent chance that the Casus Belli would have suffered critical if not lethal damage.>

Exasas-primary [inquiry]: <Probability that such potential was not known to the enemy?>

Exasas-secondary: <Functionally zero. All calculations are within parameters set by standard protocols. Indeed, the traitors are better placed to know the firepower quotients at their disposal, and even if they did not have access to battle records detailing the Casus Belli’s particular defensive capabilities, they could estimate accurately from the earliest tank and infantry attacks.>

Exasas-primary [directive]: <Speculate.>

Exasas-secondary [negative]: <Insufficient parameters for speculation.>

Exasas-primary [inquiry]: <Cause for oversight of potential destruction of the Casus Belli.>

Exasas-secondary [theory]: <Deliberate strategy.>

Exasas-primary [imperative/directive]: <Focus calculation on determining potential enemy motivation within the parameters discussed.>

Exasas-secondary [affirmative]

They rumbled upwards without conversation. With nothing to distract her, Ghelsa’s thoughts returned to her predicament. Her hands started to tremble, causing the callipers of her exo-phalanges to click rapidly.

‘You weren’t very convincing earlier, when you said you’d call off the hunt for me.’

‘I will ensure your safety once I retrieve my sigil and contact the skitarii dominus.’

Ghelsa nervously tapped her metallic fingertips against the cage wall until a scowl from the inquisitor stopped her.

‘They say that an inquisitor can kill a world,’ she said, far more cheerfully than she had intended.

‘Who are “they”?’

‘Stories. Bunk chat. Is it true?’

‘It is called exterminatus. And yes, it is within the authority of an inquisitor.’

Ghelsa nodded. She felt on edge, bordering on frantic. She put her hand on the control lever, using it as an anchor, a connection to the real world when everything seemed so dream-like.

After a moment, Harkas laid his hand on the back of hers. There was blood under his fingernails and his knuckles were swollen.

‘Have you ever ordered exterminatus?’ she asked.

‘Twice.’

She studied his face for a deeper reaction, but there was nothing there. She could read more emotion in the metallic features of a tech-priest. He was so steady, so solid, that her giddiness subsided just by looking at him. It was reassuring in a way. If someone had the power to destroy a world, she wouldn’t want them to be prone to excessive emotion.

‘They could not be saved,’ Harkas continued. He took his hand away and folded his arms. ‘It was better that their corruption did not spread to other worlds.’

‘That’s why you’d prefer the Casus Belli to be destroyed rather than turned against the Imperium.’

‘I see that you are starting to gain a better perspective.’

Ghelsa realised she had lost count of the number of decks they had passed and looked at the numeral dial. They approached the pentaz. Two more to go.

They clanked past the tesseraz in silence. Harkas reached past her and pulled the handle to the braking position, bringing them to a halt as the indicator dial reached the third numeral.

‘Are you ready?’ he asked, his hand hovering over the manual door activation. Ghelsa nodded even though she didn’t feel ready at all. Staying in the elevator cage wasn’t going to improve her situation.

While the devolved persona started running its own simulations and data-mining, Exasas returned vis main focus to the ongoing battle, shunting across any relevant data as it arose. Counter-battery fire had reduced the thunder of the quake cannons to an erratic booming and proximity to Az Khalak prevented further attack from orbit. Like ants beneath the attention of one of his skitarii, streams of infantry fled through the ruins unmolested as the Titans directed their ire against the main defences. The troops that remained posed little threat to the Imperator, but the opportunity to deploy the skitarii seemed obvious to Exasas. Ve made no such request, calculating a high probability of rebuttal and further unpleasant possibility of censure.

The Casus Belli had reached the slope of the city outskirts – more accurately the main cordon wall that encompassed the outer settlement. Ragged breaches in the thick ferrocrete barrier gave ingress to streaming lines of traitors on foot, but the gates were barred, leaving scores of tanks abandoned on the roadways leading to them. Engine detonations accompanied each of the Titan’s steps as it advanced along the main highway, armoured vehicles like the shells of insects crushed beneath a careless soldier’s tread.

Iealona [imperative]: <Break the gates.>

A spur of urgency from all three moderati betrayed their competitive rivalry as each attempted to bring their weapons to bear before the others. Exasas detected power level warnings throbbing through the noosphere from the reactor, but they were quickly erased by a command protocol from the princeps senioris directing all available energy to weapons fire.

It was Haili’s plasma annihilator that discharged its rage first, targeting the western tower – a blocky hexagonal fortification studded with heavy weapon ports. Three bright stars flashed into the building in rapid succession and a trio of blast waves pulsed out, dispersing the atomised remains of the tower’s structure. The gate sagged, but held for a few more seconds until the combined fire of Gevren’s main battery, defence laser and akropoliz gun towers shredded the reinforced metal with a blinding barrage.

Rasdia’s annoyance flooded the noosphere, the target obliterated before his hellstorm cannon had built up to firing speed. With a whine audible even within the command module, the weapon powered down, its multiple barrels slowing to a stop.

Rasdia: <It’s better to conserve the ammunition for more worthy targets.>

Haili: <Yes, that was surely your considered decision and not at all an excuse for your laggardly interface.>

Iealona [rebuke]: <Show some decorum. These are the lives of the Omnissiah’s servants being taken. Though they have reneged upon their duties to Him their loss is not trivial.>

It was indeed a sobering thought, and one that Exasas pondered as the Casus Belli strode through the smoke of the gate remains. To either side the wall proved little obstacle to the Warlords, whose fists and guns broke apart wide sections to allow them to pass, tumbling the broken pieces upon the bodies of the dead as all the works of traitors would be toppled.

Exasas [direct trans/closed/Monderas/inquiry]: <What lures one into the sphere of ignorance?>

Monderas [direct trans/closed/Exasas]: <Why does one turn away from the exploration of the Omnissiah? It is to believe rather than to calculate. To revere faith alone over enlightened dedication.>

Exasas [direct trans/closed/Monderas/inquiry]: <One might muse upon the distractions of technotheological determinism, but I cannot encapsulate a theorem that would provide benefit outside the scope of the Cult Metalica. Why would one choose voluntary exile into the darkness of the unenlightened?>

Monderas [direct trans/closed/Exasas/theory]: <The transitory but addictive nature of short-term gain. The illusion of control outside the noospheric embrace of the Great Edifice of Mars Supreme. It is adolescent thinking to strive for independence, denying the interdependence of all the components of the Machina Cosma.>

Exasas [direct trans/closed/Monderas/inquiry]: <A self-applied delusion, then?>

Monderas [direct trans/closed/Exasas/theory]: <Or external interference masquerading as revelation. Also do not discount the possibility of unintended contact with corruptive noospheric sources or potential xenos infiltration.>

This caused a worry to shiver through Exasas’ cognitive processors.

Exasas [direct trans/closed/Monderas/inquiry]: <It is not my field of expertise, so I am unaware of any precedent for wholly external corruption. Is it possible to become heretek unwillingly?>

Monderas [direct trans/closed/Exasas]: <It is not a dedicated field of study for me, either. We stray into issues of definition.> [inquiry] <Is volition required for techno-heresy? If one strays under the lead of another, is one a heretek? Can the simply misinformed claim innocence of their transgressions? These answers are beyond a magos dominus and logistarius to conclude.>

Exasas [direct trans/closed/Monderas]: <While the beginnings of techno-heresy may perhaps be obscure, there can be no doubt regarding the loyalties of those that oppose us. The Machine-God is Truth. The Omnissiah is the Incarnation of Truth. To oppose the servants of the Omnissiah, to slay them, is direct contravention of the Truth. No doubt remains that once one raises arms against the Truth, one has transgressed.>

Exasas-secondary [direct trans/closed/Monderas/Exasas-primary/inquiry]: <I have been monitoring this exchange and I wish to clarify a matter. Please extrapolate on the nature of short-term benefit to the detriment of long-term objectives.>

Monderas [direct trans/closed/Exasas-primary/Exasas-secondary/interrogative]: <Identify yourself fully.>

Exasas-primary [direct trans/closed/Monderas/apologies]: <This is a cogitator partition I created to examine possible motivations for the enemy’s inefficient behaviour.>

Monderas [direct trans/closed/Exasas-primary/Exasas-secondary]: <Very well. I shall indulge the inquiry. The attainment of long-term objectives can be less appealing when inaccurately measured against short-term benefits for a course of action. One might disregard negative consequences based on false evaluations.>

Exasas-secondary [direct trans/closed/Exasas-primary/Monderas/inquiry]: <Elaborate on the basis of false evaluations.>

Monderas [direct trans/closed/Exasas-primary/Exasas-secondary]: <Over-estimation of one’s abilities or under-estimation of the obstacles ahead. Reliance on alliances not yet made. Weighting of oaths received disproportionate to the ability of the oath-taker to fulfil them. All are forms of self-delusion that can misguide calculations. In short, belief against reason.>

Exasas felt the secondary persona parse both of vis neurocomponents away from the noosphere, ending the dialogue with Monderas.

Exasas-secondary [theory]: <I have correlated this information with the actions of the traitors and propose a hypothesis. Let us reverse the logic. It is possible that the hereteks wish to sacrifice the short-term gains of destroying the Casus Belli in return for a longer-term objective.>

Exasas-primary: <That would require the sacrifice of Az Khalak.>

Exasas-secondary: <The citadel’s destruction has been a near-absolute certainty from the moment the battle group arrived. Rather than prevent its loss, the enemy are attempting to turn the situation to some future advantage.>

Vis purpose fulfilled, Exasas started to subsume the split persona but asked a last question before wholly absorbing vis data.

Exasas-primary [inquiry]: Why would the enemy wish to degrade the numbers of the battle group but not destroy an Imperator Titan?>

Exasas-secondary: <Unknown.>

The area of the downdecks was just below the antae and temple gates of the tech-priests, through which they could pass to and from the akropoliz. The smell of incense was heavy, drifting down through grates in the ceiling just above their heads. It was almost pitch black, given over almost entirely to the immense gearing and levers of the weapons mounts. Patches of ruddy light gleamed on lubricated metal, showing scattered glimpses of spinning axles and gears. The steady chugging of the autoloader beltfeed made everything tremble. Somewhere nearby, but unseen, a tech-priest chanted low ministrations to a faltering motor.

Further up the Imperator’s torso the motion of its gait was more pronounced. Ghelsa walked along the deck without problem, compensating for the movement. Harkas had a harder time of it, swaying like an infant.

‘You’ll need to leave the robe,’ Ghelsa said. She pointed to a series of handholds cut into the plasteel of a slanted stanchion. Just a few centimetres below the brace a pair of gears creaked round as the moderatus of the hellstorm cannon adjusted aim.

A yellow light sparked into dim life above their heads.

‘Cover your ears and open your mouth!’ Ghelsa obeyed her own instruction as Harkas put his hands to the side of his head without question.

The hellstorm opened fire.

Thunder resonated across the deck, filling the air with sound and flakes of rust. Even with her hands clasped tightly over her ears, Ghelsa felt the enormous pressure of the cannon’s rapid pounding. It made her teeth ache and her gut tighten.

One Omnissiah… Two Omnissiah… Three Omnissiah… she counted, blinking away the dust. Five seconds the burst lasted, as long as a lifetime amid the deafening noise.

The tumult stopped. The yellow warning light disappeared. Harkas mouthed something, but her ears were ringing too loudly to tell what he had said and the light was too dim to read his lips. She pointed at her ear and shrugged.

He shook his head and shucked off his robe. She thought he was naked at first, but his skin caught the light with a glossy sheen. He was tightly muscled, barely any fat on his body at all. As he moved she saw pockets in the flesh – small bulges on his pectorals and abdomen concealing small pieces of gear, and a slender dagger sheathed into his thigh.

‘Synskin,’ he said, his voice raised above the background throb of the autoloader. He gestured for her to approach and took her wrist, laying her hand on his arm. It felt cold and slightly plastek. ‘Hit me.’

‘What?’

He pointed to his stomach. ‘Hit me and see what happens.’

Frowning, she complied, driving her fist into his gut. At the instant of impact the secondary skin hardened. The force of the blow staggered him, but the synthetic skin protected him from any internal damage.

‘The hyperezia were hardly hurting you at all,’ she said.

‘That is not quite true.’ Harkas raised a finger to his swollen cheek and eye. ‘But they did less harm than you thought.’

‘So you probably would have fought them off if I hadn’t come along…’

‘I am glad that you did,’ he said. ‘They were instructed to kill me. Even if I had overcome them, I think I would have been apprehended again, as you warned.’

Ghelsa collapsed the multi-tool and slid it into a sheath on her belt. She reached for a grip-hole on the stanchion and pulled herself up to the first step. She looked back at the inquisitor.

‘That almost sounded like thanks.’

‘Thank you, Ghelsa vin Jaint.’ He clasped his hands to his chest and nodded. ‘So often those of us that struggle to protect the Imperium do so in the darkness, without fame or gratitude.’

With vis repeated attempts to interpret the enemy’s intentions failing, Exasas dedicated the majority of vis attention back to the wider battle. Ve synchronised with the surveyor arrays of the Casus Belli to get a sense of the situation while a sub-processing routine accumulated tertiary dataflow from the noospheric wash of the moderati. Though it was far from the perfect interaction afforded by the MIU links, this approximation provided sufficient clarity for the magos to construct artificial sense of the conflict.

The greater part of the enemy army had been destroyed or routed, leaving the ruined streets between the Titans and the citadel a near-deserted rubble wasteland. With no concern given to the preservation of civilian life or structure, the Titans had enjoyed free rein with their weapons. Whole districts had been flattened, and across nearly half of the fortified city barely a structure more than two storeys high had survived.

In places Exasas detected collapse patterns more suggestive of demolition works than warfare. Correlating these positions to the database of the city’s geography, ve discovered that many of them had been of significance to the Imperial or Adeptus Mechanicus authorities.

It was simple enough to surmise that the traitors had started deconstruction before the arrival of the Omnissiah’s punitive forces. It seemed counterproductive to put resources into destruction rather than construction, particularly in the face of likely retribution for their rebellion.

The majority of Az Khalak had been under the jurisdiction of Adeptus Terra. Administratum tithe houses and Adeptus Arbites had been knocked down, along with several Adeptus Ministorum shrines. Whether the rebels had intended to replace them with edifices of their own misguided cult would have to remain pure speculation. Other efforts to expunge the Imperial presence seemed less conclusive. Larger housing blocs and private estates had been razed, presumably due to the pro-Imperial leanings of their former occupants.

It had been a far more calculating erasure than that being enacted by the Legio Metalica. The Titans pulverised the remnants of homes and storehouses beneath their tread while their weapons unleashed laser and plasma against the buttressed wall of the keep at the city’s heart. The decision to conserve ammunition in favour of energy-based weaponry pleased Exasas on the grounds of general resource management, but a few quick equations proved it was poor for immediate kill-efficiency.

Exasas [inquiry]: <Are we expecting delay to resupply? I do not understand why we are not expending all available effort to the destruction of the enemy.>

Monderas [datalog packet]

Registering the transmission time, Exasas realised ve had been distracted by the exchange with vis secondary persona when the princeps senioris had issued a revised mission objective. Ve unpacked the command.

Iealona [imperative]: <The enemy cannot be allowed any relent. When Az Khalak has fallen we shall push into the area immediately beyond, taking the wrath of the Omnissiah into the zone known as Aza Fai Alessa. To ensure the enemy have no opportunity to stage a hardened defence or regroup, there will be no pause for resupply. The skitarii support column will detach to complete the pacification of Az Khalak and the battle group will proceed in isolation.>

It was unorthodox, both in timing and nature, but the datalog confirmed that the order had been issued via the princeps senioris’ MIU noospheric interface. Backtracking through the archive, Exasas discovered a spike of inter-moderati traffic prior to the announcement, but the details of their interactions were codelocked against examination. This was also unusual but not without precedent. Exasas tried not to interpret vis exclusion as a personal slight, but given that the communications had been sealed by Gevren’s authority it was not a possibility ve could wholly discount.

Further introspection was curtailed by a wave of surveyor alerts announcing the arrival of considerable traitor aerial assets. Deployed from deeper within the mountains, the flotilla comprised several high-altitude bomber aerostats and a large number of ground attack craft. Visual trackers locked on to the rising whale-like bombers while smaller, dart-shaped aircraft powered nearer, dangerously close to the ground to avoid surveyor detection until the last moment. Sonic warnings alerted the regular crew of the Titan while the noosphere trilled to the alert of missile locks.

Gevren’s presence loomed large within the noosphere and the Imperator’s guns barked their retort. The defence laser – an armament capable of striking orbital starships – spat forth a ruby beam that instantaneously obliterated a strategic bomber. The blast left nothing but energy residue scorched across the sensor panels.

Smaller gun turrets spat their fury at the incoming attack wings, filling the sky with shrapnel bursts and flickering lasbeams. The flare of rockets streamed in return, fanning out from the swooping attack craft. A few targeted the Casus Belli, their volleys exploding ineffectually against the massed banks of void shields. The majority were aimed at other engines of the battle group. The flare of overloading void shields surrounded the Woundwalker, a Warhound that had been circling the left flank, and the central Warlord Indomitable Guardian, while long-range lascannon shots from other ground attack aircraft scoured lightning welts across the energy defences of a Reaver, the Victorious Endeavour.

The Imperator’s anti-air batteries snarled in reply, guided by Gevren’s will. Flak detonations stitched black clouds around the incoming squadrons and rapid-firing autocannons laced the air with slashes of tracer rounds. The spiralling trails of damaged craft told of a handful of successes, but as the Imperator continued to forge up through the outskirts of the city the survivors spiralled around the colossi of the Machine-God, their guns ablaze.

Ghelsa continued up with Harkas just behind her. The crude ladder took them above a massive conduit of plasteel hanging from the structure of the shoulder works. It shook constantly as the autoloader belt within carried shells the size of battle tanks up from the magazine store in the Casus Belli’s midsection. Its course turned vertical as it passed into a sheath of articulated metal, inverting a level above them to meet the cannon mounting somewhere in the darkness of the shoulder mount. Glimpses of sunlight shone into the gloom as the building-sized weapon swung around, highlighting a profusion of metres-thick plasteel struts and artificial fibre bundles as broad as trees.

‘We cannot scale that,’ said Harkas, looking up at the sheer surface ahead. Fist-sized rivets held it together but were too far apart to be of any use.

‘We’re not going to,’ Ghelsa said, hooking her multi-tool into the lever-lock of an inspection hatch. The square of metal hinged outwards, leaving a gap large enough for a person to enter. The belt was currently empty of shells while the princeps and moderatus sought a target. The massive clasps were ideal as an improvised elevator, though they clattered past at hazardous speed.

The tributai and inquisitor stood side by side at the opening, judging the moment to leap. Ghelsa crouched, creating tension in the exo-struts implanted into her legs. The fabric of her coverall bulged with hard lines.

Harkas jumped and she followed a heartbeat later, reaching for an empty shell bracket. Harkas landed with a shout and wrapped his arm around a jutting bracket. Ghelsa thudded into the belt more heavily, knocking the air from her lungs. As she slipped down the corded fabric she threw out a hand, seizing hold of a strut.

Carried upwards, darkness swallowed them and the din of their passage drummed within the confines of the belt canopy. Ghelsa hauled herself alongside Harkas, teeth gritted, and then pushed ahead. She clambered onto one of the open bracket arms and grabbed the multi-tool, pressing a release catch so that it telescoped out to its full length. Ghelsa held it out, the hooked blade for cleaning chain links pointed towards the side of the autofeed. She turned, leaned against the corrugated belt and thrust her other hand towards Harkas. She knew from the twin circles of paleness that he could see her far better than she could see him.

‘Grab hold.’

The inquisitor did as asked, gripping her wrist, her calliper-assisted fingers curling around his arm in return.

Ghelsa hauled him alongside her and looked up, straining her eyes for a telltale sliver of sunlight that marked the boundary point between the feed and the cannon housing.

‘You know, if I miss this we’re going to get dragged into the firing breach and crushed to death.’

‘I trust you,’ said Harkas. Three words that sang in Ghelsa’s ears.

So shocked was she by this rare praise that she almost forgot to jump. At the last moment, just as the belt started to invert, she hurled herself outwards. The multi-tool clanged against the compartment wall, its sharpened claw piercing the sheet plasteel. One hand rigid around its haft, the other locked on Harkas, Ghelsa thudded into the side, jarring her shoulder and banging her head against the metal.

She looked up. A gleam of sunlight bounced from the passing shell brackets about a metre above the head of the multi-tool.

‘Use me as a ladder,’ she said, ‘and then help me up.’

With her back against the plasteel, she lifted Harkas as best she could and braced her foot so that her reinforced thigh formed a step. Harkas grabbed hold of the strut of her right shoulder through her coverall and pulled up with a grunt, his foot finding her thigh bar. She wrapped an arm around one of his legs, steadying him as he placed a foot on her other shoulder, reaching with both hands.

He stood there for a second, silhouetted against the brightness, and then vanished. A heartbeat later he reappeared, reaching down to Ghelsa. She flexed her exo-skeleton and hauled herself into his grasp. He pulled, holding her at the edge of the opening while she worked the multi-tool free. She swung a leg into the gap and half-rolled out of the ammunition chute.

Ghelsa lay on the support girder for several seconds with her eyes closed, sucking in lungfuls of crisp air. Opening her eyes revealed the underside of the immense akropoliz, and to the left the armoured bulk of the hellstorm cannon housing. She turned her head slightly and blue sky came into view.

Cold air stung her eyes and the wind caressed her face. She sat up and smiled. It was the first time in two years she had been outside.

Chapter 5

The God-Machine

From her position upon the flank of the hellstorm cannon Ghelsa had a panoramic view of the battle, but it lasted only moments. Even kneeling caused vertigo to spin through her, sending her back to her belly for several seconds. The crisp air was bitterly icy in her lungs and the openness threatened to sweep her away like a mote on the wind that streamed across the hellstorm cannon mounting.

She took a deep breath and closed her eyes, attempting to master the sensation. Instead of the startling emptiness, her senses instead focused on the alien movement. Though she was only a few metres from where she had spent most of her life inside the downdecks, the rolling sensation of the Imperator’s gait was even more pronounced on the exterior. The hellstorm swayed for several seconds after each movement, its ponderous pendular motion quite nauseating for the first few moments.

When she looked again Harkas was standing next to her, arms crossed as he surveyed the vista around them. Hesitantly she gained her feet and joined him, the sharp edge of temporary agoraphobia blunted by his presence.

The void shields that encased them distorted the view, like a heat shimmer edged with blue and grey. Ghelsa had never been outside while the energy defences were operational. The air felt oddly heavy on her skin, the hairs on her arms tingling with static. There was a distinctive clinical smell on the breeze, reminding her of the ablutions downflues after a full cleansing.

Her eyes were drawn to the fortified city around and ahead of the Casus Belli. It was closer to an artificial mountain than a settlement, tier upon tier of armoured walls and towers rising out of the foothills. Dark thunderheads swathed the peaks beyond the fortress settlement, flashes of lightning in their depths. Anti-aircraft fire streamed into a bright spring sky, tracer rounds and the blossom of airbursts chasing squadrons of Imperial bombers across the dark blue. Missiles streaked groundwards in reply, their detonations carving fiery welts into the ferrocrete walls.

The flash from concealed muzzles betrayed the presence of heavy guns in the central keep. Every few seconds a blossom of fire and shrapnel splashed across the view, accompanied by a halo of purplish light as the void shields swallowed the detonation.

‘Az Khalak, it is called,’ said Harkas, shielding his eyes against the glare of twin suns. ‘It means “The Last Defiance”, although it merely holds the pass to the mountains. It might be the largest enemy stronghold, but it is not the last. It has to fall before any meaningful attack can be launched against the traitors taking shelter in the highlands.’

Ghelsa shuffled to the edge of the platform. She was used to crawling over the service ladders and maintenance gantries during reconsecration, but she had never been outside the Imperator while it was in motion. She looked down.

Beneath them swayed the banner for the hellstorm cannon. More than four times her height, the standard was woven from red and gold, threaded with over a thousand battle honours around the iron skull symbol of the Legio Metalica.

The ground moved past with surprising speed despite the ponderous nature of the mechanical giant’s stride. An armoured torso that concealed the downdecks stretched towards the ground, shadowed by the Imperator’s akropoliz. She followed the course of an immense foot, its huge toes splayed beneath a building-like greave large enough to house half a company of soldiers. The foot threw up a cloud of dust as it settled on the hard dirt, sinking several metres into the ground. As effortlessly as if it were a living person, the Titan’s weight shifted from one hip to the other, pushing it forward.

Craters and burning war engines littered the outskirts of Az Khalak. Levelled buildings and broken defence towers spilled their shattered blocks down the slopes. The ragged remains of streets were dotted with charred tank hulls by the score, many of them little more than slagheaps in the midst of glassy furrows ripped by the annihilator and the plasma weapons of other Titans.

When dizziness threatened to topple her again she turned her attention to the Titan’s structure, something closer and more tangible. To her left the head jutted from the God-decks. She wondered if a bridge crew member might look out of the closest eye-like canopy and see two figures on the cannon like ants crawling up a skitarii soldier’s arc rifle.

Beyond the mass of the upper torso the plasma annihilator hung on the other mount, gleaming with the power of a trapped star. Vapour coiled from dozens of vents, swathing the weapon in its own cloud.

Past this mist Ghelsa saw other machines of the battle group advancing. Warhounds sped ahead, their mega-bolters and inferno cannons terrorising the infantry companies fleeing back towards the citadel. A little closer advanced a Warlord Titan – Ghelsa recognised the banners of the Will of Iron. Though a majestic, towering destroyer of the Machine-God in its own right, the Warlord was dwarfed by the Imperator.

She could not see the other Titans of the battle group, but knew there to be more. Nearly half the Legio Metalica’s current strength had been deployed to Nicomedua – a demonstration that the Omnissiah’s power had not been eclipsed even in such benighted times.

Wheeled recon vehicles preceded the Casus Belli, partly to ensure adequate footing for the behemoth and partly to clear away small pockets of resistance that were not worth the attention of the main guns or secondary batteries. These in turn were only a vanguard for the hundreds of skitarii tanks and walkers that followed in the wake of the Titan’s advance, their mission to seize the ground once the enemy had been routed.

The first support line that followed consisted of two dozen tall walkers of varying patterns and armaments painted red and black, flying a profusion of kill banners and family flags. They were the Knights of House Raven, auxilia from the world of Kolossi whose alliance dated back to the distant conquests of the Great Crusade. At the centre strode Lord Lucitas in his heraldry-decked Knight Atrapos, itself a relic of this ancient past. Upon his left and right advanced two Knights Warden with immense back banners carrying the standard and trophy icons of the house.

The bulk of the House Raven forces were Knights Paladin, split into battle-squadrons among the Metalican tech-guard. The slower but more heavily armed Knights Warden followed with the skitarii, ion shields casting shimmering shadows from the accompanying tracked troop carriers.

Gears each a storey high and more ground into motion with a rumble of huge motors. The building-sized breach chamber swung left towards its next target. Looking along the length of the hellstorm – each of its six barrels wide enough to drive a tank into – Ghelsa saw a battery of defence turrets studding a curtain wall of Az Khalak.

‘It’s going to open fire!’ she yelled, herding Harkas towards the grip-rungs that ran up the side of the main housing behind them.

The inquisitor needed no encouragement, all but flying up the ladder in his haste. Ghelsa came after him, a little more laboured, fatigued by her efforts. They gained the top of the cannon’s breach casing and dashed towards the rear, where a web of slender traverse lines gave access to the exterior of the Imperator’s uppermost superstructure. Together they leapt onto the cabling and crawled spider-like to a small observation ledge right beneath a promontory of the akropoliz.

The hellstorm boomed into life as they scaled the last leg of their climb, the fire of its muzzles lighting the underside of the carapace, illuminating ferrocrete that looked more like the bedrock of a mountain than something that belonged on a war engine.

Gasping as shockwaves pounded her against the Casus Belli’s armoured skin, Ghelsa gritted her teeth, one hand hooked around the ratlines, and grabbed Harkas as he was flung bodily against her by the pressure waves from the hellstorm’s muzzle.

He gripped her arm and they hung together like a pair of spiders whose web had been caught in a gale.

The bombing attack was timed alongside a renewed bombardment from the remaining citadel guns, which laid down a blanket of detonations around the war machines. A flow of noospheric pressure agitated Exasas as the shields of the Omnissiah’s Temper failed and the Warlord Titan took hits directly against its armoured hull. A pulse of secondary sensation coursed through the minds of all the noospherically linked when a carapace multi-launcher exploded, its remaining missiles tearing apart the mounting.

Exasas’ articulated limbs twitched in empachronicity as more shells tore chunks of armoured flesh from the Omnissiah’s engine of battle.

The Casus Belli’s defence laser stabbed out again, slicing through one of the remaining gun towers. A magazine filled with plasma-warhead shells erupted like an artificial volcano, molten metal and ferrocrete flowing like lava down the sloped streets of the inner city.

Attack craft circled, guns spitting rounds at the Titans trying to restore their void shields. No single bullet or las-bolt could pierce steel-like skin, but the continuing torrent of incoming fire was enough to overload a void shield as soon as it was brought back online.

Exasas was surprised when a third aspect to the ambush revealed itself. Sudden plasma fire erupted from infantry concealed within the rubble around the Will of Iron. Faced with this unexpected attack, the Warlord was forced to back down, its energy output devoted to recovering its shields, its gatling blaster only capable of laying down short bursts of suppressive fire until the Warrior Hammer of Nyziroz moved up in support with its own salvo of plasma blasts.

The aircraft quickly diverted from one end of the battle group to the other while the high-altitude squadrons dropped their immense payloads. This time there were no distinguishing targets. The Casus Belli, Laodoniz Vanguard, Victorious Endeavour and Omnissiah’s Temper were all caught in the conflagration as incendiary bombs covered the whole right flank of the advance. Sinews that would have gritted Exasas’ teeth tightened and a clawed appendage flexed with anxiety as slews of white-hot fire poured over the shields. Several collapsed in quick succession as though the flames burned through layers of flesh.

Overshots from the bombers detonated among the following skitarii troop carriers and walkers, incinerating them in globular expansions of brightness. The directional ion shields of accompanying knight squadrons flashed while bursts of cruel flame scoured along the line of walkers. The slick of fire seemed to crawl onwards, flowing like a swarm of burning wasps as it consumed more of the battle group’s support.

Monderas [imperative]: <That is phosphex!> [inquiry] <Where did the traitors discover such a stockpile? Inventory logs show no such weapons on Nicomedua.>

Gevren: <Many vaults once lost to the warp have been rediscovered since the awakening of the Great Rift. Forge worlds forgotten to history have re-emerged. A few thousand tonnes of phosphex warheads are probably the least of the weapons unearthed from the ancient past.>

Exasas: <It is now incontrovertible that the enemy are attempting to isolate the Casus Belli. Continual targeting of the battle group and support elements shows that the traitors wish to separate us from our companions. I strongly recommend that the princeps senioris revisits her earlier revision of the battle group’s orders in light of this.>

There was no reply from Iealona, and Exasas was forced to surmise that she was too intently involved with the battle to spare a thought for vis suggestion. It was Gevren that responded instead. His transmission was curt, interspersed with fragments of orders to the gunnery positions as they continued to target the swirling aircraft squadrons overhead. Among the chatter Exasas detected the outwave of a longer-ranged broadcast from the moderatus prime but was unable to trace its destination.

Gevren [imperative]: <We have more pressing concerns, Xaio.> [data-packet]

The scanner log thrust into Exasas’ consciousness revealed a second wave of aircraft coming from the citadel itself, their course taking them directly towards the Casus Belli.

An inferno raged around Ghelsa and Harkas as they clambered ever upwards. Curtains of white-and-blue flame rained around them, kept at bay only by the flaring void shields and the ministrations of the duluz within the downdecks. Dim shapes flitted beyond the conflagration as smaller aircraft strafed around the Casus Belli. Ghelsa imagined the incinerating heat washing over them, but the void shields kept out even the tiniest hint of warmth.

‘Praise the Machine-God for the artifices that deliver us from death,’ she declared, helping Harkas to swing over to another narrow ledge and one last set of ladders. This brought them up the flank of the akropoliz, to the crenellated edge of the outer fighting platform. They came upon a maintenance access door just below the revetment, a hatch about a metre in diameter. Ghelsa rested against the red-painted ferrocrete while Harkas tried the handle. It did not open.

‘I see no lock,’ he said, straining at the metal bar.

‘It might just be rusted a little,’ she said, motioning for him to let her have a look. She grasped the handle and turned, using all the force of her exo-skeleton. With a shriek the handle came away, shearing at the point of contact with the door.

‘Apologies, mighty Casus Belli,’ Ghelsa said quickly, laying a comforting hand on the wall beside the hatch. ‘In error I have sought by force that which I should have asked permission to do. I will make amends.’

She touched the broken handle to her brow-cog and stowed it in a pouch at her belt. She examined the door again, hoping that perhaps the handle coming away had exposed the mechanism, but it was not so.

‘It’s no use, we won’t be getting in this way.’

Harkas took something out of one of his skin pockets. Sunlight caught on a flash of metal as he cast his arm up. A thread-slender line snaked out of his hand after it and hung down the wall as whatever he had thrown attached somewhere over the battlement. Ghelsa looked dubiously at the wisp of a line.

‘It comes from a Catachan funnelthread spider,’ said the inquisitor. ‘The Catachan regiments use it to weave anti-blast vests. Believe me, if you were strong enough you could pick up a battle tank with it.’

‘And at the top?’ Ghelsa looked up but could not see what had attached to the ferrocrete.

‘Microadhesive suspensor,’ Harkas said. ‘Similar to the mag-grips used in the boots of Space Marines.’

He grabbed the thread in both hands and put a foot against the surface of the akropoliz foundations.

‘What other fancy things have you got hidden away?’

‘All manner.’ Muscles taut, Harkas started climbing, walking up the wall. ‘Just in case.’

Ghelsa found it more difficult, her exo-callipers affecting the fine motor coordination of her fingers so that it was hard to keep a grip on the thread. She had to reach up and wrap it around her hand, pull herself after Harkas and then unwind the line from her other hand. It was time-consuming and the inquisitor waited for her beneath the line of the akropoliz battlement. Ghelsa was happy to stretch across and hang by her fingers from the stone-like material, easing into a gap in the crenellations to check there was nobody around.

The expanse of the carapace was a courtyard in front of the gates and towers of the main akropoliz, inside which were located secondary batteries, a volcano cannon, the Astropathic tower and anti-aircraft weapons. Barracks for more skitarii and the temples of the tech-priests took up the rest of the high castle. Several high-arched gates and a profusion of windows and smaller doorways broke the buttressed walls and soaring towers. Scrying-servitors linked to augur systems peered down gargoyle-like from beneath the turrets and upper ramparts, scanning with dead eyes.

Harkas moved to pull himself over the lip of the wall but Ghelsa thrust out a hand to stop him. He dangled thirty metres above the ground.

‘Remember, I said I would get you this far, and then we’re finished,’ Ghelsa said.

‘I remember.’ Harkas looked at her hand on his chest, and then at her, one eyebrow raised in challenge. She withdrew her hand with a look of apology. ‘Once we are inside the akropoliz,’ he said, ‘you can find a place in which to lie low and I will track down the moderatus prime to locate my sigil.’

‘Agreed.’

A klaxon sounded just as they were about to clamber onto the courtyard, and in response the main gate of the akropoliz heaved open, spilling incense and skitarii into the open. Ghelsa froze, her heart hammering as squads of warriors fanned out, faces hidden behind breather masks. They wore segmented armour beneath coats and robes of Metalica white and carried an assortment of rifles and pistols.

With them came tech-priests, some humanoid, some scuttling on tentacle-limbs or floating across the ferrocrete on personal suspensor fields. Electricity sparking along their naked limbs, fulgurite priests moved with the throng of warriors, their voices raised in crackling prayers to the Machine-God.

Last to arrive was a creature that stood twice as tall as the skitarii, propelled into the open on four piston-like legs. Pierced stacks jutting from its robed back spewed scented exhaust fumes. Two large cannons flanked an armoured torso, above them a pair of mechanical arms that ended in a variety of drills, graspers and connection plugs. Its insect-like face swept left and right on an articulated neck, surveying the scene, multifaceted eyes glinting in the sunlight and the glare of energy cells.

‘That is the magos dominus!’ exclaimed Harkas. ‘Xaiozanus Exasas, the Bellicosis Majoris.’

‘He’s the one you said was loyal, that you were going to speak to.’ Ghelsa smiled, scarcely believing their good fortune. ‘He’s right there! Go on!’

‘I cannot,’ replied Harkas. He pursed his lips in frustration. ‘As you pointed out earlier, I have no evidence of the conspiracy. My only hope is to invoke my Inquisitorial authority, and for that I will need to present my sigil as proof of my position.’

Ghelsa frowned, not quite sure she understood the objection. Before she could voice her opinion on the matter, Harkas continued.

‘Also, I believe the dominus may have other concerns at present.’ He pointed past Ghelsa.

She turned her head. Angular shapes rapidly approached against the clouds of smoke that billowed up from the fire-bombing. As they swept closer Ghelsa could make out dragon-like bodies with mechanical wings, creatures that were a disturbing mix of organic and artificial. She was no stranger to the more bizarre artifices of the Cult Metalica, but the eyes of these beasts burned with an otherworldly glimmer and left unnatural vortices in their wake. She fancied she heard vicious screeches, though it was likely impossible over the noise of the Imperator’s progress and her own hammering pulse.

With them came a sight even more alarming – gunships of archaic design, painted in a bright livery of pink and black, decorated in garish stripes and patterns.

‘Space Marines of the Traitor Legions,’ whispered Harkas. ‘A boarding attack!’

Enclosed within the armoured layers of vis warskin, Exasas-tactical turned wide-spectrum lenses towards the incoming assault craft. Ve could not codify a single pattern among them – each had been heavily modified. The half-mechanical creatures that accompanied them defied any sort of analysis, and vis weapons appendages oscillated slightly at the thought of warp-corruption.

Vis mind raced with specific datastreams, analysing the likely landing sites and attack stratagems the enemy would employ. As the warskin encased vis material form, so the Exasas-tactical persona shielded vis thoughts against the anxieties of strategic calculation. The magos dominus fixated on vis immediate mission – to repel the incoming attack.

Through the billow of cleansing incense that spilled from the open gateway of the akropoliz, the skitarii corps raced to their positions, their alphas directing them to the best firing points to meet the incoming flyers. A handful of battle-priests spurted streams of binaric to one another as they helped muster the defence, but Exasas-tactical voiced vis orders through every medium equally, addressing vis troopers via audible sound waves even as vis thoughts pressed into the minds of vis noospherically cogent companions.

‘Now is the plan of the enemy revealed. While the guns of the traitors seek to fell our companion-engines, the enemy think they can gouge out the insides of Casus Belli with this attack. We will meet them head-on and repulse the landing.’

As ve spoke, the magos dominus readied the weapons protruding from the clavicular mounts of the warskin. Vis twinned serpenta grunted into life, followed by the crack of the first phosphor rounds entering their firing chambers. Using dorsal manipulators, ve fed the beltfeed from a thoracic ammunition cavity into the mounted mascrostubber. A powerfield gleamed blue against vis serrated plates as Exasas-tactical activated the relays of the long blades that jutted from vis abdominal plates.

Above, more squads mounted their weapons on the ramparts of the defensive galleries, heavy culverins and arquebuses directed towards the enemy. Guided by the will of Gevren in the command module below them, the anti-aircraft batteries blazed, surrounding the oncoming craft with fire and smoke. One of the alphas suborned the noospheric connection.

Alpha Hakreda: <Counter-air fire is ineffective, dominus. The blasts are not penetrating the armour of the gunships. Submit that the moderatus prime concentrates anti-armour weapons instead.>

Exasas-tactical passed on the request, sliding back into the noosphere for Gevren’s attention. A quick assessment demonstrated that any change in the fire patterns was not likely to have a significant effect before the enemy were able to deploy their troops, if the moderatus prime even considered the suggestion.

‘Stand by to repel boarding parties. Direct coordinated salvos and then retreat – they will attempt to use frag launchers and landing jets to clear the ramparts.’

The white-coated squads lining the outer wall raised their weapons, awaiting the command from their alphas. Sparks flared along the wings of the incoming gunships, and the drake-like monstrosities accompanying them opened their fanged jaws, revealing whirling energies within their gullets. Arcane lightning spat from the mouths of the half-mechanical beasts as rockets seared from the gunships towards the waiting skitarii. Sorcerous blasts shrieked across the armour of the tech-guard, cooking their flesh. Even as the warp-blasts scythed through them the skitarii remained stoically at their positions, their resolve bolstered by the imperatives Exasas projected across the noosphere.

Point defence guns opened fire, quad-mounted heavy stubbers that blazed thousands of rounds at the incoming attack. Black detonations marked the sky as they intercepted a handful of rockets. The detonations of those that passed through the fusillade erupted along the wall, tearing apart Exasas-tactical’s warriors with a storm of shrapnel and razor-sharp metal fragments.

Exasas-tactical impelled the survivors with the attack imperative. They blazed with arc rifles, radium carbines and plasma calivers in ongoing volleys of multicoloured fury. The dragon-engines screeched and veered away, driven back by the weight of fire, but the blocky gunships ploughed through even as plasma blasts and scintillating beams scoured across their hulls and canopies.

Scanning the gunships with a variety of visual and others senses, Exasas-tactical detected several patterns of bolter weapons and other anti-personnel armaments. They would be in range of the Imperator’s akropoliz in a few seconds.

‘Fall back.’

With the verbal command Exasas-tactical broadcast the withdrawal order. The alphas responded instantly, each a tactical vector that disseminated the magos dominus’ needs into their squads. As a wave of white, the skitarii turned and ran. Just a second later, the gunships raked fire across the parapet where the defenders had been. A few skitarii that had been slowed by flesh wounds were caught in the onslaught. Bolts detonated inside their bodies, hurling out chunks of flesh, broken cybernetics and tatters of white fabric.

Ghelsa stifled a cry as yet another gunship circled overhead, spilling armoured warriors onto the upper parapets. The reek of charred flesh carried on the wind, rank in her nostrils, as the acrid smoke of the warpflame stung her eyes. The bark of weapons turrets had lessened, the gunners overcome as more traitor legionaries made breaches into the akropoliz.

The magos dominus led a counter-attack, scything down the power-armoured renegades with a volley of phosphor fire. The skitarii concentrated the pulses of their arc rifles against the superhuman troopers, driving them back from the main gates.

‘This is our only chance,’ said Harkas. He hauled himself through the crenellations and rolled down to the courtyard.

Ghelsa found herself alone, holding onto the rampart while gunships and warp-dragons blazed with shells and rockets around her. It must have been barely a minute since the first attack wave had screamed down onto the akropoliz, but it felt like hours, so intense was the experience.

Panting, she pulled herself after Harkas, dropping down to the ferrocrete flags beside him. Explosions hurled chunks of the akropoliz wall across the open space, a plume of dust billowing over skitarii and Space Marines alike. The inquisitor dashed into the miasma and Ghelsa chased his half-seen outline, illuminated by an occasional flash of light as a bolt round sparked past or a radium blast slashed through the smog.

Others also retreated, many of them wounded or helping those that had been, their withdrawal covered by a constant pulse of weapons fire from squads positioned at the gates and firing ports on the upper levels. Anonymous among the wave of soldiers pressing back through the main portal, Ghelsa and Harkas slipped into the akropoliz.

‘Ready your ground,’ commanded Exasas-tactical. Ve delineated a defensive line across the vision of vis skitarii while the alphas re-established their squad connections and assimilated the survivors of formations whose tech-priests and alphas had been slain. Like a self-repair diagnostic, the magos dominus’ host reorganised itself into the positions decreed, while Exasas-tactical calibrated vis heavy weapons and aimed at the closest gunship.

Plasma jets flared as the craft burned off speed, slewing sideways to allow fuselage-mounted weaponry to rip fresh volleys against the upper towers of the akropoliz. Rapid-firing autocannons coughed shell after shell into the carapace fortification while the transports peeled away behind the tempest of fire.

Two dipped towards the rampart, their prows opening like the maws of monstrous raptors. Four more banked into the upper levels, spewing a stream of gaudily armoured Space Marines. The bright flare of jump packs flashed across Exasas-tactical’s visual sensors, slowing the descent of the Heretic Astartes as they plunged towards the akropoliz. Ve impulsed fresh commands to the platoon guarding the gunnery areas, sending them to the gateways and firing ports to unleash a hail of phosphor rounds and radium beams.

The two assault craft at the level of the magos touched down just inside the parapet. Even as the billowing heat wash and dust of their landing flowed over the defenders, more gene-enhanced warriors charged down their assault ramps. Among the roar of bolters came the discordant whine of sonic weapons building to lethal harmonies.

‘Eliminate.’

The simple command leapt from Exasas-tactical’s cogitation to the assembled skitarii. A wall of fire crashed across the rampart to meet the onrushing Traitor Space Marines. Exasas-tactical opened fire along with vis soldiers, spewing a long burst from the phosphor blasters and a fusillade of large-calibre bullets.

Jets snarling, the gunships rose again, freeing their weapons to provide support fire for their disgorged cargo. Traitors with brightly patterned armour wielding the archaic sonic weapons strode to the fore, strumming and triggering their armaments. Artificial squeals and rising shrieks carved erratic vortices through the smog of battle, and where these disharmonic emissions passed over a skitarii they tore apart armour, stripped flesh to the bone and pulverised organs. Caught in overlapping soundwaves, the flayed corpses seemed to dance in death, until their skeletons shattered into thousands of deadly shards.

More conventional bolt rounds accompanied the sonic onslaught, the flicker of propellant dimmed by the smoke, almost lost among the actinic flare of arc rifles.

Exasas-tactical [imperative]: <Close-quarters counter-attack.>

The noospheric signal connected to the cadre of tech-priests dedicated to short-range assaults. Electro-priests leapt forward from the ranks of the skitarii to meet the first warriors of the attacking force. Fulgurite devotees lashed with their electrified staves, their bodies flaring with energy discharges as the Space Marines swung chainswords and knives in return. Arcs of power leapt from the thoracic generators of the corpuscarii, their whole bodies lighting like active circuits as they hurled blasts of raw electricity into the Heretic Astartes.

Exasas-tactical joined the counter-offensive even as ve transmitted the withdrawal order to the skitarii platoons. Having discharged their prepared volleys, the tech-guard were best employed defending the portals of the akropoliz itself rather than becoming entangled in a sprawling melee for which they were not suited.

A Space Marine that Exasas-tactical identified as a squad leader charged at the magos dominus with a power axe upraised. Exasas-tactical expended a small portion of energy to fuel vis arc repulsor – a device of vis own invention completed to confirm vis elevation to the rank of magos. The arc repulsor belched forth of a wave of bluish force that flowed towards the traitor sergeant. At the moment of contact the diffused energy wave contracted, imploding upon itself to deliver a hammer blow impact that threw the Space Marine back, chest plastron and abdominal armour shattered open.

Exasas-tactical stalked forward and stood over the fallen foe to drive vis powered blade into the sergeant’s exposed midriff, parting secondary heart and all three lungs with a single blow. Vis heavy weapons rasped fresh volleys into the squad that leapt forward to avenge their leader, muzzle flare and phosphor lighting them like crazed lumen globes.

Even the fulgurites and corpuscarii could not hope to overcome several dozen Space Marines, but their sacrifice earned the rest of the force sufficient time to retreat to the akropoliz. Exasas-tactical decapitated another Heretic Astartes that thought ve would be unprepared for a flank attack, not comprehending that the magos dominus had perfect three-hundred-and-sixty-degree awareness and response.

Propelled backwards by long legs, weapons spitting rounds at the pursuing enemy, Exasas-tactical retreated into the main fortification. A single noospheric pulse brought the gates crashing down, sealing the portal.

Seconds later the first hiss of melta-cutters and the clang of power fists signalled the Space Marines’ attempts to breach.

Chapter 6

Repel Boarders

Inside, air filtration systems snarled in protest at the debris choking their fans. Alphas shouted and tech-priests moved among their soldiers, issuing bursts of harsh binaric while they replenished ammunition and distributed new weapons.

A huge shape loomed through the main portal, the wavering shadow becoming the dominus, surrounded by a platoon of skitarii and the crackling forms of a few surviving electro-priests. The doors boomed shut behind them and the crash of locking bars echoed dully through the interior of the carapace citadel.

As Ghelsa might strip off her coverall, the skitarii commander shed vis battle-form, the quadruped war machine peeling apart to disgorge a human-sized mechanical caterpillar. On a score of many-jointed limbs, Magos Exasas sped into the akropoliz followed by a coterie of tech-priests.

A powerful detonation shook the gate while squads of skitarii took up positions to defend the hallway just within. From inside the akropoliz, somewhere above them, gunfire and panicked shouts echoed down the corridors. A tortured screaming continued, every pain-wracked screech a fresh scratch on Ghelsa’s frayed nerves.

A hand around Ghelsa’s arm led her down one of the passageways. The walls of the akropoliz were decorated with carved friezes of scenes from Metalica – vistas of temple-factories and holy laboratories that Ghelsa had never seen. She let her fingers trace the contours of a spired manusanctuary, the tiny shapes of dozens of heavy battle tanks issuing from its arched gateways, a cog-like halo of the Omnissiah above the citadel-shrine.

Harkas moved some distance ahead and waited at a junction for her. She pushed away from the wall, but dizziness threatened to topple her and she slumped back against the sculpted alabaster. She made no attempt to resist as Harkas came back to guide her to a secluded alcove beside a low doorway into one of the secondary gunnery chambers. The steady thud-thud-thud of a defensive cannon sounded through the wall. She leaned back, placing her head against the plastek divide, finding comfort in the predictable rhythm of the gunfire.

Harkas headed back to the main hall and reappeared a few seconds later dragging a dead skitarii soldier. He took off the armour, weapons and coat for himself. The inquisitor was talking to her, but all she could hear was the rush of blood in her ears. She looked up, trying to focus on the blue light of a lumen globe behind a mesh in the ceiling. Her vision swam, bleeding into swirls and then straightening again.

‘Focus on me.’

Harkas’ voice penetrated the noise of her pulse but his face seemed to swim in a fog. He became more insistent, his grip tightening on the back of her hand, fingers pressing between the metal callipers. ‘Ghelsa, focus on me.’

Her heart was a drum in her chest, each beat like thunder. In her gut something writhed, constricting about her intestines, worming its way into her lungs to steal her breath.

‘Ghelsa!’

The word was sharp, not loud, pricking the bubble of numbness that enveloped her. The tributai forced herself to look at him through the sick feeling rising in her chest. His voice remained muted, his face sketched in drab colours.

‘Your body is going into shock. You have to stay calm’

‘I… I…’ More words spilled out, but Ghelsa did not recognise what she said.

Cooler air swept into the corridor, clearing some of the odour of sweat, lubricant and cloying incense that was the signature smell of the tech-priests. Almost immediately Ghelsa’s vision sharpened, and she was able to stagger a few steps before she had to slump against a plasteel brace.

She slid down until she sat with her back against the wall. Ghelsa stared at her hands, willing the bright metal to come into focus against the dark skin.

‘I’m sorry,’ she muttered. ‘Sorry. So sorry.’

‘You cannot be held responsible for biology,’ said Harkas. He stepped back, checking the corridor. Ghelsa was dimly aware of feet on the hard floor, lots of running. A nagging sound of impacts trembled from the gate chamber.

Harkas crouched beside her, his gleaming eyes staring directly into hers, almost blinding with their intensity. The inquisitor reached inside his robe and then pressed his hand to her neck. She felt a scratch, short but painful, and pulled away.

‘What did you just do?’ she demanded.

He held up a microdermic between thumb and forefinger.

‘A stimm, that is all. To keep you going.’

Shedding vis warskin, Exasas shifted his perspective back to a strategic mode. The magos dominus inhaled a deep draught from vis incense circulators to cleanse the taint of the outside air from vis systems, and vis calculation patterns extended into a more nebulous realm, collating data from across the whole noosphere to construct a neuroschematic of the battle for the akropoliz. Although ve could comprehend the full extent of the conflict, vis dataflow lacked the precision and clarity of vis tactical self. In particular ve was in no position to directly coordinate and respond with vis skitarii. The local defence of the Imperator was entrusted to the lower-ranking battle-priests and alphas while Exasas concentrated on the matters of broader import.

Locating three points of attack in the upper levels of the atrium, Exasas examined the progress of the Space Marines across the layout of the akropoliz. Accounting for their ignorance of the Imperator’s specific arrangement of chambers and passages, ve adjusted vis simulation and determined a likely convergence point for the trio of invading forces.

The intersection appeared in vis datathread as a glowing white rune close to the floor of the atrium where the akropoliz met with the command module access and the duluz-manned decks of the main mechanical systems.

As ve manipulated this internal display, Exasas navigated the actual corridors, passing along frieze-lined passageways and heavy-lintelled archways beyond which the gun crews continued their labours alongside the slave servitors.

Ve moved away from the fighting. Bereft of vis warskin, ve had no intention of contact with the enemy, instead racing for the atrium to best organise the defence around the enemy’s ultimate objective. Like the Az Khalak defenders, ve knew ve could not prevent vis foes from pushing through to their objective. Their bodies had been genetically engineered for close-quarters fighting and the wargear designed to enhance those already considerable abilities – by no lesser creator than the Omnissiah.

Such skitarii squads and tech-priests that Exasas directed into their path were intended as a brake on the speed of their advance rather than with any hope of halting it. Where possible they might degrade the Space Marines’ threat potential through the process of inflicting accumulating damage and, more likely, requiring enemy ammunition to be expended in their destruction.

Racing serpent-like down a spiral stair near the rear of the akropoliz, Exasas examined the attackers’ potential goals. Ve began with the general conjecture of inflicting casualties and disrupting the guns of the Casus Belli, but dismissed it on the grounds that, like the earlier attacks, if that had been the desire then the enemy should have launched the assault to conjoin with other offensives.

Having eliminated this broad possibility, ve was left with the thought that if the Space Marine attack was not general, it had to be specific. There had to be something significant about an aerial insertion into the akropoliz at that particular time.

While ve tried to unsplice the competing motivations that crowded into vis thoughts, Exasas sent a full mobilisation command to the rest of the skitarii company, ordering the alphas to arm their squads as a preparatory measure for defensive fighting inside the atrium. Ve then issued a summon-muster imperative for the atrium itself, setting into motion a series of commands that would have the skitarii in the akropoliz and those in the leg bastions conjoined at the point of greatest defence. To facilitate the more rapid passage of those within the leg bastions, Exasas subordered a request into the conveyor systems of the main torso levels, equipping vis alphas with an override to commandeer all elevators and conveyors in order to speed them to the atrium.

Ve reached the atrium three levels from its base. It was in rough outline an inverted ziggurat with four stairways running around the walls in a helical arrangement, interspersed with access arches and intermedial galleries. A delve into the atrium cartographical data highlighted two possible objectives for the Space Marines – the command module and a direct access linkway to the reactor decks. Penetration of either would prove fatal to the Casus Belli.

Ghelsa stood up and reeled away, disgusted by what Harkas had done, flailing a hand at his face when he attempted to grab her.

‘You don’t do that!’ she snarled, stumbling into the opposite wall. The giddiness dissipated but her heart raced and her skin itched. A surge of energy swelled through her muscles, pushing out the aching tiredness. But something was wrong. She couldn’t catch her breath. Her fingers and toes burned and her jaw hurt. ‘What was it?’ she demanded.

‘A standard-issue skitarii stimulant mix,’ Harkas replied.

The inquisitor’s voice sounded tinny and distant. He tossed the microdermic away and pulled a pistol from his commandeered armour. ‘I took it off one of the bodies. Nothing unusual.’

Sweat sheened Ghelsa’s skin and soaked her coveralls, running in rivulets down her back.

‘I already have additives… in my blood,’ she gasped. Hormonal surges frothed inside her veins, making her want to shout and run and pound her fists into Harkas. ‘For my exo-skeleton. I’m suffering… an… alchemical reaction. I’m burning up!’

A loud crash and renewed flurry of gunfire from further into the akropoliz made Ghelsa flinch. Pulses of las-fire and radium blasts flashed against the walls from unseen combatants. The light was too bright, the faintest noises reverberating through her skull. Her body strained against her will, demanding to move, to be set free, as if it might burst out of her skin with a life of its own. The contact points where her exo-skeleton delved into flesh and connected to bone throbbed painfully.

An explosion at the far end of the corridor tossed a handful of skitarii corpses into view, wreathed in flame, robes tattered, their blood spattering the passageway. The shadow of a giant appeared against the wall, cast by dancing firelight.

Ghelsa was running before she even knew what she was doing, the multi-tool as light as air in her hand. She barely heard Harkas’ shout, much less understood the words. All she knew was that she had to act. The fire that burned in her chest would consume her if she did not release its energy.

She leapt over the steaming corpses of the skitarii, skidding through puddles of blood into the next passageway. The floor was hard and reassuring under her bare feet, the endlessly recycled air a taste of her home, even tainted as it was by the odour of the tech-priests.

Her thoughts were a blur, racing from one subject to the next, never staying in one place, a welter of animistic impressions and instinct, nothing rational or considered.

Ahead a power-armoured figure stalked the corridor, its back turned to Ghelsa. The tributai was usually the tallest in any company she kept, but the Space Marine was larger still, his augmented bulk further swollen by corruptive power. His warplate was much adulterated, fixed with curved ornamental blades, and a pair of horns spiralled from his helm. It was a dark pink with tiger-like black stripes, hung with charms and fetishes made out of human and xenos parts. Ghelsa could not focus on the runes daubed across the massive shoulder guards.

The Space Marine started to turn, the muzzle of the bolter in his grip fashioned in the shape of a snarling dog. Spurred by the unnatural chemicals coursing through her blood vessels, Ghelsa hurled herself at the monstrous warrior, swinging the multi-tool at the side of his head.

The plasteel connected hard, the thud of the impact rebounding from the walls. Vibrations thrummed through her fingers, weakening her grip so that the multi-tool tumbled from her grasp even as she collided with the warrior’s armoured body. Staggering back, she looked up and saw that what she had taken for a helm was in fact the traitor’s head, curling horns included. His face was pale but heavily tattooed with red and green, so that he had the appearance of a creature made of some strange fire. A scratch leaked a single droplet of blood where she had struck.

Ghelsa snatched up the plasteel tool and hit the Space Marine again, aiming for the chin. A slight movement of his head meant the warrior caught the blow on his cheek, with as much affect as her first attack. The Space Marine smiled, displaying teeth filed to razor points, each studded with a black gemstone.

Ghelsa screamed and swung the multi-tool again and again, battering at the warrior’s face and head. For several seconds he made no effort to defend himself, his chest rumbling with a deep laugh while she raised welts from his inhuman flesh.

And then he moved his arm, faster than Ghelsa could follow. Pain flared through her body and her back hit a wall, the multi-tool spinning from her grip again.

The legionary took a step towards her, his dark tongue licking flecks of blood from swollen lips.

‘I am going to enjoy breaking you,’ he declared, his words softly spoken, his tone complimentary and engaging. ‘The tech-priests have built your body nice and strong, so it will take some time. That is good. It is the endurance of your spirit that I truly wish to test. We can share the ecstasy of that time. I will let you hurt me too, if you want.’

Clattering down the white-painted steps, Exasas detected the first skitarii squads emerging from the interstitial decks of the torso. Others arrived from within the akropoliz, the leading squads of Space Marines close behind. An intense firefight screamed into life above the magos as ve alighted upon the floor of the atrium and looked up. Through the eyes of vis soldiers and vis own sensory arrays ve picked out a combat-squad of Heretic Astartes – five warriors – on the brink of entering the atrium’s upper level. Channelling dataflow across the noosphere from other battle-priests stationed around the akropoliz, ve was able to devise a holding pattern of squads to limit the support from other attacking forces.

While the skitarii moved into position to close in on the Space Marines from several directions, Exasas sent two more muster commands. The first went to the auxilia tasked with close defence of the akropoliz. If Exasas and vis skitarii were the Casus Belli’s innate immune system, the auxilia would be considered the adaptive immune system, instigated after the wars against the orks on Armageddon. They were not integrated into the noosphere nor Exasas’ strategic systems, instead relying upon their natural warrior instincts and personal initiative, as guided by their officer corps. As a second layer of protection against invasion of the Imperator they had proved effective on several previous occasions, and Exasas’ victory estimates were therefore significantly higher once they were deployed.

The second corps ve activated was another standard precautionary measure, the order passed to the tech-priests of the small cybernetika cohort that usually lay dormant within the sub-layers of the akropoliz. Whether their arrival could be expedited to influence the outcome of the unfolding conflict was uncertain, and Exasas refused to add any positive bias to vis victory thresholds on their account.

Despite Exasas’ complementary manoeuvres, a number of the Heretic Astartes had moved into attack position around the uppermost level of the atrium. With a declining victory estimate colouring vis mood, Exasas registered the increasing casualty levels of the skitarii attempting to prevent the Space Marines gaining access to the main chamber.

The losses were too many to sustain. With a sensation not unlike a pang of regret, Exasas transmitted a further withdrawal code, essentially abandoning the upper levels of the akropoliz to the invaders. If ve had miscalculated the intent of the traitors – a 4.6 per cent probability to vis mind – ve had just given them free rein to unleash carnage on the gunnery stations.

Several torturous seconds passed during which the skitarii regrouped within the atrium, resetting their cordon lines and siting their heaviest weapons to cover the upper entrances. Arcs of fire and trajectory lines criss-crossed Exasas’ view as ve regarded the highest level, every white-coated warrior lining the stairs and galleries picked out with a tiny red rune that identified squad and platoon. A rapid noospheric roll call counted the losses at some third of the total skitarii force available to ver, though more were arriving as the bastion chambers emptied of soldiers.

Though relief was a strange response to imminent enemy attack, it was the closest emotional equivalent to Exasas’ reaction when the Heretic Astartes launched their assault on the atrium. In four coordinated attacks, they stormed along the corridors leading to the highest level from each direction, intent upon breaking into the broad hall.

The probability of direct contact – and concomitant personal risk – increased to nearly 90 per cent. Any momentary considerations of self-preservation were subsumed into a swell of satisfaction that vis predictions had been proven correct.

A flare of red scored a line across the Space Marine’s nose and brow. Ghelsa remembered Harkas’ digi-laser. Another flashing beam seared paint from a gauntlet raised to protect the warrior’s face.

The bark of the Space Marine’s bolter was ridiculously loud in the confines of the akropoliz passageway, and Ghelsa shrieked. All she saw was a flicker of propellant, and then she heard a pained shout from Harkas. She struggled to her feet, stimulant chemicals still coursing through her, overriding any fear. Ghelsa threw a punch, her reinforced knuckles connecting with the giant’s chin, her full weight behind the blow.

The metal of her callipers buckled and the Space Marine rocked back a step. Pain flared in her arm and her first thought was that she had shattered her wrist.

The Space Marine’s eyelids fluttered and he pursed his lips, sighing his pleasure.

With a crash, a vent cover in the ceiling fell on top of the traitor, its corner gouging a bloodied furrow across the side of the Space Marine’s head.

A wiry figure followed it, wrapping his legs about the warrior’s neck, a glowing knife in one hand and a stub pistol in the other. The Space Marine staggered as a second attacker dropped through the opening and the first opened fire, a bullet punching into the monstrous warrior’s eyeball.

The Space Marine roared, the pain no longer welcome. An armoured hand closed about the arm of the first attacker, who let out a shout of pain and dropped his pistol. He started to saw at the Space Marine’s wrist with his blade. Ghelsa pushed herself towards the multi-tool as blood sprayed, the second assailant straddling a pauldron as she rammed a broad-bladed knife repeatedly into the Space Marine’s throat.

Like a felled tree, the traitor legionary toppled, twisting as he fell. The killers sprang away to avoid being crushed beneath the weight of warplate, landing deftly as the Space Marine crashed to the floor.

They set upon the giant, firing several more shots directly into the eyes and mouth to be sure. Ghelsa recovered her improvised weapon, the claw-head thick with clotted Space Marine blood. The bout of violence had purged much of the stimm from her body, but she still felt on edge. She took a moment to take a better look at her saviours.

By their size she had thought they were adolescents, but now that she looked at them properly she saw they were simply adults who were short and lean, much like Harkas. They were both pale-skinned, with spiderweb tattoos across the left side of their virtually bloodless faces. They wore tight-fitting dark grey trousers and short-sleeved shirts of the same colour, their exposed arms covered in more black inkwork. Each had the Metalica silver cog implanted as a badge on the back of their shaven heads.

‘The xenagia…’ she breathed. ‘You’re vent-fighters from Armageddon.’

‘The name’s Dazi,’ said the woman. She flicked her bloody knife towards the other. ‘This is my choice-kin, Aszad.’

‘I’m so happy to see you,’ said Ghelsa, and then with a gasp remembered the Space Marine firing his bolter.

Harkas was sprawled at the junction and panic made her heart skip. Dashing to where he lay, she knelt down beside the inquisitor, searching for any injury. The left side of his body from ribs to hip was discoloured, reddened and bruised, but the skin was miraculously unbroken. The inside of his left arm was similarly marked where the blast of the bolt round had caught it.

She hesitantly touched a hand to the injury.

Harkas groaned. Ghelsa let out a choked cry of relief and sat back, light-headed from stress and stimm. The inquisitor pushed himself up with a wince and leaned on one arm.

‘The synskin is also a ballistic defence,’ he said, looking down at where the bolt had hit him. ‘Though I feel like I have been trampled by a grox.’

‘Praise the Omnissiah for the gift of His artifice,’ said Ghelsa, touching fingers to her cog rune. ‘In His eternal knowledge are we shrouded from harm.’

She helped Harkas to his feet, noting a few scratches on his face, the blood bright red against his light brown skin. The zip of las-fire and deeper bark of bolters resonated through the passageways still, injecting fresh urgency into Ghelsa’s thoughts.

‘Who are they?’ asked the inquisitor, looking past her to the vent-runners.

‘Xenagia. They’re auxiliaries from Armageddon. Dazi and Aszad.’ His blank look betrayed his ignorance and she continued as they walked towards the newcomers. ‘You sneaked aboard the Casus Belli and you don’t even know about the vent rats? They fought on Armageddon against the orks. Downhivers, used to living in darkness and cramped spaces. The Legio recruited several hundred of them to help defend the Imperators.’

‘We need to go,’ said Aszad, jabbing a thumb over his shoulder. ‘There’s breaches all over the akropoliz. You’re safe now.’

‘Wait!’ called Ghelsa, picking up her multi-tool as she approached the Space Marine’s corpse. ‘We need to get down to the holy decks. It’s really important.’

Dazi grimaced, displaying grimy, uneven teeth.

‘We have to fight,’ she said. ‘If the akropoliz falls we are all dead.’

Ghelsa darted a pointed look at her companion. ‘I don’t think I can lie low, can I?’ she said. ‘And how are you going to get through the akropoliz with a battle going on?’

Harkas looked at the duct-fighters with narrowed eyes. ‘Could you get me to the command module without being seen?’ he asked.

‘Why would you want such a thing?’ asked Aszad.

‘Of course we can,’ said Dazi. The two Armageddon natives glared at each other.

A rapid series of explosions rocked the akropoliz from within, showering them with dust from the open vent.

Aszad cocked his head to one side and held up a hand to stop the others from talking. Gunfire rang along the passage and echoed within the vent above.

‘I think we are going to the same place. That was at the antae.’

‘The traitors are trying to break into the holy decks,’ said Ghelsa, motioning to Harkas. ‘We have to help stop them.’

His look conveyed his opinion that they didn’t have to do anything, but he waved a hand towards the Armageddon fighters as though giving permission.

‘You are a big one, for sure,’ said Aszad, sizing up Ghelsa. ‘No vent-running for you. We’ll need to take the stairs.’

Answering to Exasas’ summons, the magos dominus’ warskin arrived at the lowest level of the atrium from one of the nearby archways. With everything set in motion to contest the entrance to the lower decks, there was nothing else for Exasas to do. Vis cogitations were far better exercised in more direct intervention.

The spider-like secondary body peeled open, combat blades and heavy weapons splaying to allow ingress as the battle augmentation awaited its controller.

Exasas coiled about verself as ve entered the central void. Armoured plates slid into position even as cerebral connectors and motive detectors pierced the sockets that studded vis smaller form. The magos felt the increased mass like a blessing of the Machine-God upon vis soul, spiritually as well as physically elevated as the warskin straightened its four legs.

Even as the hardened carapace enveloped vis form, Exasas-tactical’s more militant, aggressive codeware took command of vis mental functions. Gone were hypothesis and introspection, two traits that ran directly counter to decisive combat action. In their place Exasas-tactical streamed empathy algorithms and spread killware into the noosphere to connect with the remaining battle-priests and alphas.

Exasas-tactical fractured, becoming dozens of individual fighters and unit leaders while defensive protocol measures moved the warskin towards the foe, ranged weapons spewing a torrent of devastating fire.

On the uppermost level Exasas-tactical rode in the senses of an alpha leading a counter-attack against Heretic Astartes, a phaserod gleaming in his hand. He ducked beneath a snarling chainsword and thrust the phaserod into his foe’s huge plastron, the weapon’s serrated tip shifting through the armour as if it didn’t exist. A pulse of power ripped apart the Space Marine’s chest cavity, pulverising the organs within.

At the same time the magos felt the impact of a bolt round in the chest of a fulgurite battle-priestess as she hurled herself into more of the traitors on the second level, just a few metres above the dominus’ physical incarnation. Though she felt the puncture and sudden eruption in excruciating pain, to the magos the fatal wound registered as a series of negatively scaling victory factors – the closest to sadness the battle-programmed persona was likely to experience.

Bolts rang against vis armoured form, but their impacts were no distraction as ve aimed at a squad of heretics that had formed a staging point on the starboard stairwell just below the second level. From this vantage they unleashed punishing fire across the other three sides of the atrium, forcing back skitarii squads and driving the auxilia into the scurry-ways and ducts.

Taking direct control of an alpha in a skitarii squad almost directly above the knot of enemy warriors, Exasas-tactical had the squad deploy their fragmentation grenades, while simultaneously commanding another alpha on a gallery opposite to use the distraction to regroup their heaviest weapons to a better firing position. As one cogitation-thread managed this manoeuvre, Exasas-tactical’s other semi-autonomous routines likewise created crossfires against an advance on the aft third level, precipitated a counter-attack into a bloody melee from the bottom stairs of the port walls and orchestrated a feint-and-encircle with a platoon of skitarii on the third floor.

Though Exasas-tactical could not literally be everywhere, at any point when ve deployed vis focus upon a squad or battle-priest ve was able to coordinate with far greater speed and precision than any of vis subordinates. Ve pinpointed weak points in the armour of a squad that continued to unleash devastating salvos of sonic blasts from the uppermost galleries. With this information several disparate squads combined their fire with drastically improved effect, felling three of the augmented warriors in their following fusillade.

Even lone marksmen stalking the vaults felt the momentary presence of the magos, steadying their biological systems, prioritising targets and implementing redeployment commands.

The connection was not one way. Exasas-tactical received continual input from the slaved skitarii, so that ve could monitor casualties, fear responses and fatigue, and inload specific local data that remained out of detection of vis suite of personal scanning systems. While auditory receivers registered the crack of bolts and shouts of the angry and dying, a far more elaborate battlescape played out in vis cogitational circuits. Degrading combat capabilities of both sides registered in various hues of blue and red, conveying an almost physical need to bolster in certain places, demonstrating the ability to relent in others.

The entire force was an extension of the warskin, Exasas-tactical wielding the squads under vis influence as a warrior might use their own body. Each squad was a separate limb, each soldier a digit upon it that could be turned to a particular task if need be, whether an opportune counter-strike in close combat or a timely arc rifle shot moments before the target moved out of the shooter’s sight.

Like the eye of a vortex, all of the activity whirled down into Exasas-tactical, and through ver the battle for the atrium raged. The strategic necessity for the defence had been affirmed and now all that remained was the execution of the conflict. The enemy had made no move that betrayed any objective other than the atrium floor and access to the command and mechanical decks, and although this single-mindedness made it relatively straightforward to predict their behaviour, physically stopping such a determined assault was far more problematic.

Chapter 7

The Cybernetika

Strobing las-fire and the echoing snarl of bolter rounds warned that the fighting was not far ahead. Flashes lit the frieze-painted walls with splashes of blue and red. Sparks of bolts descended past a high archway at the end of the passage, met by the rising beams of lasguns and the tamed lightning of arc rifles.

‘Quick,’ said Aszad, hurrying forward. He ran awkwardly, his crushed arm tied across his chest with his belt as an improvised sling. In his free hand he carried his stub pistol, waving them on.

Arc rifle in hand, Harkas ran alongside Dazi, leaving Ghelsa to follow. Several dead skitarii were piled in the archway, ripped to pieces by bolt rounds as they had entered the corridor. Harkas hung back with Ghelsa as the two vent-fighters edged forward.

With an encouraging nod, Dazi beckoned them on, waving for them to crouch behind the bodies as she peered out into the chamber beyond. Ghelsa leaned forward to see where they were, resting her weight on the bloody remains of a skitarii soldier.

The ‘stairs’ Aszad had mentioned turned out to be the transit atrium between the upper levels of the akropoliz and the chambers around the antae that led to the holy decks. Delving five storeys into the Casus Belli, the atrium was lined with vaulted galleries, four open stairways ringing the walls from top to bottom.

They had arrived at a landing halfway down, literally in the middle of a firefight. Traitor legionaries held the upper floors, standing at the rails and firing down at the defenders taking shelter in the adjacent corridors and halls. White-clad bodies littered the stairs and landings, the pale stone splashed with crimson. Bullets whined into the renegades from above as duct-runners sprang monkey-like between the girders of the vaults and others fired from the atmospheric circulation hatches. Now and then a traitor turned his weapon upwards to unleash a storm of bolts, but the nimble Armageddon veterans never remained in one place long enough to suffer the return fire.

‘We can’t go out into that,’ said Ghelsa, reeling back as a bolt exploded on the walkway just in front of them. Shards of ferrocrete spattered the corpse mound and fell onto her.

‘Not yet, not yet,’ agreed Dazi. She shuffled to the archway, leaned out to snap off a brace of shots and then scuttled back to them as bolt detonations threw shrapnel from the arch and floor. ‘Friends will be coming soon. Friends with bigger guns.’

‘How soon?’ demanded Harkas.

‘As soon as they are woken up,’ said Aszad. ‘No sooner.’

‘There must be some other way down,’ said the inquisitor.

‘Plenty,’ replied Aszad. ‘But they are sealed to stop the enemy using them. The big gates are shut, and that channels them here to be killed. Unless you have an override?’

‘We can take you another way, through the vents,’ said Dazi. She looked at Ghelsa and shook her head sadly. ‘But not you, big one.’

Ghelsa met Harkas’ gaze and nodded.

‘You should go,’ she said. ‘You don’t need me anymore.’

He looked disappointed but answered with a nod of his own.

‘You have delivered me to the akropoliz, as we agreed. The hyperezia will not be looking for you here.’ He paused as the crack of a fragmentation grenade reverberated up the atrium, followed by an intense thunder of bolter fire. ‘Thank you for your assistance so far.’

Ghelsa was lost for words, not quite sure how she felt. Harkas was right – she had achieved what she had set out to do. And yet it felt like she had an unfinished task to complete.

‘Who are you, strange one?’ Dazi asked Harkas. ‘What do you want in the command decks?’

Harkas shook his head. ‘I cannot tell you.’

Ghelsa was about to speak up for him, to tell the others that Harkas was an inquisitor, but she stopped herself. It was clear he did not want to share that information. More than that, for the first time since they had fled the hyperezia, she asked herself whether she really knew what he intended.

‘I can see you are tributai,’ Aszad said to Ghelsa. He jerked his head towards Harkas in his stolen uniform. ‘He’s no skitarii. Do you trust him?’

A terrible thought cast its shadow on her. What if Harkas was with the rebels? His insistence on coming to the akropoliz seemed convenient now. Had he known about the traitor legionaries’ plan to launch an aerial attack? As much as his outlandish gear and attitude might make him an inquisitor, it was equally likely he was trying to get to the holy decks to open the doors and let the renegades in. Had she been complicit in letting a heretek gain access to the holiest part of the Casus Belli?

Her stomach knotted in apprehension and she forced out a few words. ‘I’ll come with you.’

‘It’s too small,’ said Dazi.

Harkas walked a little way back down the corridor, gesturing for Ghelsa to accompany him. She bent down to hear his whisper.

‘I have to get to the moderatus prime to retrieve my sigil. If I can get into the command centre with Dazi, I need to do it.’

‘I have a better idea,’ said Ghelsa, thinking as quickly as she could. She had only a half-formed idea but knew Harkas wouldn’t give her the time to mull it over. She just had a bad feeling – that clumsy, organic instinct again – and didn’t want to let Harkas get away from her. ‘There’s no point getting in there if the traitors break in and kill everybody straight after. They could even be working with the hereteks. If they reach the antae then what’s to stop the tech-priests just opening the gate for them? Why not drive out the traitors first and then get our new friends to take us in after that?’

He sat back on his heels, considering this, the arc rifle across his knees. From the atrium the sound of bolters and the crash of armoured boots grew louder, signalling a renewed assault by the traitors. The skitarii fusillades intensified in response, lighting the corridor with azure and scarlet reflections.

‘You are right,’ said Harkas.

He stood up and checked the power cell on the arc rifle with a surprisingly practised motion, obviously familiar with the weapon. There were so many little contradictions, it drove Ghelsa mad trying to pin down who he really might be.

Harkas pointed the gun at the bodies strewn across the corridor and then to her multi-tool.

‘You might want to get yourself a weapon with more range,’ he said.

‘I don’t think so.’ Ghelsa eyed the arc pistols and mitralocks. ‘I’m tributai, not skitarii. I’m just as likely to blow your head off as do any good with one of those.’

Harkas looked at her, frowning. ‘Being tributai does not define you, Ghelsa vin Jaint,’ he said, stepping close. ‘Do not let others restrict what you can be.’

‘I am not ashamed to be tributai,’ she replied, angry at the assumption and condescension in his statement. ‘Without us the Casus Belli would be an empty shell, like a corpse drained of blood. The Machine-God gives it spirit, but all of us together – duluz, hyperezia and skitarii – bring it to life.’

‘Have you never wanted something more? What if you could ascend to the ranks of the tech-priests and travel closer to the Machine-God?’

‘That’s what you don’t understand.’ She touched the cog symbol in her forehead and then ran her fingers along the struts of her exo-skeletal arm. ‘I already travel in the sphere of the Machine-God. They gifted me these as reward for my dedication. You think the Cult Mechanicus despises the flesh, but the biologis teach us that even flesh is a machine, simply forged from different materials. The Machine-God is in our thought processes, not our limbs and organs. You disrespect that when you give me stimms without my consent, without offering supplication to the spirit they have placed within me.’

She stopped, shocked by her own vehemence. Harkas looked at her oddly. He seemed offended at first and then cautious.

‘I did not mean to cast aspersions on your faith, tributai, but to compliment you on your resilience and resourcefulness.’

Ghelsa noted the lack of an actual apology in the explanation and was about to iterate that point when the cough of stub pistols and a shout from Dazi drew their attention back to the atrium.

‘Some help here, strange one,’ Aszad called.

Armoured warriors were descending the steps on the opposite side of the hall, bolts and plasma blasts preceding them like a bow wave, carving apart any skitarii caught in the fusillade. Converging arc-flashes and lasbeams scoured across their armour, but they advanced into the storm heedless of any danger.

The Armageddon fighters and Harkas added their fire to the defence, bullets and arc-flares blazing across the divide. One of the lead giants stopped his advance and turned towards them, bolter raised. Dazi threw herself across Harkas, knocking them both flat, while Aszad dived against the corpse pile.

Ghelsa stood transfixed as bolt rounds exploded across the bodies, detonating viscera into the corridor. A second salvo ripped a fresh swathe through the corpses, shattering dead bone, tearing cold flesh.

Harkas and the two tunnel fighters were pinned down behind a depleting wall of the dead. In a few more seconds the corpses would be ripped apart, denying them the last shreds of cover.

The gleam of a plasma coil drew Ghelsa’s eye to one of the bodies closer to her. There was a plasma caliver in the soldier’s dead grip. The pulse of the energy cell called to her like the insistent blink of a warning indicator. From her position, the Space Marine was just in sight, but the corpse was in full view of the traitor. If she moved she would step directly into the line of fire.

Another staccato of wet explosions and a dismayed shout from Dazi spurred her into action.

She bounded forward, covering the width of the corridor with a single calliper-assisted leap. She stooped and tore the rifle from the skitarii’s grasp and then turned, raising the weapon in one hand. A shrunken, ruddy image of the Space Marine moved back and forth in the sight along its length, appearing and disappearing as her hand wavered.

Still boosted by the vestigial effects of the combat stimm, Ghelsa tracked the course of the next bolt to erupt from the Space Marine’s weapon. It slammed into the wall between her and the others, a midpoint in a continuing burst that was moving towards her.

She pulled the trigger. A fist-sized sphere of blue plasma sped across the atrium and smashed into the traitor’s chest even as the next round left the muzzle of his boltgun. The armoured warrior fell back into the wall, scattering shards of molten plastron, but Ghelsa’s attention was fixed on the spark of bolt propellant as the projectile raced towards her.

It scorched past her face, the spit of propellant burning her eyes, hot air washing over her skin in the heartbeat before it slammed into the wall further down the corridor. A split second later it detonated, spraying shards of plascrete into her arm and leaving an uneven pattern of white dots across her skin. Her ear buzzed painfully, partly muting the ongoing sounds of battle.

Dazi, Aszad and Harkas rose up from their hiding place and dashed towards her. A fresh welter of bolter impacts tore into the archway where they had been, chasing them down the passageway.

The two xenagia tackled her together, driving her away from the line of fire just an instant before the white-hot beam of a lascannon slashed into the corridor. They hit the floor hard, Harkas jumping over the tangle of their limbs to evade the incoming fire.

Rolling over, Ghelsa half jumped and half crawled after the inquisitor, her breath coming in short gasps. Dazi and Aszad caught up with her, hooking their arms under hers to haul her fully to her feet.

Together, the four of them fled for the shelter of a doorway a few metres further down the passage. Ghelsa sank to her knees in the small chamber beyond, her shoulders heaving, her leg bracing scraping the tiled floor. Harkas stopped inside the arched doorway and peered out. He jerked back suddenly and a bolt trail sped past the opening a second later.

Ghelsa followed his gaze as he looked around the chamber. It was a storage space, lined with shelves on which were stacked neat piles of chamfered discs and assorted sealed cardboard boxes. Aszad and Dazi performed their own quick inspection, pulling aside crates to see if there were any vents below the lowest shelf. There was nothing, only solid wall.

‘At least we’re safe in here, even if we can’t go anywhere,’ said Ghelsa, hauling herself to her feet with the help of Harkas’ outstretched arm.

‘If the traitors don’t reach this level of the atrium,’ said Aszad.

‘Or break through at the outer gate and arrive from the same way we came,’ added Dazi.

Without spoken agreement, Harkas and Ghelsa backed away from the door until they reached the wall. The two Armageddon veterans stacked more boxes to create a barricade across the entrance, and then another line of crates further back that they could shelter behind.

‘Don’t worry, help is on its way,’ said Dazi. ‘Our tunnel-kin will find us, or we can wait for the skitarii to secure the area again.’

‘You mentioned something else, other forces being readied,’ said Harkas. ‘How much longer until they arrive?’

‘Not long, I’m sure,’ said Dazi. ‘And then the serious fighting can begin.’

They waited. The sounds of battle waxed and waned along the corridor, sometimes so intense it was hard to imagine anyone from either side might survive, and at times almost falling silent as the combatants simultaneously regrouped. Each resurgence of gunfire was accompanied by indecipherable shouts, the metallic echo of binaric and the distorted amplified war shouts of the traitors. Now and then one of the tunnel rats would identify specific weapons, plucking a particular zip or bang or hiss from the cacophony. Judging by the smiles and little laughs they shared, it seemed to be some kind of game.

Ghelsa had the plasma carbine resting on a crate, aimed directly towards the centre of the door. The others had their weapons couched more comfortably, lacking a lockable exo-skeleton to take the strain of aiming for so long.

‘You would make a very good fighter, you know?’ said Aszad. ‘Not so good for vent-crawling, but very strong, very big.’

‘I don’t think I’m suited to it,’ said Ghelsa, remembering her episode of dizziness. ‘I prefer taking on coolant leaks to enemy fighters.’

Nothing more was said, and Ghelsa’s thoughts began to turn, chasing themselves around her head. Without the distraction of conversation she feared she would screw herself too tightly and lose control again.

‘How long have you been on the Casus Belli?’ she asked, trying to sound calm.

‘Nearly four years, I think,’ said Dazi. ‘We grew up on stories of how our ancestors fought in Hades hive against the orks. When the tech-priests came to Acheron, we fought our way up into the hive city to offer our blades to the Legion in return for their sacrifices for our world. A great day for us that they accepted.’

‘Your Princeps Mannheim, he is a saint on Armageddon, did you know that?’ said Aszad. ‘He has a holy day almost as grand as Yarrick’s.’

‘I did not know that,’ said Ghelsa. She saw confused inquiry written in Harkas’ face. ‘How can you not have heard of Kurt Mannheim, hero of the Legio Metalica?’

‘The Imperium is vast, and you cannot expect someone to take an interest in every war that has occurred and every hero that has arisen in ten thousand years. I know little of the troubles of Armageddon.’

‘It was during the First War, when Beast Ghazghkul invaded,’ she said.

‘I think you mean the Second Armageddon War,’ he replied.

‘She is right – it was the First War, when the greenskins brought destruction to our world.’

‘Of course,’ Harkas said hurriedly. ‘Yes, it was the First War. There have only been two, yes?’

Ghelsa frowned at his ignorance and shook her head derisively.

‘The traitor, Overlord von Strab, ordered the Titans of the Legion into battle against impossible odds.’ When she said the turncoat governor’s name, Dazi and Aszad made slashing motions across their throats and then spat on the floor, hatred burning in their eyes.

‘His soul burns in the abyss,’ snapped Dazi. ‘Long may he suffer.’

‘Mannheim obeyed though he knew he could not win. Despite the odds, the Legio ended the profanity of many ork war engines in that battle, and even when his noble Warlord Steel Hammer was close to destruction he pressed into the foe and overloaded the reactor to destroy as many greenskins as possible.’

‘Praise Mannheim, his sacrifice endures as we endure,’ intoned Aszad. ‘We can hope that our souls will be elevated to the Emperor upon the fires of battle too.’

‘Why did he obey?’ Harkas asked with a frown.

A flurry of bolter fire that sounded quite close had them all pointing their weapons at the door again. After several seconds the sound relented.

‘Perhaps we should take another look,’ suggested Dazi, looking at her life partner. ‘It would be bad to sit here waiting when we do not have to.’

Aszad vaulted over the crates and then dropped to his belly to slide serpent-like to the doorway. He pulled a thin rectangle of polished metal from the waistband of his trousers and held its end between a slender thumb and forefinger. He eased the mirror into the corridor, angling it for a moment to look towards the atrium.

He rolled sideways and threw himself from the door moments before a bolt impacted on the frame, hurling fragments of plascrete and paint across the retreating duct-runner.

‘Still not good,’ he said, taking position once more.

Though dozens of soldiers gave their lives for the Machine-God, the Space Marines drove them to the lowest two levels. Occasional databursts from the logistari Monderas informed Exasas-tactical that the external threat to the akropoliz had been neutralised and no further enemy were incoming. The forces defending the main gate and upper gun batteries were thus devoid of duty and Exasas-tactical retasked them to the atrium.

Exasas-tactical lacked the ability to predict fully whether such reinforcements would be able to intervene in time. Their imminent arrival might well spur the enemy into a final attack, knowing that they fought on only for death or victory. Alternatively, if they detected fresh forces on their way the Heretic Astartes might well secure their positions and attempt to fight a more protracted engagement.

Neither was a promising prospect, with the Casus Belli actively fighting to breach the citadel. While ve cut down the first of the Space Marines to reach the atrium floor with a swipe of a gleaming blade, a flash of strategos-think entered Exasas-tactical’s mind.

The leg bastions were empty.

It was entirely possible that the Heretic Astartes had attacked purely to divert all possible defenders to the akropoliz.

Exasas-tactical had not the ability nor the inclination to investigate this further and filed the idea away into a sub-packet for Exasas-non-tactical to deal with as ve saw fit.

The distraction was unfortunate, drawing away Exasas-tactical’s attention for almost a whole second. Too late ve detected a trio of Space Marines leaping from the uppermost level, their jump packs flaring as they plunged directly towards the heart of the fighting.

The magos’ thought-imperatives scorched through the minds of vis soldiers, directing all excess firepower at the descending giants. Arc rifle fire scoured the divide in a roiling tempest while phosphor rounds cracked white fire across the armoured warriors. One of the Space Marines fell like a comet, crashing into a first-level gallery, the impact slaying half of the skitarii squad deployed at its rail. The other two controlled their descent with more bursts of jump pack glare.

A sudden change in course took one of the Heretic Astartes into the remaining corpuscarii and fulgurites who had gathered around the dominus as a final line of defence. The second landed directly atop Exasas-tactical, the weight of impact slamming the magos to the floor.

Emergency self-preservation routines burst into life, performing a rapid triage of the immediate danger. Exasas-tactical whipped a gleaming combat blade towards the Space Marine atop vis shell, catching the chainsword aimed at vis phosphor blaster. Serrated mandibles sprang from vis carapace and locked around the bolt pistol in the warrior’s other hand, crushing it.

The other Space Marine hacked his way through two fulgurites, his chainsword trailing electricity-laced blood from the wounds. Ducking beneath the staff of another, he hacked the legs off a third and rolled underneath Exasas-tactical.

It was immediately obvious that the magos was being targeted directly, a normative-protocol decapitation attempt. Exasas-tactical resisted the desire to dump-load vis cerebral context into the noospheric archive for later restoration. The action itself would likely precipitate vis physical demise and the subsequent loss of the atrium. Instead ve turned those precious moments of processing into a burst of action.

Taking up a tripedal stance, the magos snapped a bladed foot up under verself, puncturing the back of the Space Marine driving the tip of a chainsword at Exasas-tactical’s armoured underside. At the same time, ve detonated the ammunition of vis serpenta, sending waves of system static coursing through vis hardware. Despite the intense discomfort, this had the desired effect of blasting the other Space Marine from the magos’ back, sending the Heretic Astartes crashing to the floor, molten flesh and armour indiscernible from each other.

With all of vis attention fixed upon immediate survival, the magos had no spare output to bolster the defence. A dozen Heretic Astartes had reach the first level, uncaring of the skitarii above them, determined to force their way to the antae of the command module and the gates of the torso decks.

The warrior beneath the magos continued to blast with his bolt pistol, chainsword wedged into a crack of Exasas-tactical’s abdominal armour. With one leg now pinned into the superhuman soldier, the magos lacked any means to attack – if ve simply let vis weight drop onto the Space Marine it would only drive vis body onto the whirring teeth of the chainsword.

A fatality-imminent protocol boiled through vis processors and activated the warskin disengagement routine. It was intended as a final attempt at escape but had the effect of dropping Exasas’ inner body directly on top of the Space Marine.

Shocked, just as vis attacker likely was, Exasas flailed mechadendrites, interface spikes and grappling appendages at the heretic’s ornate helm. A diamond-tipped interface plug pierced a lens and punched into the eye and brain within. The retort of the Space Marine’s bolt pistol almost overloaded Exasas’ auditory pickups and ve felt a very real explosion of pain in vis upper torso.

Ve continued to stab wildly at the heretic’s facial area, scrabbling at the armoured form with a flurry of propulsive limbs.

Sensory input finally registered the Space Marine as deceased a few seconds later, though Exasas remained unsure which actual blow had caused this positive outcome. Further investigation into the immediate situation was curtailed by the flood of strategic data flooding into ver through the noosphere.

Vis consciousness expanding out through the layers of the akropoliz and beyond to the battle that raged outside the Titan, Exasas was swept away as though confronted by the touch of the Omnissiah himself.

The battle-din did not lessen, and in fact increased over the next few minutes. Not only did the noise intensify, it moved closer – even Ghelsa could tell. She swallowed hard and wiped the sweat from her hands on her coveralls. Amid the noise she had become accustomed to was a semi-regular pounding, like heavy footsteps on stone. It grew louder and louder, a continuing crash accompanied by furious gunfire. Beside her Dazi and Aszad shifted nervously, their own unease adding to her discomfort. The two tunnel fighters shared a glance.

The thudding was definitely heading along the passage towards them. Sporadic bursts of light from the atrium cast a broad shadow along the floor, from something far larger than a normal man. Ghelsa’s finger trembled on the trigger and she almost opened fire by mistake.

Teeth gritted, she waited, the footsteps now just outside the door.

Something armoured in white-and-red plate stepped into view. Dazi jabbed out an elbow just before Ghelsa opened fire, knocking off her aim so that the plasma bolt struck the shelves instead of the mechanical beast before them.

In the next moment Ghelsa saw the construct properly. It was certainly bigger even than a Space Marine, its domed head almost touching the high ceiling. The frieze of the corridor was reflected in a mirrored visor-face that turned towards her, independent of any movement from the rounded shoulders that flanked a barrel chest. A flame-throwing weapon pivoted over the shoulder from a spinal mount, the flicker of its ignition spark leaving spots dancing in Ghelsa’s vision. Heavy forearms contained the muzzles and magazines of solid shot weapons where hands should have been. These too lifted towards her as the automaton squared its bulk towards the open doorway.

A kastelan.

<Identify.> The construct’s voice was deep and slow, each syllable precisely enunciated but distorted by the synthesiser that created it. Its arm-mounts tracked them with stiff movements and the whine of servos.

‘Faithful!’ said Dazi, standing up, her pistol held out to one side. ‘Scan your datastore.’

It regarded her in silence for several seconds and then dropped its arms to its sides.

<Major Dazi Asheal identified.>

‘Major?’ Harkas and Ghelsa uttered the question at the same time, equally incredulous.

Dazi frowned at them. ‘What confuses you?’

‘I didn’t realise you had ranks,’ confessed Ghelsa. She ineffectually waved a hand at Dazi’s sparse clothing. ‘I would have expected… a uniform?’

Dazi sighed and turned her attention back to the kastelan.

‘Identify yourself and your unit.’

<Delta 6-Terror, Emancipation maniple.>

‘Where is your datasmith?’

<Inoperational. Independent action initiated.>

‘And what is your standing control order?’

Two more kastelans strode past the construct, heading towards the gatehouse hall.

<Destroy the enemy. Secure the battlezone. Protect the faithful.>

Ghelsa felt the kastelan turn its scrutiny on her and Harkas, though it had no face as such. She flinched when a red light gleamed behind its visor and its weapons rose towards her.

<Unidentified combatants.>

Dazi stood in front of the cybernetic warrior and looked at Ghelsa and Harkas as though she hadn’t seen them before, her eyes narrowed.

‘That’s true,’ she said. ‘You never did say what you were doing up here, tributai, or who that is with you. Why are you so desperate to get into the command deck?’

Ghelsa looked at Harkas for help, but the inquisitor remained silent. She glared at him, trying to urge him to speak.

‘Put down your weapons,’ said the major, her tone terse. Ghelsa let the plasma carbine drop onto the crate and stepped back. Harkas gave up possession of his arc rifle more reluctantly. He hadn’t moved his stare from Dazi during the entire exchange.

‘They were fighting the traitors,’ said Aszad.

‘I’m aware of that, which is why they’re still alive,’ said Dazi. She smiled at Ghelsa, but there was little warmth in it. ‘Thank you for saving our lives.’

‘I think I owe you that thanks more,’ Ghelsa replied. ‘That traitor legionary would have smeared me across the wall if you hadn’t arrived.’

‘We wouldn’t have caught him if you hadn’t slowed him down,’ said Aszad with a lopsided grin and a shrug. His levity was ended by the sound of an explosion.

‘I need to get to a vox station and find out what’s happening, and I don’t have time for… whatever this is,’ said Dazi.

‘I’ll watch them,’ offered Aszad.

‘No, you need to get back to the platoon and coordinate the attempts to reclaim the upper storeys.’ She turned to the kastelan. ‘Delta 6-Terror, can you comply with fresh orders?’

<Your authority is recognised, major.>

She eyed Ghelsa and Harkas, seemingly weighing up her options.

‘A compromise,’ she declared. ‘Delta 6-Terror, you will escort these two unidentified combatants to the command deck, and when there, deliver them safely into the custody of the hyperezia.’

<Understood, major. Categorise unidentified combatants for engagement parameters. Are they faithful or unfaithful?>

The major considered the question, looking first at Harkas and then Ghelsa. The tributai wasn’t sure exactly what difference the definition made to the construct’s soul-program, but she was certain she didn’t want to be categorised as unfaithful.

‘You I trust,’ declared Dazi, looking at Ghelsa. She switched her gaze to Harkas. ‘I’m not so sure about him.’

‘I vouch for him,’ Ghelsa said quickly, before she had even thought about the consequences. She tried not to let an instant of regret show.

‘You do? Then if I trust you, I must accept your word for him. Delta 6-Terror, categorise combatants as faithful.’

<Praise the Omnissiah, hail the Machine-God.>

‘Hail the Machine-God,’ echoed Ghelsa, letting out a ragged breath.

The sensation of lightness quickly became a more solid realisation as Exasas’ thoughtfilters switched from tactical to strategic mode. The uplifting effect of the noosphere was caused by the untrammelled presence of the Casus Belli’s spirit, focused through the MIU of the princeps senioris. It radiated a stillness of soul. Not calm, as the spirit of a Titan was ever belligerent by intent, but the violence at its core had become a latency from the actuality. One might think it was relaxing.

With noospheric links established with the command module, Exasas discovered that the source of this dormancy was a cessation of external hostile activity. The battle group had finally silenced the guns of Az Khalak and were circumnavigating the broken citadel, intent upon the valleys beyond as directed by the princeps senioris’ order.

A dichotomy sparked within the magos dominus as ve regarded the completion of the primary mission on the one side against the counter-attack of the cybernetika that was still ongoing. It was not the first time that the travails of the skitarii were beneath the notice of the Imperator, which probably regarded its human – and once-human – protectors as little as a duluz heeds the presence of its own antibodies.

A perfunctory assessment reassured the dominus that while several Space Marines had escaped to wreak sporadic damage through the akropoliz, there was an absolute-zero probability of a further threat to the command module or lower decks.

Any positive effect on Exasas’ mood at the thought of the dual victory quickly abated when the magos appraised verself of the casualty records. A large proportion of the skitarii were dead, their absence like a blockage in the datastream that nagged at the magos. The auxilia, as much as ve could tell at this stage before accurate reports had been submitted, had suffered equally harsh losses.

Even more distressing was the preliminary finding of the kill-efficiency equations, putting the performance of the defenders at a little over 60 per cent. Not only had the victory been costly in terms of personnel, but the expenditure of ammunition and energy cells had almost depleted the skitarii armouries.

Exasas resolved to recalibrate the oppositional factors for the Heretic Astartes in light of the data gleaned from the battle. All previous differentials had been based upon non-personal experience or archival records, and thus divorced from proper investigation. The reality of facing the Traitor Space Marines was far more informative than the rumour; even though Exasas had downgraded many reports as being exaggerations, the truth was that perhaps much of the archive data ve had threaded into the calculations had underestimated the lethality of the fallen creations of the Omnissiah.

Pre-calculated effectiveness estimates rated the overall standing of the dominus’ defence forces at 12 per cent. Estimating survival rates among the wounded while reviewing their individual battle-memories to experience the extent of their injuries, Exasas engaged defensive failsafes that dedicated the remaining troops to key positions in the akropoliz and bastions. The cybernetika remained the most battle-ready asset, but their inflexibility made them poor substitutes in many situations. Exasas left them with their current task of exterminating the renegades still at large.

Evidence of Exasas’ adjustments was immediately visible when a skitarii alpha led her team to the antae gate leading from the atrium to the command module. Elsewhere troopers redistributed their weapons and ammunition, quickly creating more effective fire teams while those that gave up their armaments moved among the dead and wounded, acquiring what other materiel they could.

In some form or other, they would be ready for the next threat to the Imperator.

Chapter 8

Time of Judgement

The sounds of fighting had moved away by the time the tunnel fighters led them back towards the atrium. With Delta 6-Terror looming behind them, they followed the two Armageddon natives out into the great hallway. The dead of both sides choked the stairs and galleries, the smoking carcass of a construct here and there among the organic ruin. The air was thick with smoke and the stench of blood. Erratic bursts of fire lit the stairways as squads of skitarii moved among the corpses, firing point-blank into the traitors to ensure they were truly dead, hacking off their heads with buzzing transonic blades.

The walls were blackened by las-fire, cratered with plasma impacts and bolt wounds, scarred by deeper welts and molten abrasions. Ghelsa laid a hand on the cold ferrocrete wall, hoping that the comforting gesture, small as it was, soothed the spirit of the Casus Belli in some way.

Brave warrior, she thought. If I had but a fraction of your strength, indestructible master of war.

‘Go with Delta 6-Terror and report to the hyperezia,’ Dazi told them. She laid a hand on Ghelsa’s arm and leaned close, her voice a whisper. ‘Whatever loyalty you think you owe this man, remember that your oaths to the Legio surpass it.’

The urge to confess everything welled up within Ghelsa. She clamped her jaw shut, worried that some stray word might condemn her to further examination. She answered with a brief nod, afraid to speak.

<Descend,> instructed Delta 6-Terror, using its bulk to shepherd them towards the closest steps.

Harkas set off, shoulders hunched, fists clenched. Ghelsa picked her way over the shattered armour of a traitor legionary, trying not to look at the unpleasant designs moulded into the ceramite – images of degradation and violence that made her shudder even only half seen. Delta 6-Terror made no effort to avoid the renegade, crushing battle plate beneath it as it stomped down the stairs behind her.

They had descended two flights when Harkas paused for a few seconds, allowing her to come alongside him. Not so suited to the steps, Delta 6-Terror was a few metres behind.

‘I think we can outpace the construct,’ he said quietly, keeping his gaze ahead.

‘But for how long? And it only takes one shot on target to end everything.’

‘There are still weapons to scavenge – we can arm ourselves again when out of sight.’

‘Attack it?’ The thought horrified Ghelsa. ‘That’s as bad as killing the hyperezia. Delta 6-Terror is a child of the Machine-God – it is only doing its duty.’

‘You would choose the existence of a cybernetic over the survival of everyone aboard this Titan? Perhaps I was wrong about you.’

‘What do you mean? Wrong about what?’

He fell silent as they passed a squad of skitarii standing sentry at the next landing. When they reached the next set of steps he continued.

‘I thought that you possessed the moral courage to help me.’

‘I do!’ Ghelsa realised she had raised her voice more than she had intended. She continued quietly. ‘I do. I want to protect the Casus Belli, but it doesn’t mean we should throw away life needlessly.’

‘It is an artificial creation – it isn’t alive.’

‘Of course it is,’ she said. ‘It has a soul – that makes it alive.’

‘Just because it has a lump of cortex wired in there somewhere doesn’t mean…’ He stopped with a frustrated snort. ‘It does not matter. Soul or no soul, if it takes us to the hyperezia we are both as good as dead.’

‘It does matter,’ said Ghelsa, not willing to drop the subject. ‘The Cult Metalica is very clear that all forms of animus are equal in labour and regard in the universal engine.’

‘Equal in labour?’ Harkas looked at her with a raised brow. ‘The magos render themselves immortal with augmentation and elixir and you toil to an early death amid fumes and plasma exhaust.’

Ghelsa said nothing, irritated by his assertion. She wished she could read the theological tracts of the tech-priests to rebut his accusations, but aside from a few common maintenance runes she was illiterate. His words left her feeling mocked and frustrated again.

‘I was referring to a greater purpose, Ghelsa vin Jaint,’ the inquisitor continued. They turned onto the penultimate landing, the steps thick with bodies in bloodied white robes and tattered coats, where the skitarii had held against the traitors’ relentless attack while awaiting the reinforcements of the cybernetika. ‘One beyond the Imperator.’

‘Beyond?’ The thought excited and terrified her. ‘In what way? I don’t want to be reallocated to a starship or forge world. The Casus Belli is my home. I belong here.’

The thought almost brought her to tears.

‘I see. I had hoped that, once my mission here was successfully concluded, you might continue to accompany me on further works in the name of the Emperor.’

‘Join the…’ She again realised she had lost control of her volume. ‘Join the Inquisition?’

‘Not as such. You would aid me in certain situations, nothing more. I admire your resourcefulness.’

As before, the words of appreciation made Ghelsa’s heart quicken. She turned her head and faked a cough to hide the smile that she could not contain.

So stark was her feeling that it almost instantly sparked paranoia. The kind words were at odds with Harkas’ generally dismissive attitude. Several times now he had belittled her faith, not to mention the insult of desecrating her Machine-God-augmented body with the stolen stimm. He spoke of respect but rarely showed it.

The thought led her to a moment of revelation.

‘I think there’s another way,’ she said. ‘I don’t know how these kastelans work exactly, but I’ve been around the tech-priests enough to pick up a few ideas.’

‘Another way to what?’

‘To get inside the holy decks without the hyperezia killing us.’

Summoning a quintet of armoury-slaved servitors to attend to the heavily damaged warskin, Exasas approached the antae and extended a noospheric cipher into the watchdog systems. Another tech-priest responded to the magos’ intervention.

Monderas: <Salutations, dominus. It is with satisfaction that I discover your continued survival.>

The immense gates opened as Exasas approached, letting forth billows of red vapour like the breath of a mythical beast. Ve advanced into the welcoming haze, puffing out clouds of vis own incense to mingle with that of the command deck, as if they were pack creatures exchanging scent marks.

Exasas: <Likewise I am grateful of the efforts of the command crew for attaining victory over the enemy citadel. Our mutual efforts serve the Machine-God’s design. I shall review the archive of the action with interest.>

Ve passed under the gateway and into the antae. The chamber was quite plain, silvered like the forge world that had raised the Casus Belli to the service of the Machine-God. A servo-skull detached from a docking alcove at the crux of wall and ceiling and floated down to the magos, the hollows of its eyes lit with a red gleam from the rudimentary cogitator within. Exasas recognised it as one of Monderas’ peripherals, one of the logistarius’ favoured students before an implantation mishap had ended her promising ascent towards the Higher Wisdoms.

It extended a data-spike, indicating a desire for physical interface. It was an unusual request, but Exasas held up a tendril that ended in a dataport and allowed the servo-skull to connect its protrusion.

#startaccess/Exasas=Monderas/shielded#

Exasas cautiously accepted the logistarius’ invitation.

#is there some issue with the noosphere of which I am ignorant?#

#the functioning of the noosphere is unimpaired to my knowledge#pertaining to the princeps senioris’ recent command we are progressing directly into the region beyond the fortress without resupply#

#this is known to me#I do not understand the need to keep this exchange from the noosphere#

#we have meteorological reports that show intense electromagnetic activity will engulf the area imminently#this storm will seriously impair the systems of the Casus Belli#we will be unable to communicate with the rest of the battle group at a time when we are not fully recovered from the losses and damage just suffered#I thought it pertinent to your conjecture that the enemy were attempting to isolate us#

#and the direct transmission is because you do not wish this exchange to be perceived as a challenge to the princeps senioris’ orders#

#correct#

#to the extent that you do not wish the rest of the command crew to even know we have conducted ciphered communication#

#the existence of such communication could be interpreted as dissent#or worse#

#endaccess/Exasas=/=Monderas/shielded#

There was a moment of dislocation as the logistarius severed the link. The servo-skull retracted its data-spike and drifted back to its docking point.

Exasas was unsure what to make of both Monderas’ peculiar behaviour and the princeps senioris’ insistence on continuing the advance when the battle group’s effectiveness was compromised. In the case of Iealona’s motivations there was a significant probability that the Titan commander was under some greater indictment from the Legio hierarchy. Perhaps the enemy’s own idiosyncratic behaviour at Az Khalak had presented an unforeseen opportunity to conclude the current war-phase at a swifter rate than previously anticipated.

Ve pondered this as ve moved from the antae into the lower but broader chamber beyond, known as the pronaoz. In direct contrast to the unadorned antae, which existed as a physical incarnation of the disparity between the mundane and the divine, the pronaoz of the Casus Belli was a highly decorated structure. The walls were lined with half-pillars with capitals shaped like mechanical devices, their interlocking gears and belts forming vaults across the ceiling. The columns were lit from above by tubular lumens powered by the holy gases, bathing the columns in reds, purples and blues, in simulation of the aurora-lit skies above the Templum Metalica Majoris.

In between the columns were rendered the mask-like faces of the Casus Belli’s creators – four great magos of near-forgotten antiquity that had raised up the Imperator to crush the enemies of the Machine-God. The magos dominus’ reflection was caught in a flat expanse in the centre, placing vis image among those of the legendary founders.

The centre of the silvered floor was inscribed with a twelve-lugged cog in golden channels, the principal points decorated with runes of electrum, copper and red iron steel. Intricate circuit tracery filled the symbol, each pathway a metaphor for the holy mysteries of the Cult Metalica, every potential course a different route to enlightenment in the service of the Machine-God, be it as biologis, hermetika, arkeotektonika or one of the other dozens of disciplines a tech-priest might study.

Exasas paused to locate the conjunction between logistarius and xilliarkus that ve currently occupied, tracing the routes from the mothernodes around the hub to the Higher Wisdoms etched into the outer ring. Over and over ve moved a needle-thin digit across the rune for hierakos. It was perhaps the most important tenet of the Cult Metalica, a measure of a tech-priest’s dedication to the ideal of rank based upon progress towards the twelve Higher Wisdoms. Though of considerable rank among the skitarii, Exasas had stalled in the middle term of vis path to enlightenment, secondary even to the moderatus prime. Ve had envisaged a period in which service upon one of the great god-machines of the Legio Metalica would elevate vis progression to knowledge, but the truth was that opportunities for accomplishment had been severely curtailed. Only continued examination and refinement of vis theorem provided any measurable increase in understanding the mysteries of the cosmic engine.

Exasas lifted away the slender manipulative tendril and moved towards the gate that led directly into the czella, the prescribed term for the command module in the lexicon of the Legio Metalica. A single portal barred entry, flanked by two herakli combat servitors. Each vat-grown brute was as big as a kastelan and modified with multi-barrelled assault cannons and jagged-toothed sawhands. They stared dumbly at the magos from under their heavy hoods, their eyes almost lost in the expanses of their flat faces. Exasas extended a noospheric link to the door control systems and the panel between the herakli hissed out of sight into the bulkhead.

Ghelsa stopped and turned on the stair, waiting for Delta 6-Terror to catch up. ‘Delta 6-Terror, confirm your mission.’

<Ensure your survival and compliance until I have delivered you to the command deck. Destroy. Secure. Protect.>

‘Confirm that our status is faithful.’

<You are confirmed as faithful.>

‘And you have an ongoing duty to protect the faithful?’

<Standard battle-parameters have not been altered. Destroy. Secure. Protect.>

‘Good. Then you cannot allow any harm to befall us until we are designated as unfaithful.’

<That is correct.> Delta 6-Terror pointed down the stair with a gun barrel. <Continue towards the command deck antae.>

Ghelsa complied, ignoring the deepening frown that creased Harkas’ brow.

‘Can you self-categorise us as unfaithful?’

<Any attempt to prevent my mission accomplishment will render you unfaithful.>

‘Like trying to escape?’ Ghelsa asked, with a meaningful look at Harkas.

<Yes. Attempted evasion of custody would be evidence of unfaithfulness.>

‘And if anyone tried to harm the faithful, would that also be evidence of unfaithfulness?’

<Yes.>

Harkas’ sharp glance signalled his realisation.

They reached the lowest level of the atrium. At the far end was the gate into the antae between two silvered pillars. The two halves of the gilded portal made the iron skull icon of the Legio, and around them were moulded the twelve runes of the Higher Wisdoms.

The entrance was guarded by a squad of skitarii, their white coats streaked with bloodstains and oil smears, in places ragged from shrapnel and burned by plasma or promethium near misses. They wore steel-coloured armour beneath and each had at least one bionic, a leg or hand or skull, silver in colour to honour their metal-clad forge world. The alpha stepped forward to halt them and held out a mechanical hand. Her other arm was a reticulated bionic tentacle that curled around the grip of a radium carbine.

‘The antae is sealed,’ she said.

<My command requires that we contact the hyperezia.> Delta 6-Terror gestured towards the gate. <Access to the antae is required.>

Only the skitarii alpha’s chin and mouth were visible beneath her visored helm, her lips forming a thin line as she considered this. Ghelsa heard a sharp crackle and realised it was a vox-caster built into her suit.

‘We have a kastelan requiring entry, magos,’ said the alpha. ‘Escorting…?’

She looked up at the kastelan and waved a hand towards Ghelsa and Harkas. ‘Who are they?’

<They are faithful. They are in my custody. They are under my protection,> the construct replied. <I require entry.>

‘Kastelan with unidentified companions,’ the alpha said.

Ghelsa tried her best to remain calm, taking particular care to regulate her breathing. She measured each breath in and out, reminding herself that her body was just a biological mechanism. She had served the Machine-God faithfully, and even if her mortal shell were destroyed her soul would survive.

A whirr drew their attention to a circular panel on the plinth of the gate, adorned with another cog symbol of the Cult Metalica. It rotated slowly through several turns and then swung outwards, revealing a hole. For a moment a green shimmer lit the interior, and then a servo-skull emerged. It drifted forward on its anti-gravity field, its eyes glowing with jade power.

The floating skull descended, trailing slender cables and tatters of parchment inscribed with benedictions of the Machine-God. Its lifeless eyes regarded Ghelsa first, small lenses within the eye sockets clicking into place as it focused.

It drifted to Harkas, and then turned its attention to Delta 6-Terror. A brief spurt of binaric erupted from the servo-skull’s speaker and the construct replied with an equally short spasm of sound.

<Protocols initiated,> grated the skull. <Faith confirmed.>

It then rose up, reversed towards the capstone and disappeared back into its hole. The cover swung shut and locked back in place.

Ghelsa looked up at the large portal, absently tapping the multi-tool with her metal-tipped fingers, the sound swallowed by the atrium. She steadfastly refused to look at Harkas, telling herself that she did not need to see what the inquisitor was doing.

A hidden mechanism clanked within the gate and the outline of a smaller entrance appeared in the left-hand door, though it was still twice Ghelsa’s height, capable of admitting a magos or kastelan. With a wheeze of hydraulics, the door opened inwards. A billow of incense issued forth, its musky smell both familiar yet alien to the tributai. She only knew it second-hand, clinging to the robes of the tech-priests, lingering in the air after their departure. It reminded her of the Initiations, and brought back memories of her implantation ceremony when she had earned her exo-skeleton and the mark of the faithful on her forehead. She remembered the incantations, the words incomprehensible but as regular as the beating of her heart, issued with digital precision by the tech-priests officiating the induction.

Caught up in recollection, it took her a moment to realise that she wasn’t imagining the mechanical chant – it was coming from the open door. And it was not just one voice but many, each separate but part of a whole like the links of a chain or the gears and belts of a motor.

It was the will of the Machine-God given linguistic form.

‘Praise the Omnissiah,’ she declared, filled with the urge to declare her faith. ‘Hail the Machine-God!’

The skitarii alpha waved for them to proceed.

<Enter,> urged Delta 6-Terror, again using its proximity to encourage them forward.

Harkas went first, but glanced back up into the atrium, perhaps considering a last attempt to flee. He stepped over the lip of the door, plunging into the whirl of light and vapours.

Ghelsa stood trembling at the threshold. It was not apprehension that caused her to delay, but anticipation. Regardless of the circumstances, she was about to enter a sanctum of the Cult Metalica. It was hard not to think of it as a reward for her efforts over the last few hours.

<Enter,> Delta 6-Terror ordered again. <Failure to comply is unfaithful.>

Nothing was further from Ghelsa’s thoughts. As she stepped into the antae she could not stop a broad grin, feeling more intoxicated by the occasion than any amount of illicit Machine-spirits had ever made her.

The czella was noospherically shielded, so that at the instant of access the magos was confronted by a welter of fresh information exchange. Ve did not have to tap into a feed – it was simply there, filling the air like the swirls of incense. Updates and datalogs seeped into vis cogitators as ve moved through the archway and headed towards vis assigned monitoring position. Detecting the noospheric signal emanating from Exasas, the station’s spirit awoke, broadcasting a medley of welcome and security messages that the magos unconsciously swept aside into short-term archive.

Ve accessed the meteorological profile that Monderas had highlighted but there was no need to rely on the prognostications within – the tumultuous environment of the Aza Fai Alessa was plainly evident from the surveyor readings and the view through the main canopies.

Beyond Az Khalak the mountains reared into steep peaks that scraped the clouds, their flanks scoured down to dirt and rock by millennia of previous industry. The fortress guarded a pass of sorts, a vast natural gorge broad enough for the battle group to advance along at wide dispersal, stretching deep across the central highlands that dominated the main southern land mass of Nicomedua.

The clouds themselves were dark thunderheads touched with strange coruscations of red that lit them from within, a product of unnatural climate alteration. At some unknown time in Nicomedua’s history the world had been augmented with atmospheric processors, presumably to boost agricultural production. The mountains themselves had been turned into housing for these vast climate manipulators, their pinnacles pierced with hundreds of large venting shafts that had since been turned into a sprawling network of caves and corridors that had homed millions before the rebellion. During the Age of Strife the processors had fallen into inevitable disrepair and their malfunctioning had created extreme and erratic storm conditions around the mountain, not just affecting wind and precipitation but actively eroding the upper layers of atmosphere so that the highlands were infrequently bathed with heightened levels of stellar radiation.

One such burst was already affecting the weather patterns, creating a monumental tempest in the valley lands directly ahead of the battle group’s advance. Jagged spears spat groundwards in a continual discharge, lighting the darkness that swathed the pass. The tips of the mountains were wreathed with their own blue halo of glimmering plasma, as were the hundreds of gargantuan conductor rods that had been erected to harness the energy-generation potential of the constant storms.

The battle group’s remaining Warhounds advanced towards the atmospheric maelstrom, silhouetted against the flashes of power. The Imperator and Warlords followed just a few minutes behind, leaving the smaller Reavers and Warriors to form the rear of the group.

Even at range Exasas could feel the noospheric disruption of the stormhead. As tinnitus might befoul the hearing of a normal human, so the tech-priest sensed a background buzz through vis datasystems.

Iealona [general broadcast/imperative]: <Void shields will not be operational. Surveyor range reduced to minimum. Reactor relays and other systems will also be affected. All god-engines to advance at moderated pace.>

A tension sparked through the datalinks but Exasas could not separate the growing external influence on the noosphere from the negative impact of vis companions’ apprehensions. The noosphere entered a lull phase, the only contact from the unthinking servitors, all sentient minds within the command module turned inwards to their own monitoring systems. From the princeps senioris flowed a sense of purpose, the Casus Belli set upon its course with a solid determination despite the perils ahead. Positive indicators caressed Exasas’ calculations, improving the outcomes of vis extrapolations.

In the stillness of the noosphere Exasas picked up a flurry of ciphered exchanges between the moderati. Remembering Monderas’ comment about such coded conversations, the magos wondered what this peak in activity signified. A possible explanation revealed itself just a few seconds later, when the princeps senioris issued a battle group-wide pronouncement.

Iealona [general broadcast/imperative]: <All god-machines are to come to an immediate halt and assume defensive standings. Await further instruction.> [local/informative] <Contrary to previous instruction the Casus Belli will receive skitarii replacements. We shall rendezvous with rapid-deployment troop carriers before proceeding.>

Taken aback by this announcement, it took Exasas a while to process the full implications. Even as ve made subservient inquiries through the noosphere ve gave voice to the protest that boiled up.

Exasas [interrogative]: <Why was I not consulted in the particulars of this decision?>

Iealona: <You were otherwise engaged in the final conduct of purging the enemy. To avoid further delays to our advance, the motion was forwarded to high command and approved without your input.>

Exasas [protest]: <This is a further unorthodoxy to which I have been subjected.>

Iealona: <What you term unorthodox I think of as simply expedient. The running of the Casus Belli and the conduct of our campaign do not revolve around your personal needs, dominus.>

Though there was no rebuke assignation on the transmission it was hard for Exasas to interpret these words as merely literal. It was highly irregular that ve had not been informed earlier of the princeps senioris’ desire to reinforce the skitarii complement.

Gevren: <Had you not expended so many of your soldiers, we would not be forced to replace them in this manner. As well as a fresh skitarii company, the reinforcements will be commanded by their own magos dominus.>

Exasas [substantive/imperative/rebuke]: <Operational and tactical command of all skitarii forces will reside in me unless I receive direct contradiction from Legion command.>

The magos’ outburst was fuelled, in part, by indignation at the moderatus’ innuendo, that ve had been in some way inefficient in vis defence of the Imperator.

Iealona [injunctive]: <You will extend all possible cooperation to the incoming forces, dominus.>

The princeps senioris’ statement was accompanied by the full weight of Casus Belli’s personality, impressing upon the tech-priest the importance of their position. Exasas’ concerns felt petty against the Imperator’s needs, and had ve been consulted ve would have accepted reinforcement, if not outright argued in its favour. It was irrational to allow the emotive substance of being circumscribed to dictate the future safety of the Imperator.

Exasas [apology]: <I will share all datalogs and calculations with the incoming forces.> [inquiry] <Please identify the source and commander of the incoming forces.>

Monderas [datalog]: <They are akinakuz augmentatii of the Krysaorian League under the guidance of Magos Dominus Exceptis Keterina-Ga Skitara Syntamatarkias Olvatia. They are being deployed by skyspear and will arrive in eight point three minutes.>

To Exasas, who typically measured interactions in milliseconds, it seemed a very long time to wait.

The haze of incense obscured a floor polished to a mirror shine, so that Ghelsa caught occasional glimpses of her own reflection between wisps of diffused scarlet. It was cold underfoot, bare metal beneath her naked feet. The ceiling was the same, and it felt as if she had stepped into a droplet of molten plasteel, metal in all directions in imitation of the sacred ground of the forge world that had created the Titan.

Six plain columns lined the walls to each side, their fluted capitals merging with the vaulted ceiling. Recesses between the pillars housed murmuring servitors, each no more than a torso and head attached to the wall, their lips in ceaseless motion. Listening carefully, she made out a scattering of phrases from the babble of techna-lingua.

The Eighth is Supreme, being divisible by the cardinal and the binary.

Upon the vox do we hear the voice of the Machine-God rendered mortal.

Unto every Design is laid Wisdom. Beneath every Wisdom lies a Design.

No machine is arbitrary, for in its workings is found the faultless logic of the Omnissiah.

They were all teachings of the Cult Metalica, lessons she had attended since her earliest memory. Much of it she still did not understand, but had learned by rote to honour the Machine-God.

Ghelsa had thought to see white-clad figures attending to the arcane systems of the Casus Belli, but then remembered that they were in the antae, the outer chamber. The louder chanting of techna-lingua came from beyond a doorway at the far end, reverberating along a broad passageway.

She took a step towards the door, eager to see the tech-priests at their stations.

<Halt.> The command came from a servo-skull that floated down in front of her, glaring with an unliving emerald gaze. <Await the magos.>

It drifted away, its suspensor field cutting interwoven vortices through the incense. Ghelsa noticed more servo-skulls close to the ceiling, hovering beneath the vaults. She could not tell if their glinting eyes were active or dormant, or whether any other mind monitored what they saw.

Ghelsa wanted to pace, she was so full of apprehensive energy, but contented herself with adjusting the grip width of the multi-tool. The buzz of its small motor vibrated in her hands as the jaw opened and closed.

‘Is that really necessary?’ said Harkas, scowling.

She threw him a sour look but stopped, his chiding making her feel foolish.

A movement at the doorway drew her attention. A figure swept into the antae borne upon six many-jointed legs that clacked noisily on the hard floor. The body was long and hunched, concealed for the most part beneath layers of pale robes, showing only a flash of segmented metal and dangling pipes as the magos moved closer. Four spindly arms, each within its own voluminous sleeve, waved and swayed as the senior tech-priest advanced.

Ghelsa peered into the shadow of its cowl and gasped. Its face was almost untouched by bionic enhancement, a slender female visage framed by coils of wire. Ghelsa was accustomed to the insect-like masks of the tech-priests and it took her a moment to adjust to the juxtaposition of unadulterated human flesh among the sprawling mechanics.

Dark brown eyes regarded them passively while a tentacle-like appendage fitted with a cluster of artificial lenses slid out from under the robe. A strobing fan of narrow red rays passed over Ghelsa’s face before moving to Harkas’, and then flicked off as the tendril withdrew.

The servo-skull floated over the tech-priest’s shoulder.

<Inconsequential,> intoned the skull as the magos turned away. <The hyperezia have been summoned.>

‘Wait!’ called Ghelsa, taking a step forward. A disturbingly animalistic growl from Delta 6-Terror stopped her taking another. The magos stopped but did not turn back. The servo-skull hovered in front of Ghelsa, uncomfortably close to her face. Unable to bear its scrutiny, she dropped to one knee, her gaze fixed on the floor.

<State your inquiry.>

‘A blessing, revered magos. For a faithful servant of the Machine-God.’

The magos’ claws clicked on the floor as it turned. Ghelsa dared look up, holding her breath. There was no expression on the face as it tilted down towards her on a telescoping neck, no less a mask than the artificial visages of the other tech-priests. She saw tiny reflections of herself in the dilated pupils, the multi-tool clenched tight in both hands, her own eyes wide with pleading.

<Petition accepted.>

The magos beckoned her to approach with a clawed hand. Ghelsa could not help but notice the similarity to her own, as though the tech-priest’s limbs were a version of her exo-skeleton purged of the unnecessary flesh within. She stood within arm’s reach, looking up into the tech-priest’s impassive stare. Dexterous sub-digits extended from the palm of the mechanical hand, flexing as they slithered free. Lubricant glistened on their tips. The magos bent forward, laying the worm-like appendages upon Ghelsa’s bald head, their touch cold but reassuring.

The tributai sighed, feeling relief wash through her as dribbles of oil rolled down her face and neck. This close, the scent of the magos’ incense was almost overpowering. It stung Ghelsa’s eyes and cloyed in her throat, both enriching and unwelcome. The tendril-fingers moved forward to the cog upon her brow and she felt a quiver of connection. Thought-packages fired across her synapses, leaving their message burned into her thoughts.

{The Will of the Machine-God moves within you. You are the Vessel, the Omnissiah is the Spark. Bear witness to true Faith and remain Pure within the Impurity of flesh.}

With the words came a vision, one of innumerable gears interlaced across the galaxy, some turning fast, others slow, all driven by the same purpose. Stars were cosmic furnaces driving the engine of the universe. Whirling planetary orbits described impossibly complex motions through time and space. Ghelsa was a tiny mote of existence in the infinite, yet despite her minuscule nature she felt like an essential part of the whole.

The cord-digits broke contact and whipped back into the magos’ hand. Ghelsa staggered back, trembling from head to foot. The magos turned away, limbs retracting within the robe. The image of the cosmic engine started to fade and Ghelsa tried desperately to sear it into her memory, to capture something of its eternal grandeur. The harder she tried, the more she fixed upon a detail, the more she forgot of the rest, until she was left with nothing but a vague sense of ceaseless motion.

The magos had gone, though the servo-skull remained, its dispassionate stare fixed upon her.

<Praise the Machine-God,> it declared.

Ghelsa hung her head, her shoulders slumped, elated but exhausted, joyful yet empty.

‘Praise the Machine-God,’ she whispered, a tear rolling down her cheek.

Chapter 9

Victory and Defeat

<Your escort has arrived,> declared the servo-skull.

A few seconds later the sub-door wheezed open. Three men and two women stepped inside. They wore cloaks lined with red cloth over grubby coveralls and carried long mauls. Two of them had bulky laspistols hanging on simple holsters at their waists. Ghelsa didn’t recognise any of them as from the group that had attacked Harkas, but she could barely remember what had happened with everything that had taken place since. Perhaps they didn’t know she and Harkas were being hunted.

The glares they directed at Harkas and Ghelsa told a different story.

‘We’ve been looking for you,’ said one of the gun-wielders, tapping her club against the side of her leg. ‘Didn’t expect to find you up here on the holy decks.’

‘Hereteks,’ sneered another. He looked directly at Ghelsa. ‘The ingratitude makes me sick. To turn on the Legio like that?’

‘You’re fortunate,’ said the one who had spoken first – her cog-badge clasp identified her as the leader. She pulled something from a pocket, a slender silver chain from which hung a pale wooden box about the size of a thumb. An ‘I’ with two bars across it was branded into the front. ‘The Inquisition would do far worse for impersonating one of their order.’

Ghelsa looked at Harkas. ‘Is that it?’ she said, unimpressed. ‘That’s your sigil?’

‘It is the authority it conveys that has the power,’ he replied testily. He stared at the hyperezia with narrowed eyes. ‘If you comprehended the magnitude of your error you would beg now for forgiveness and swift release rather than face the torments that will surely follow this treachery.’

The one who had spoken first beckoned with her club. ‘Move your filth out of these sacred halls.’

‘Delta 6-Terror, what is the status of our faithfulness?’ asked Harkas, looking up at the warbot.

<The two unidentified combatants are faithful.>

‘Stop talking to the holy warrior,’ snapped one of the hyperezia. ‘Your interaction defiles its spirit.’

Harkas stepped towards the door and motioned for Ghelsa to follow.

‘Hostile forces are still at large in the akropoliz,’ he said. ‘The faithful require protection.’

<I will provide protection to the faithful,> rumbled Delta 6-Terror, following with long, slow strides. <Destroy. Secure. Protect.>

From the rear rampart of the akropoliz, Exasas looked back at the surrounds of Az Khalak. It was only from this vantage point that the light differential over the city and the surrounding hills could be so clearly seen. It reminded Exasas of a stellar eclipse, standing in darkness while viewing beams of light in the distance.

With augmented vision ve could see the accompanying host of the tech-guard flowing into the city and through fortress walls. Ve was too distant to detect any noospheric activity, but the occasional spark of brightness betrayed a plasma shot or other high-powered discharge, indicating that the rebels had not yet been eradicated. While vanguard battalions and companies of rust-stalkers cleansed the ruins, squadrons of ironstrider-mounted dragoons and ballistarii pushed out into onto the slopes of the flanking mountains. Slower columns of quadruped dunecrawlers followed, providing escort to tracked bulk-carriers.

The smaller streets restricted the progress of the knights, so that the warrior-machines of House Raven were confined to a perimeter in the outskirts while their smaller suits patrolled along the main arterial routes. The flare of an activated ion shield here and there betrayed the last desperate counter-attacks of Az Khalak’s defenders.

Exasas watched the blur of six skyspears as they raced past the broken towers of the citadel, aptly named for their sleek but prow-heavy design. Their nose cones still glowed red hot from orbital entry. Exasas tracked their trajectories and calculated that they would arrive within the next forty-five seconds.

Ve had not been idle during the wait, and had accessed every datalog entry ve could find concerning the new arrivals. There seemed very little about them, given that the Krysaorian League was one of the more powerful blocs of Metalica, an alliance of fourteen forge cities and a member of the inner council. Exasas had noted with some exasperation that they were not part of the tech-guard proper but had been attached as auxilia to the formation shortly before the Legio departed for Nicomedua. Most of their previous engagements were cipher-locked, and Exasas could not discern any reason why that might be so.

But it was not vis position to judge the incoming magos; vis position was to ensure a cooperative defence of the Casus Belli. As the princeps senioris had so curtly pointed out, all personal considerations were secondary to that duty.

Even so, negative fluctuations affected Exasas’ cogitations as ve observed the skyspears slowing, their gravitic repellors gleaming purple in the heightened air static of the storm front. Descent jets cut out and the dropcraft slid towards the Casus Belli as though lifted by the glow of their repellors.

Four of the skyspears pitched towards landing points not far from the leg bastions while the remaining two halted their descent on a level with the akropoliz. Engines humming, they buzzed over the magos dominus, missing the upper towers of the akropoliz by a small margin, and slewed rapidly to a stop over the frontal apron.

Exasas hurried around the side of the akropoliz and came upon the main parapet as the skyspears touched down, the pulsing of their repellors pushing pools of still-wet blood into crimson rivulets across the ferrocrete. Attitude jets burned bright, keeping the two craft hovering just over the parapet while their bellies opened up, the bright glare from their interiors lighting the blood-spattered courtyard.

Disembarkation ramps extended like unrolling tongues of metal, their corrugated lengths flattening against the rampart. Their angled portions hardened into steps and the first of the augmentatii descended into view.

Moving out of the antae, Ghelsa discovered that the atrium was thronged with skitarii soldiers. Mindless servitors dragged away the bodies of the dead while tech-priests performed inspections of broken automata, performing last rites where needed before salvaging the datacores. Ghelsa’s attention was drawn to a tech-priest with dozens of spindly limbs opening up the armoured shell of a battle-construct. A las-suture played over the pulsing cortex within, repairing input to the organic brainstem.

<They will be reborn,> intoned Delta 6-Terror. <The Machine-God presides.>

Surrounded by the hyperezia, they were led up the first flight of stairs and into the corridors towards the aft chambers of the akropoliz. The leader hastened them on, but Harkas hung back with the slower-moving battle-construct, much to her annoyance.

‘Delaying isn’t going to help you avoid what’s due,’ she said, jabbing her maul towards the inquisitor. ‘Justice is coming soon.’

‘And what form will this justice take?’ asked Harkas.

They turned into a smaller corridor. Bodies were piled high on one side, stripped of uniform and wargear. A door at the far end led into a chamber that glowed with flame light. Tracked servitors rumbled in and out, lifting up the bodies to take them inside.

‘The incineratorum,’ said Ghelsa. ‘That’s where you’re going to do it?’

‘Do what?’ asked Harkas, though it was obvious what he planned.

‘There’ll be no more heresy from you,’ one of the hyperezia said with a grin. ‘Just flesh-smoke and bone-ash.’

‘I think you should suffer first, but the moderatus prime said to get it done quickly,’ said the leader. ‘Nobody’s going to rescue you this time.’

They were halfway along the passage. Ghelsa clamped a hand over her mouth and nose to keep out the smell of blood and escaping bodily fluids, a stench even the incense-memory of the akropoliz could not mask.

‘What are you going to do to us?’ Harkas demanded loudly. He glanced at Ghelsa and tilted his head towards Delta 6-Terror.

‘No, that’s not what I meant,’ said Ghelsa, realising what the inquisitor intended. She looked at the leader of the hyperezia. ‘Don’t answer him. We’re under the protection of the kastelan!’

‘Save your breath,’ the leader replied. ‘You’re hereteks and you deserve to die.’

‘Are you going to do it?’ snapped Harkas. ‘How? What are you going to do?’

‘Don’t say anything!’ Ghelsa stopped and turned to Harkas. ‘We can warn them.’

‘We’ll do it quickly, like the moderatus prime told us to,’ said another of the hyperezia. He flicked greasy hair out of his face and patted his laspistol. ‘We’ll shoot you and dump the bodies in the incineratorum.’

Delta 6-Terror stopped and raised the phosphor blasters in its fist. The combustor over its shoulder twitched as it targeted the hyperezia.

<Threat detected.>

‘Just go, say nothing,’ Ghelsa urged them.

Harkas tugged at her arm, pulling her back from the kastelan’s line of fire.

‘They are hereteks,’ said the hyperezia leader. ‘We are going to execute them.’

<Faith status established. Insufficient authority to alter faith status.> Delta 6-Terror’s weapons tracked the enforcers as they backed away, gathering closer to their leader.

‘They are the hereteks,’ shouted the one with the laspistol, his empty hand moving to the weapon’s grip.

‘No!’ Ghelsa tried to step forward, but Harkas wrenched her back.

<Threats to the faithful are unfaithful. Defence protocols initiated. Destroy. Secure. Protect.>

On first examination the new soldiery appeared little different from the other tech-guard of the Legio. They wore the signature white coats of Metalica and displayed an array of gunmetal bionics. There were small visible details, insignia and edgings of coats and robes, that marked them out from Exasas’ own warriors, but a far more telling difference was the noospheric aura that surrounded them.

It was a dense mass of continual exchange, as dark to Exasas’ probing as the thunderhead that covered the valley behind them. The crash of boots on steps and then ferrocrete was near perfect, as was their mustering in squads in lines facing their transports. A surge of noospheric activity preceded weapons simultaneously lifted in salute to the emerging magos.

It seemed a needlessly inefficient display, and Exasas was unsure whether the benefit was meant to be vis or the accompanying dominus’. It hinted at unresolved issues of ego. To Exasas authority was self-evident and required no such ostentatious behaviour.

A strange thought distracted ver. Ve wished that ve had donned vis warskin for the encounter. Ve had decided against that course of action on the grounds that Exasas-tactical would not be best placed to integrate the strategic needs of both skitarii forces, and the warskin was still undergoing repair. Looking at the newcomers’ gleaming arc rifles and unsullied uniforms, Exasas concluded that a greater physical presence might have been of benefit in the exchange that was to follow.

Chastising verself for such nervous meandering, Exasas wondered why the other magos delayed their arrival. Were they receiving instruction or simply testing Exasas’ patience in order to exert some greater authority? The magos dominus was tempted to depart as a signal of contempt for the unnecessary hesitation, but opted to remain on the grounds that it might be interpreted as ceding command.

A blue tint touched the light from the closest skyspear and a second later the augmentatii’s magos dominus slid into view.

The cerulean glow came from the circle of suspensor units that splayed from the magos’ circumference like a planetary ring. The greater part of Magos Dominus Exceptis Keterina-Ga Skitara Syntamatarkias Olvatia was a horizontally segmented sphere held inside the suspensor toroid, with a mane of long, slender sensor tendrils undulating across the upper hemisphere. Exasas was surprised that vis fellow magos had travelled outside of a warskin, as it was immediately obvious that Olvatia’s form had even less combat potential than Exasas’.

The noosphere throbbed like a heartbeat at the approach of the other dominus, the magos exceptis’ presence bending it like a mass on a space-time gradient, absorbing the dataflow just by existing. An audible hum accompanied Olvatia’s progress while a forced binaric shout issued from the grilled mouths of the attendant alphas. The noosphere contorted with the exhortation, signalling the dominus’ arrival to the tech-priests within the Casus Belli.

Five more Krysaorian tech-priests emerged from the command transport a few seconds after their magos, as diffuse in form as any Exasas had encountered – two hunched humanoids, the other three far less easy to categorise with their many-jointed limbs and articulated mechadendrites, swathed in white-and-red robes.

Exasas interposed verself between Olvatia and the antae of the akropoliz. The other magos drifted to a halt just out of reach and the segments of the upper hemisphere of the main body slid backwards a quarter-arc, revealing Olvatia’s pinched, bionically grafted face. A swift analysis of the underlying bone structure confirmed a female-origin humanoid, though Exasas new better than to make identity assumptions based on such transitory physical details. Only the skull, brain and nervous system tissue remained. A waxy fakeskin covered the remains of Olvatia’s head and face, embedded crystal orbs glimmering from the sockets. The fakeskin folded awkwardly as partially inflated lips approximated a smile.

‘Pleased to make your acquaintance, Magos Dominus Militaris Xaiozanus Skitara Xilliarkis Exasas.’

A noospheric datapoint tagged Exasas’ processors to exchange security and identity protocols. Among the swift burst of traffic was a standard persona construct package.

#she/her/her/hers/herself#chronoglacial#binaric#olvatia#noospherent2918721#

Exasas noted that Olvatia still identified with her female origins despite the almost complete lack of physical resemblance to the person she had been. Occasionally a high-ranking tech-priest would shed such identifiers, but it was striking how lasting such early self-views persisted beyond the flesh. Vis own genderless identity was extant from vis first cogent thoughts, a part of vis self-determination even before any abstraction of vis physical form. Ve responded in kind as ve extended an appendage in greeting.

‘Welcome to the Casus Belli, Magos Dominus Exceptis Keterina-Ga Skitara Syntamatarkias Olvatia.’

#ve/ver/vis/vis/verself/#chronotangent#binaric#exasas#noospherent4458947-e#xilliarkis#

They regarded each other with a full suite of pseudo-physical and digital senses, the noosphere purring between them with assessment vibrations. Exasas was determined that ve would extend no further invitation unless a formal request was made, and it seemed that Olvatia was equally adamant the current magos dominus should cede command directly.

The standoff was interrupted by a sudden motion from the Casus Belli. Exasas broke off from vis rival and hurried to the frontal parapet. The last of the relief augmentatii were racing up the steps of the port bastions, those within the starboard already secured as the foot started to lift. Ve swung back towards Olvatia.

‘The princeps senioris is keen to avoid delays.’ Ve measured vis next words and opted to voice them as suggestion rather than command until the matter of hierakos was unified between them. ‘You should deploy your troops within so that we can secure the akropoliz.’

Olvatia did not reply immediately, and Exasas suspected she would try to force the issue of dominance. Instead she extended a noospheric frond to his receptors.

Olvatia [conciliatory]: <Sympathies for your loss of personnel. A fraught time for all – let us endeavour to raise ourselves above personal ego for the betterment of all.>

It seemed a strange thing to say, effectively suggesting that they ignore the protocols of hierakos. Exasas toyed with the idea of exerting vis position more strenuously, but in an effort to maintain amity, ve did not argue the point.

Exasas [conciliatory]

Ve undulated alongside the other magos and extended a limb towards the open gateway.

‘My alphas and battle-priests are keen to integrate our conjoined forces.’

A noospheric pulse from Olvatia had the augmentatii running to the gate a second later, followed more serenely by the two magi.

As the battle group headed into the storm-wreathed valley the interference grew stronger. Arcs of scarlet fire played across the void shields, each lightning strike rippling coruscations of bright purple and white about the Titans. Dark hail started to fall, some of the stones as large as fists. They posed no threat to the armour of a war engine, but soon the constant drumming became an audible counterpart to the static-crackle that beset the noosphere and vox-links. Wherever Exasas extended vis senses, be it biological or digital, a numbing drone greeted ver.

Visibility was similarly impaired. In the gloom beneath the immense thunderhead, storm lamps lit the way, their beams seeming to flicker in the monumental deluge. Datafeeds sputtered and stalled beneath the onslaught of electromagnetic discharge and feedback surges rattled into the magos’ system like impact vibrations.

Ve had returned to vis monitor station to witness the Casus Belli’s entry into the stormfront, but doing so had meant leaving Olvatia alone in the akropoliz. Between the intermissions inflicted by the storm activity and the augmentatii proprietary cipher channels, it was impossible for ver to study exactly what the new arrivals were doing. Exasas was forced to use visual and auditory feeds from across the Titan to supplement the intermittent noospheric data, which was a time-consuming process.

A few minutes after crossing the outer boundary of the tempest, they lost contact with the rest of the battle group. Like sparks whirled away on a hurricane, the noospheric signatures of the other Titans disappeared, leaving the Casus Belli to forge along with only the glimmer of their lamps to signal their positions.

Monderas: <We can draw reassurance that whatever besets us, it is equally difficult for any foe. The elements are our only enemy for the present.>

Exasas did not agree, but chose not to voice any doubts. The matter of vis continued command rank had not been brought up again since the arrival of the new skitarii contingent, but ve was of no mind to draw attention to verself in the eye of the princeps senioris.

Iealona had been silent since Exasas’ return to the czella, an absence of communication easily explained by the need to focus all of her effort on guiding the Imperator through the storm. In contrast to Monderas’ attempt at positivity, Exasas found verself drawn into a declining morale gradient by the thought that their uninterrupted advance served the purposes of the enemy more than their own. If vis conclusions that the traitors had been attempting to weaken the rest of the battle group were correct, the isolating influence of the electrical tempest furthered that end.

Risking a repeat accusation of data-paranoia from Monderas, the magos connected to the surveyor systems and ran vis own analysis as a redundant process. The dataflow was painfully sporadic, utterly non-existent in some quadrants during particularly excessive storm discharges. Even the lamps of the other Titans had become almost invisible in the darkness, so that it seemed the Casus Belli advanced alone through a tunnel of blackness lit only by the reflections of light from the curtain of hail.

According to the archive logs there were old settlements dug into the mountains on either side, storm-shielded to protect the inhabitants from just the kind of elemental rage that currently engulfed the valley. There was a significant probability that the enemy were using those subterranean dwellings at that moment, poised to attack when the storm’s fury abated.

A worrying track of logic drew Exasas into further extrapolation. If the hereteks were ensconced within the mountains in any conflict-viable numbers, they might mount a problematic counter-attack against the forces securing the remains of Az Khalak. Devoid of the battle group’s considerable firepower and yet to establish their own defensive positions, the tech-guard were vulnerable to a rapidly launched assault.

Exasas: <We have made a strategic error in separating from the skitarii echelon. We must halt and rectify the disparity.>

Monderas [interrogative]: <I calculate the current threat to the battle group as close to zero. Explain.>

Exasas: <The threat is not to the god-engines but to our tech-guard. We have fallen foul of Haxaffa’s First Principle.>

Gevren: <That coordination of labour comes prior to division? What a curious analogy, to compare the majestic Titans of the Legio to toil shifts of a manufactorum.>

Haili [injunctive]: <Not curious, insulting!>

Exasas: <The comparison remains. Haxaffa posited that overseers risk inefficiencies by placing their requirements above those of the process they must guide. Though the axioms he created were derived from the production chambers of the forges, they have been attributed universality by the Metalican council and hence can be representative for all forms of endeavour.>

Gevren: <Your meaning is still opaque, Xaio. Don’t use complexity to affect false wisdom – speak plainly.>

Exasas: <As command officers of the battle group, and in particular the Casus Belli, we are comfortable creating a strategic paradigm with ourselves at the centre.>

Monderas [intercessionary]: <As the single most powerful element in the battle group that is logical. Our performance is the greatest concern.>

Exasas: <Though as a single entity we have the greatest impact, we are not greater than the sum of the remaining parts. This reasoning extends to the battle group. We consider the Titans in light of their mission and the skitarii as support to that.>

Gevren: <Your bias is evident. Skitarii are expendable, Titans are not. As dominus it must be hard for you to accept that, but you must. Even you, Magos Exasas, are secondary to the good of the Casus Belli.>

Exasas [emphatic]: <Absolutely. And the Casus Belli is secondary to the good of the battle group. By extension, the battle group is expendable in the cause of the entire campaign, should it be necessary.>

Monderas: <That is debatable. Like skitarii, new Astra Militarum resources can be raised. Not even ten regiments require the effort to create that which has been invested in the Casus Belli.>

Exasas: <From the outset the raising of Imperial Guard regiments has not been an issue, but their deployment has. Though not irrelevant, that is secondary to my argument. In the matter of holding Az Khalak the roles are reversed. The battle group is not suited to the function of urban pacification and security.>

Gevren: <And that is exactly why the battle group moves on, Xaio. We cannot waste our time defending street corners against the remnants of the city’s defenders.>

Exasas: <But who would defend the skitarii against overwhelming counter-attack? Our role moved from primary to secondary at the instance of the city’s capitulation. At every encounter thus far the enemy has demonstrated a carefully staged defence. What if they engaged in a subterfuge that allowed them to feign greater strength within the city than actually existed, instead marshalling the forces we thought within Az Khalak in the highlands? Having realised that they could not hold the city, the prudent course of action would be to evacuate such forces as they could for future use. And if in doing so they could convince their attackers that their strength was broken, they would pave the way for a potentially successful counter-offensive.>

Iealona: <Do you have any alternative, dominus?>

The sudden emergence of the princeps’ senioris presence surprised Exasas, as did her question. Ve sensed a flurry of moderati-princeps traffic across the distorted noosphere. Although it was a direct contravention of hierakos, the pattern suggested that Gevren and the other moderati were exerting undue influence over their superior. If there was a moment for Exasas to reiterate vis case, it was now. It was vis duty to challenge the logic of the others, but with another dominus on board Exasas felt insecure in vis position of command.

Ve hesitated, keeping vis fears to verself.

Iealona: <There can be no retraction of our current orders, dominus. We are in communications blackout with the battle group – we must press on to the rendezvous beyond the storm.>

And with that pronouncement, all further discussion was thwarted. Against Exasas’ grave misgivings, the Casus Belli would press on.

An insistent signal through the static of the noosphere finally drew Exasas’ attention. It was a latent communication from Olvatia that had been inserted during their first contact, time-coded to not make itself known immediately. Exasas treated the data-packet with suspicion, just the latest in a series of increasingly unorthodox occurrences that had beset ver and the Casus Belli since they had started their attack on Az Khalak.

There was a pattern to be discovered, ve was sure of it. Ve could see the edges – the extant facts of the enemy’s behaviour and the spiralled intertwining events that had brought the battle group to its current status. Yet no amount of examination revealed the hub that connected them. Exasas knew well enough that the centre was not only the end point of the calculation – it was also the beginning. Ve knew that if ve could decipher the meaning of the enemy’s actions and properly extrapolate them to a defined outcome, there would be an evident counter to it.

There were other, more disturbing factors to take into consideration. Facets of the moderati’s behaviour – perhaps even Monderas’ – that raised more questions. The arrival of the other magos dominus possibly implicated some sort of politicking at the Legio command level.

It was not unusual, though less common within the Legio than the wider Cult Metalica. The demands of hierakos and the ambitions of individual magi meant factionalisation was inevitable. In some social models it was even deemed desirable, though as a strict militarist Exasas viewed dissent and internal competition as inefficient compared to cooperation against external threat.

Although it had probably held back vis progression into the higher ranks, Exasas had previously remained explicitly neutral in such affairs. A power struggle within the upper echelons of the Legio Metalica would explain some of the idiosyncrasies of their current deployment, but the magos dominus was determined not to be drawn into it on account of it being a distraction from completing vis theorem.

The time capsule attracted vis attention again, with increased vitality. Still unsure, Exasas created a sub-persona to engage with the message, shielding the greater part of verself from contact. Sub-Exasas accessed the data-stub with the care and circumspection of a surgitas trying to remove an unexploded bolt from a patient.

#security.of.casus.belli.compromised#immediate.action.necessary#consultation.required#auditory.exchange.only#main.battery.magazine#

The message confirmed Exasas’ opinion that the crew of the Casus Belli were being subjected to an unseen manipulation at the cost of operational effectiveness. As an outsider Olvatia had an ideal perspective to determine these irregularities, although the clandestine nature of her communication did not bode well for any ambition on her part to bring the issue to light with the rest of the command crew. It was reasonable to assume that she wished to pass on whatever information she had to Exasas to avoid becoming embroiled herself – although her presence on the Imperator was already evidence that she was unwittingly involved.

Even so, the promise of further data on the subject was sufficient to temper Exasas’ suspicions. Ve registered vis desire to depart the command module. Though ve needed no justification to do so, ve felt the need to provide an excuse. The lie came with shocking ease.

Exasas: <I must attend to the deployment of my troops around the main battery to ensure no repeat of the renegade Space Marine insertion is possible.>

None of the others responded, so Exasas disconnected the physical links to vis station and departed without further comment.

The corridor filled with noise and brightness as Delta 6-Terror opened fire. Burning rounds from the phosphor blasters hammered into the hyperezia, setting fire to clothes and flesh with intense bursts of whiteness. Their screams were drowned out by the din as the battle-construct’s salvo continued, round after round tearing apart the hapless servants of the Machine-God.

All bar one of them collapsed straight away, riddled with burning holes where white flickers of flame still danced. That one survived to flail down the corridor, clothes ablaze, his screams pitched higher than any sound Ghelsa had imagined a human could make.

The hiss of still-burning projectiles sounded disproportionately loud in the quiet that followed. Fat sputtered amid steaming vapours, accompanied by the thud of a twitching boot or slap of a hand spasm. The stench of charred flesh mixed with the already noxious odour of the skitarii bodies, and in combination it was too much for Ghelsa. She staggered to the wall and vomited, her legs weak beneath her. She trembled, only the exo-skeleton keeping her upright as she retched again, her bile acrid with incense aftertaste.

‘You…’ She took a breath and leaned her head against the wall. The pressure against her brow-cog helped cut through the fog of her thoughts. ‘You could have warned them.’

Anger flared. She whirled on Harkas, multi-tool raised. He shook his head, his eyes widening, and it was only as Delta 6-Terror started to turn towards her that she realised her mistake. She let the metal fall from her fingers to clang to the floor, stepping back with her hands over her head so that she presented no threat.

She stood like that for several seconds, fixing Harkas with a venomous glare. The click of servitor tracks drew her eye back to the incineratorum. They laboured without interruption, dragging away bodies. One of them raised its head, saw the freshly slain hyperezia and cruised down the passageway towards them, claw-arms outstretched.

‘You should have warned them,’ she said again. ‘They would have had to let us go.’

‘Or summoned a magos or officer with the authority to revoke our faith status.’ He frowned. ‘This was your intention, not mine. I wanted to esc–’

He glanced at the warbot and evidently decided against finishing the sentence.

<Mission parameters incoherent.> The monotone statement took them both by surprise, halting any further argument. Delta 6-Terror seemed locked in a quandary, pivoting towards Harkas and Ghelsa and then turning back towards the atrium. <Incompatible determinations.>

‘You were commanded to deliver us to the hyperezia,’ said Harkas. He stepped over the burnt corpses and retrieved the two laspistols. He offered one to Ghelsa, but she declined with a shake of her head. ‘You have achieved your mission.’

The automaton pointed a blaster at the smoking remains.

<Hyperezia are non-functional. Mission parameter incoherent.>

‘Your mission is to protect us,’ Ghelsa said quickly, realising the potential of having a kastelan bodyguard.

<Mission is to protect all faithful.> Delta 6-Terror straightened, arms at its side, and ceased its oscillations. <Destroy. Secure. Protect. I will seek parameter clarification from Datasmith Undra.>

The construct stomped along the passage back towards the atrium. Harkas put a finger to his lips to quieten Ghelsa as she opened her mouth to call after it. A slight shake of his head silenced her protest of his dismissive gesture. When the machine had turned the corner into the connecting passageway, the inquisitor let out a long sigh.

‘It is better for us that it doesn’t think we are still in custody,’ he explained. ‘At least we will not get shot for taking a wrong turn that it interprets as us trying to escape.’

Harkas returned to the bodies and pulled his sigil from the hyperezia leader’s grip, breaking off a charred finger as he did so. He held it up, his expression similar to Notasa’s when he had not seen Ghelsa in too long. Thoughts of her fellow tributai spurred a sudden sickness in Ghelsa. Though only a few hours had passed since she had first seen the inquisitor, it felt as though she had been away from her people for an age.

‘Go,’ she said, retrieving her multi-tool.

Harkas looked at her, contemplative, and hung the chain around his neck.

‘Go?’ he said. ‘What do you mean?’

Ghelsa pointed at the Inquisitorial badge. ‘You can complete your mission now.’ She turned her stare back to the corpses of the hyperezia. ‘I’m done with this murder.’

Chapter 10

Powerless

To expedite vis progress to the higher levels of the akropoliz, Exasas sped to one of the vertical conveyors that had been shut down during the boarding attack. Ve summoned the car with a noospheric broadcast and likewise set the container into motion for the battery level after ve had curled vis form into its cage-like interior.

As ve ascended ve could see as well as sense Olvatia’s augmentatii spread around the akropoliz. Ve had counted one hundred and forty warriors disembarking from the skyspears and assumed a similar number had entered each of the bastions in the lower legs. Four hundred and twenty skitarii soldiers were nearly one hundred more than ve had commanded at the outset of the campaign, and quadruple the troops now at vis disposal.

It occurred to ver as the conveyor slowed towards its destination that ve should demand the noospheric access codes for the League soldiery. Through the authority of hierakos ve was the Imperator Dominus, and all battle-priests and skitarii personnel were vis to command.

Ve resolved to request – demand! – that right when ve spoke with Olvatia. If she was unwilling then ve would seek the authority of the princeps senioris, and ve would either be vindicated or would stand down. The noncommittal nature of the current arrangement was unacceptable.

Thus roused, Exasas ushered forth from the conveyor into the corridors around the immense turntable and gun tower of the main battery. There were more of the League augmentatii here, stationed at the gateways that led to the main battery and the flanking secondary gun towers, and a demi-squad outside the reinforced doors of the magazine itself.

They stepped aside to allow Exasas to enter, but closed ranks as soon as ve had passed within. Ve wondered if it was too late to summon any of vis own soldiers but decided that paranoid escalation would be seen as a sign of weakness rather than strength. Ve did not need to rely on such psychological trickery – ve was dominus by right of hierakos.

The magazine would have been a four-storey building in any other circumstance, consisting of an outer shell and the inner vault. The autoloader shaft ran from the centre of the vault chamber to the main battery above. Numerous arched windows with glass stained with scenes from the calendar of the Cult Metalica decorated the outer wall, which was lined by a shallow rampway that wound about its interior.

The flashing light of the storm cast Olvatia’s oval shadow from about halfway up the frontmost wall, hovering in front of a window triptych that displayed the Culmination of Disentropic Labours.

Exasas tried to extend a noospheric handshake but was met with a feedback shriek from a suppressive field. Recoiling, ve remembered the injunction for auditory exchange only.

‘I have no desire for subterfuge,’ Exasas announced as ve started up the ramp.

‘Nor I, magos,’ Olvatia replied. ‘It is for that reason and consideration for your prior service that I requested this interface.’

‘Prior service? I think you mean current service, as I am still Imperator Dominus of the Casus Belli.’

‘If you wish to remain so, then you must listen to me carefully.’

‘I analyse all inputs with equal rigour.’ The turn of the rampway took Exasas out of sight of the other magos, but her voice drifted back down the magazine hall.

‘Your literalism has held you back, and now I see why. You fail to embrace all of the routes to Higher Wisdom.’

‘What you choose to mark as a failure I see as a strength. Rather than split my efforts across many journeys to enlightenment, I have focused upon a narrower path with utter dedication.’

Ve reached what would have been the second storey to find that Olvatia had floated down towards him along the ramp above and opposite his position. It was vexing to rely upon only short-ranged physical scans, but ve boosted vis suite of sensors to compensate for the lack of noospheric interaction between them. Ve heard the subtle whisper of the suspensor motors as Olvatia came closer.

‘Then why have you not elevated yourself further in your time?’

‘I think you are poorly qualified to lecture on the merits of achievement, Olvatia. Your service is disparate, uncharted. You have no great standing in the Cult Metalica that I can discern, though I have looked for some reason that explains how you have attained the rank of dominus.’

‘I can help you, Exasas.’ She stopped a few metres ahead of ver and ve halted also. Olvatia’s hair-sensors bristled upwards, though Exasas had no means or experience to interpret the meaning of the display. ‘More importantly, I can help you to help yourself.’

‘You said that the security of the Casus Belli was under threat. I have surmised as much from the activity of late. What is your perspective on this phenomenon, and are you willing to make an alliance to rectify the situation?’

‘I am surprised – I thought you would be ignorant of what was happening, and I certainly did not foresee that you would wish to add your support to the cause. Perhaps I have underestimated you.’

‘I have not yet identified the cause to which you refer, Olvatia. It is obvious that two or more blocs within the Legio command echelon are in conflict and that the Casus Belli and its skitarii cohort are somehow implicated. I do not know nor care to know the individuals involved, only to ensure that it ceases imperilling the Casus Belli. Not only the Imperator but the battle group and the entire war effort as well are at risk if we do not return to Az Khalak without delay.’

‘Az Khalak? A small consideration in the greater scheme, confined to this one world. The Casus Belli represents a far more prominent instrument of power. Perhaps your role as skitarii dominus blinds you to the influence one can wield with the aid of an Imperator Titan, as you are such a redundant part of its operation.’

‘The Casus Belli would have been destroyed only hours ago if not for the presence of my skitarii.’

‘Your skitarii? Arrogance as well as ignorance, I see. You command only by the sufferance of your superiors. They are not your warriors – they are the defenders of the Casus Belli. If I were to command them the Imperator would be no less secure.’

Exasas searched for an argument to refute her assertion but was forced to concede the point, vis appendages drooping in acquiescence to her logic.

‘The role of dominus is essential, not the incumbent,’ ve conceded. ‘By that same logic I am as apt to fulfil the rank as you, preceding on the basis that this meander is a precursor to your demand that you assume the title of dominus.’

Olvatia drifted a little closer, frond-sensors tilting towards Exasas. Ve edged back, wishing to maintain the distance between then.

‘Your assumption is correct,’ Olvatia said.

‘Not an assumption – a presumption based on available data.’

‘Your inability to assume is one of your greatest drawbacks. I have seen your datalogs – you have removed all organic brain material yet maintain other elements of your old body. It is a very peculiar thing to do, and it hampers your strategic oversight. You lack imagination.’

Exasas shook the lensed apparatus that served as vis head.

‘You are mistaken. All action is governed by rules, even philosophy and human psychology. Imagination does not exist except as justification for illogical inferences.’

‘There is a place where logic does not hold sway, where the imagination creates rules rather than bending to them.’ Her voice was hushed, barely audible against the vehemence of the storm pounding the magazine windows. ‘Limitless potential, Exasas. Total freedom.’

‘You speak of the warp.’

‘I do. For millennia our kind have studied the Empyrean, trying to unearth its principles, to discern data from madness, structure from the unstructured. It is folly to analyse the warp – one must instead embrace it.’

‘This is the benefit of your imagination? To fool yourself that the energy of the warp can be a companion rather than a slave? No, the warp is anathema to the Machine-God. It exists only to be exploited, not befriended.’

A sigh issued from the other magos’ speakers. Her body tilted backwards as though looking up at the lightning that flashed multicoloured through the stained glass.

‘The warp is spirit incarnate, Exasas. We have enslaved the souls of countless trillions to the Machine-God. What if I told you that the Omnissiah had sought another way, so that the warp and humanity might have been equals?’

‘I would say that you have confused fable for fact.’

Olvatia’s sense-hairs stiffened into spikes, an unmistakable sign of annoyance. She said nothing for several seconds, during which Exasas reviewed the exchange thus far in an attempt to predict its trajectory and bring it to swifter conclusion.

‘As I declared previously, I refute your claim to dominus, and I am willing to lay the decision upon the judgment of the princeps senioris.’

‘Iealona will judge in my favour, but it is not going to come to that. You are going to comply with my demands – logic dictates it.’

‘How so?’

‘I am willing to use force to achieve my ends, even against you and your skitarii.’

She did not have to say more. At the instant Olvatia announced her willingness to engage in violence, Exasas had started four separate simulations based on the data ve currently had access to. All of them ended swiftly in defeat for vis soldiers. Ve tried three others but the outcome was unchanged. Only the severity of the fighting and loss of life varied.

‘Your victory is an absolute certainty, but I can make it costly for you.’

‘You will not. Conflict between our forces only weakens the defence of the Casus Belli. Lives expended in our dispute are wasted. Knowing the outcome, it would be illogical to expend your soldiers – one might even say it would be vanity.’

Exasas’ own calculations had arrived at the same conclusion and verified it several times by the time she had finished talking. Only one question remained, a selfish one.

‘What is to happen to me, Olvatia?’

The League magos slid through the air on gentle pulses of suspensor energy, trailing blue vapour. This time Exasas allowed her to close almost within reach. Ve puffed out a cloud of red incense, a last assertion of independence.

‘You will divert all of your command codes and skitarii access systems to me and officially denote my appointment as Imperator Dominus.’

‘Of course. The defence system must be unified.’

‘What happens after that is your choice, Exasas. You can serve as Imperator Secundus to me, or remain here under guard for the time being.’

Exasas extended vis sensor screen towards the armed figures at the magazine door below. With the noospheric jamming in place ve could not summon vis own warriors to affect a rescue.

‘There is a third option,’ said Exasas. ‘I decline to cooperate and you must kill me.’

‘That would be a waste, Exasas. For all your simplicities, you are an experienced war commander who would continue to be useful to the Casus Belli. The resistance would be futile, as your demise would defer command status protocols to my systems.’

Olvatia pressed forward, forcing Exasas almost against the wall to allow her passage down the ramp. Her tendrils focused on ver as she passed, like filaments drawn to a magnet, but she did not alter orientation or direction.

‘I thought your appearance was a collateral incident of this affair, but I see now it is part of the orchestration,’ said Exasas. ‘You have exploited the situation with efficient ruthlessness and left me no option but to comply.’

Exasas extended a data-spike and Olvatia stopped, parting two metallic segments to reveal a matching port. Exasas inserted the relay and partitioned vis command processors to transfer all authority protocols.

It took nearly two seconds for all of the data to be exchanged. Olvatia pulled away, severing the connection with a jolt of feedback. The segments closed and the new magos dominus of the Casus Belli hummed down to the gate without any further word. The doors rumbled shut, the shadows of the augmentatii outside showing for the last few moments before the two thick portals crashed together.

Exasas sensed a change in the light. Though lightning strikes still threw stark shadows from the high windows, those looking out over the front of the Imperator were perceptibly brighter between discharges.

The Casus Belli was coming out of the storm.

Exasas realised that, as of that moment, ve had become irrelevant.

Ghelsa stepped past Harkas, glad of the support of her exo-skeleton for her leaden limbs. She turned into the main corridor back towards the atrium, only dimly aware of her surroundings. On the level above the turntable of a secondary gun rumbled through the floor, but it had been some time since she had felt the thunder of the cannons.

Still she heard the bark of Delta 6-Terror’s phosphor blaster and the crackle of the burning rounds. Pained cries cut short by fresh fusillades punctuated the auditory hallucination.

Listless, she wandered to the atrium, passing a squad of skitarii heading to… She didn’t know where, nor cared. Stepping out onto the landing, the atrium suddenly looked vast, and Ghelsa felt tiny in the space, inconsequential in the grand scheme of the Imperator.

She sat down with her back against a frieze-sculpted wall, the multi-tool across her knees, her hands quivering. Everything Ghelsa looked at seemed out of focus, as if she were looking at it all through a viewing port misted with condensation. The white coats of the skitarii were just a blur. One of them emerged from the corridor beside her, walking with an oddly determined gait.

The scene faded as exhaustion caught up with her.

Ghelsa jerked awake with a grunt.

A quick survey of the atrium confirmed that only a split second had passed – the stairs were still crowded with skitarii and gun servitors.

The tributai stood up, her focus returning a little, a small remnant of meaning left to motivate her. It got her as far as the closest steps and then failed. Where was she going? Back to the downdecks? The hyperezia were still looking for her. Until Ossissiru Harkas revealed the plotters she was a fugitive.

She wondered where the inquisitor was. She recalled the figure that had passed her moments before and realised she had not recognised Harkas. It only took a few seconds to find him again, descending the steps to the lowest floor.

His objective became clear – at the far end of the hall a cluster of tech-priests had convened. One among them stood out, a spherical body hovering a short distance from the floor. She could tell that this one was a magos from the extensive cybernetics and the deferential manner in which the skitarii and other tech-priests carried themselves in its vicinity.

A dominus militaris.

Harkas was about to make contact with the leader of the skitarii, to unveil the conspirators and stop their vile plot. It would take time for the normal hierarchy to be restored and Ghelsa realised that the safest place, relatively, would be close to the inquisitor. Once he revealed himself and the purge began, his authority could protect her.

She started down the steps after him, moving quickly through the thinning numbers as the skitarii moved to the outer reaches of the akropoliz.

Ghelsa was going to call out, to ask the inquisitor to wait for her, but the open space intimidated her. She imagined her voice echoing over and over through the hall, drawing all eyes to her. Cowed by the thought, she kept silent and broke into a jog.

Something else about the situation nagged at her. There was something wrong with the scene in the atrium, but she couldn’t figure out what. It was the first time she had ever been there, so she had no previous experience with which to compare. She slowed to a walk again, trying to work out what was amiss. Her unease started to coalesce into specific facts.

The dominus was a hovering globe-like apparition, not the same commander they had seen outside the akropoliz. The skitarii uniforms were not quite the same as those she had seen so many times before. They wore the white of Metalica, but the style of their coats and the markings on their armour were not the same. Perhaps from a different part of the forge world, she concluded.

This led Ghelsa’s thoughts to another realisation. The dominus was not the same one that had been in command earlier. Unease knotted her stomach as she wondered why Magos Exasas had been replaced, but she dared not call out a warning.

Biting her lip, she hurried after Harkas, not sure what she could do.

The blackness of the storm gave way to a ruddy twilight. Exasas mounted the rampway to the top of the magazine structure, stopping at a series of narrow armourplas windows bereft of decoration. From this observation gallery ve could see the surrounding gun towers of the akropoliz and the view directly ahead.

Clouds swathed the sky, darkness swiftly encroaching. Exasas’ chronometrics told ver that duskfall would be in less than two standard hours. Though the view was limited, ve could see the mountains to either side of a broad plain, a pair of peaks almost directly ahead. Matching this to the cartographic archive, ve was able to triangulate their position to the mouth of the basin known as the Aza Fai Alessa. There was no sign of habitation and, though visual magnification was no substitute for the Casus Belli’s sensor sweeps, the plain appeared devoid of enemy, either on foot or in vehicles.

There were, fortunately, three other Titans of the battle group already waiting. The Warhounds Woundwalker and Sabreclaw stood alongside the Warlord Will of Iron. Outside the storm the air was still and the dusty ground was marked by the Titans’ deep footprints, showing that they had converged from several directions.

Exasas wanted to see if any of the other Titans were in front of or behind the Imperator, but the structure of the carapace fortifications blocked vis view. Ve had accepted vis usurpation by Olvatia as unavoidable, but frustration grew at the lack of data to process. The logic of her argument had been indisputable. Had ve resisted, Exasas would now be defunct, likely system-terminated altogether.

Ve touched a manipulator to the clear armourplas, swiping the tip across its surface with a screech. It did not even leave a scratch. Similarly, the reinforced buttresses holding up the main battery above were impervious to anything in Exasas’ body, and the doorway was likewise reinforced to contain any detonation from the ammunition vault within.

Escape seemed close to zero-possibility. Barring enemy action that somehow breached the massive hall from without – a breach that itself would likely slay Exasas – there was no way for the magos to exit the magazine chamber, and the noospheric jammer prevented any kind of non-physical extension beyond the walls.

Exasas might as well have been left blinded and crippled, such was the curtailing of vis abilities.

All logic urged ver to one of two courses of action. To continue with the submission and await some future opportunity, or to submit fully and join with the cabal of which Olvatia was clearly an important part.

Was ve right to assume their purpose was antagonistic to vis own? Though ve had never vied for exceptionalism, preference or patronage from vis superiors, ve had undoubtedly benefited as much as been hindered by the politics of the upper levels of the hierakos. By her own account Olvatia could have removed Exasas from the equation more forcefully and permanently. It was ego – the thought of being ousted and vis antagonism with Gevren – that drove out any thought of cooperation. Was vis unwillingness to adapt to this new situation the fault, rather than an objective wrong being perpetrated?

Yet Olvatia herself had mocked him for his lack of illogical assumption. It had been her presumption that Exasas would acquiesce without conflict. The very calculations at vis disposal had been turned against ver, and it was this more than anything else that irked Exasas.

Irked?

It was a very human response, but it was the truest. As much as probability suggested that it made little difference which power bloc within the Legio had control of the Imperator, it vexed Exasas on a personal level that they endangered the Casus Belli with their politicking. Though ve had initially arrived as dominus to expand the scope and implement the practical application of vis theorem, ve had absorbed fully the culture of the Titan and was proud of the duty ve had been called upon to perform.

Processors flared into rapid life at this revelation. It was not some organic instinct nor personal disagreement that agitated Exasas. The evidence to hand strongly suggested that Olvatia’s co-conspirators had been willing to risk the safety of the Casus Belli to achieve their aims. In itself this disqualified them from being entrusted with that guardianship.

They did not represent the best for the Imperator and that was reason enough to stop them. From this tiny kernel of contrariness, Exasas’ determination bloomed into full anger.

Ve had not felt – felt! – like this in many centuries. Even the Traitor Space Marines that had attempted to destroy the Casus Belli had not elicited hatred from the magos. Ve could not hate them, for they had simply fulfilled their purpose. On an intellectual level ve had wished them destroyed, but had taken no personal affront at their existence.

Conversely, Gevren and the others had betrayed all of those to whom they had sworn oaths, and all of those under their protection also. Olvatia’s meandering arguments about harnessing warp power made even less sense now, but were indicative of a flawed ideology.

Above all, Exasas railed against the idea that they had not only expected vis logic-induced passivity, but had depended upon it. Had they thought ve would provide more of an obstacle it was unlikely they would have set their coup in motion.

Invigorated by this train of thought, the magos turned vis efforts to the immediate predicament. How was ve going to fight back from vis current confinement?

Ahead, the knot of tech-priests turned at Harkas’ approach. Glinting lenses and multifaceted detector orbs coldly assayed him as they might an ancient circuit. A cloud of servo-skulls attempted to intercept the inquisitor but he pushed through them.

Ghelsa changed course, walking closer but not so directly, her instincts warning her not to get involved. She had done her part – now it was up to Harkas and the dominus to finish what had been started.

She stopped a short distance away. From this position she was not so near that she attracted attention, but close enough to hear the barked challenge from one of the tech-priests.

‘You are ignoring hierarchical protocol, skitarii.’ The tech-priest whipped a mechadendrite in admonition. ‘You do not have permission to approach the dominus.’

‘I have an important message for the dominus,’ replied Harkas. ‘Of grave importance to the Casus Belli and all aboard.’

‘Your concerns must be relayed through the appropriate communication channels, skitarii.’

‘I am not skitarii,’ declared Harkas, brandishing his sigil. ‘I am an inquisitor, and I will speak with the dominus now.’

Ghelsa could see nothing of the tech-priest’s face, but suspected there would be little enough left to betray any emotion even if she could. Despite that, she was able to read the body language easily enough – the sudden stiffening of limbs. She knew that an extension of secondary appendages was often a reaction to peril.

On occasion she had met with those outside the Cult Metalica – Imperial Guardsmen, Imperial Navy personnel and the like. They always laboured under the misapprehension that tech-priests were only machines, incapable of emotion. Ghelsa knew well enough from her own experience that having cybernetics didn’t change her brain chemistry or nervous system. The same was true for a tech-priest. It was impossible to wholly eliminate the thousands of continual signals that made love or hate, compassion or derision. The teachings of the Cult Metalica were not to remove these human factors through mechanical replacement, but to adopt a philosophy of higher understanding so that one recognised and controlled them. Unfeeling machines were easy to construct. Machines with humanity, no matter how repressed, were the perfect expression of the Omnissiah’s genius.

So she knew what she saw when the tech-priest recoiled from Harkas’ Inquisitorial sigil. She had seen it in the downdecks when a tech-priest was close to a direct hit or a dangerously malfunctioning system. It was fear.

Which was understandable. Few ever knowingly crossed the path of an inquisitor in their life, and there was little affection for the other institutions of the Imperium, but that did not explain the tech-priest’s very personal reaction. The momentary response betrayed an intimate, physical threat, not a general and intellectual one.

Unthinking, she stepped closer, fuelled by curiosity. As before, her desire to call out died at the moment of its conception, buried under a sudden need to remain unnoticed. She continued to watch in mute impotency.

The magos dominus swept aside the gaggle of subordinates with a flurry of hair-fronds, looming over Harkas as two undulating manipulators extended from beneath the segmented globe. Undulating sensor-vines tasted the air around the inquisitor, cutting lines through the bluish vapour that puffed from incense vents as metal plates opened and closed like gills.

‘You are an inquisitor?’ The voice was almost song-like, each word carried on a rising cadence.

‘I am Ossissiru Harkas of the Most Holy Orders of the Emperor’s Inquisition. I have discovered a techno-heresy that imperils the Casus Belli.’

‘You are most persistent, Harkas,’ the dominus said. ‘Moderatus Prime Gevren informed me that you had been apprehended and slain. Twice. It seems that you have a gift for survival that is equal to your penchant for heresy.’

Harkas retreated several steps and swept up one of the laspistols. He darted a look at the other tech-priests forming a semi-circle behind their commander.

‘I am an inquisitor of the Emperor!’ he shouted, looking around the atrium. He lifted up the Inquisitorial sigil for all to see. His next words were directed at the magos. ‘If you kill me, my order will visit vengeance a thousandfold upon you and your companions. Better to submit to your swift execution now.’

‘You overestimate your reach, Harkas. We are not intimidated by your claims to represent the Holy Order.’

Harkas again raised his voice, lifting the sigil high and turning to address the skitarii stationed around the atrium.

‘I am an inquisitor of the Emperor, and by my absolute authority I command you to execute these hereteks!’

Ghelsa withdrew as the soldiers turned their attention on the raving man standing before their commander. Silence greeted his proclamation. A buzzing sound broke the stillness. The magos was laughing.

‘That is an interesting badge you brandish,’ said the dominus. ‘A simple thing, yet you claim it possesses the power to command armies and condemn worlds. Such is granted to only the most brilliant minds, the most determined champions of humanity. You are neither, Harkas. Your delusions have betrayed you.’

Ghelsa shook her head, scrutinising Harkas’ face. He looked as confident as he had the first time she laid eyes upon him, but the magos’ words anchored deep into Ghelsa’s own doubts.

‘It is my authority incarnate,’ said Harkas. His glance roamed the atrium once more, seeking an ally. Any ally. His eyes passed over Ghelsa and she flinched, stifling any sound, fearing he would call upon her to intervene. He did not, his gaze moving on without pause. The opposite, in fact, if she understood his next words correctly. ‘You can strike me down, but the strength of this symbol is that it is the strength of all. There are others that answer the same call. Someone else will do what I cannot, and your heresy will be punished.’

‘Nobody is listening.’ A hint of discordant frustration crept into the magos’ voice. ‘You have nothing, Harkas, but a piece of wood. You have no authority here. Your badge is worthless. A greater power holds our allegiance.’

A mechanical tendril reached out, its three claws revealed to be a portable holo-projector as a wavering image appeared before the magos. It was dark blue, slowly rotating, shaped like a cog in the same style as the symbol of the Adeptus Mechanicus. Ghelsa recognised the difference as the dominus continued speaking – eight lugs, not twelve.

‘Behold the eightfold gear of Knowledge Infinite. I possess the cardinal and the anti-cardinal, power beyond the imagining of the Machine-God.’ The magos drifted low, the segments peeling back to reveal a hideously contorted face, almost within arm’s reach of the inquisitor. The fakeskin barely moved as she continued. ‘Most importantly, these are my soldiers, Harkas. They have all been trusted with the Eight Rituals of Truth. Shout! Shout as loud as you can. Not even the corpse of the Omnissiah can hear you today.’

Chapter 11

A Spark in the Darkness

Harkas raised the pistol but a tendril snaked out, snatching it easily from his grasp. A second tentacle smashed into his face, knocking him to the floor. With a whine of suspensors, the dominus rose up, her shadow eclipsing Harkas as a circular opening appeared in her underside. From this issued a servo-skull, the muzzle of a gleaming armament protruding from its jaw. Strange light glinted from the coils along its length, reflected on the tubes, plates and cables of the magos’ artificial body.

Ghelsa clamped her mouth shut, holding in a panicked scream. It threatened to rip free all the same.

A cone of green energy burst from the weapon, bathing Harkas. Atoms danced crazily, their connective forces eradicated by the strange beam. It took just a heartbeat. One moment Ghelsa stared in horror at Harkas’ face – defiant even at the instant of his demise – the next she saw only a glowing miasma that swiftly dimmed and then vanished. Not a tatter of flesh or fragment of cloth remained.

It was as though Ossissiru Harkas had never existed.

Except for her. She knew. She remembered.

‘He may have had accomplices. Root out all treachery from every part of the god-machine,’ announced the magos, closing her metal shell before turning away.

Had Inquisitor Harkas ever existed? Ghelsa stared at the empty space where the man had stood, unsure of everything he had said. What had seemed possible suddenly became implausible. After her initial acceptance of his assertion Ghelsa had been too swept up in evasion and survival to question what he had said. It stretched credulity that the entire command crew of an Imperator Titan could be swayed to tech-heresy. Not only that, but how he had come upon the plot now appeared as an unlikely series of coincidences. None of it made much sense unless he had been lying.

One fact remained. She had been his accomplice and was as hunted now as she had been minutes earlier. Soon they would uncover the missing hyperezia and then it would take very little time to unearth documentation of their custody in the antae and pict-records of her face.

Ghelsa stepped back a few strides, avoiding the gaze of any other person. Then she turned with her head down, walking as quickly as she dared until she found herself in the comparative shelter of one of the atrium archways. She reached a hand to the wall to steady herself, her fingers finding the head of a mechanised griffin sculpted into the frieze, its wings fanned like a halo. The detail drew her in, fascinating and distracting her with minutiae. It was easier to get lost in the sensation of it beneath her fingers than to think about what had happened.

She bit her lip. Sudden pain brought clarity amid a storm of fear and confusion and desperation. All was turned against her.

Without a backwards glance, not sure where she was going, Ghelsa ran.

Movement in the sky ahead drew Exasas’ attention back to the outside. Several blurs descended from the back-lit clouds. At first they looked like meteors, but when Exasas adjusted vis perspective for scale ve saw that they were larger. Much larger.

Retro-thrusters burned into life, their light like sparks at this distance, but in reality they were pulsing jets of plasma fired to slow the descent of thousands of tonnes. Ve counted four drop pods – for such they had to be – and watched with growing anxiety as they slammed into the parched ground not far from the battle group. Dust clouds plumed from their impact, swathing any telltale livery that might have identified the occupants.

Full magnification still did not reveal much detail, but Exasas saw dusklight glinting on the edges of the drop pods as the sides of the huge structures opened outwards. Ve had briefly entertained a differential conclusion that had suggested the arrivals were reinforcements from the Legio Metalica. It evaporated the moment ve caught the glimmer of orange and black, not the red and silver of vis Legio.

Even through the poor focus of direct oculation, and without access to data from the noosphere, Exasas could see that the attacking war engines had made a serious error. Although their drop placement put them in an ideal position to attack the rear of the two Warhounds and the Warlord, they were directly in front of the Casus Belli. It seemed like a suicidal decision.

Hazy purple hemispheres engulfed the Will of Iron, the arriving Titans opening fire even as they disembarked from their drop pods. Dozens of rocket trails from a carapace launcher arced across the intervening distance, covering the Warlord in detonations. The pulsing green beams of a lasblaster accompanied the attack from a Titan to the right – a half-seen smudge that Exasas judged was a Reaver or equivalent class.

The Warhounds accelerated and turned even as the Will of Iron lumbered in an arc, trying to bring at least one of its weapons to bear. Another of its void shields overloaded with a burst of bluish sparks. Exasas was not sure, but ve thought the Warlord had two more left.

With the main battery directly above and secondary turrets all around ver, Exasas should have been engulfed by the booming of their anger. Ve did not even detect the moan of hydraulics that would have marked the great gun above ver taking aim, and the autoloader remained silent.

Visual lens tubes pressed against the armourplas, the magos watched with deepening despair as two more void shields detonated around the Warlord. The Woundwalker and Sabreclaw peeled apart and started to return fire, but divided, the Scout-class machines were outmatched by the pair of Battle Titans they faced.

A volcano cannon from an enemy Warlord – Exasas could make out its silhouette more clearly against the actinic destruction of its target’s final shield – struck the Will of Iron across the carapace, punching through the armour to erupt from the opposite flank. Flexing its power fist impotently, the Metalican Warlord swivelled a gatling blaster towards its attackers, but the other carapace weapon hung limply, its mounting damaged by the strike moments before.

Still the Casus Belli had not opened fire.

A cold, human dread gripped Exasas when ve realised that it was not going to.

It was easier than Ghelsa had expected to get back to the downdecks. In the wake of the Traitor Space Marine assault there were tributai and tech-priests coming and going through the portalways to repair the damage that had been inflicted. Squads of the new skitarii herded the workers along routes away from the atrium. It was clear that they did not want anyone close to the antae of the god-deck, though for what purpose Ghelsa could only guess.

She stood a short distance away from the starboard gallery entrance. A trio of skitarii waited by the gilded gateway. The glimmer of their radium carbines stippled the metal-lined chamber with azure light. How could anyone not know they were hereteks? The knowledge was acid in her chest, burning with its presence, as if it would corrode her from the inside if she did not share it.

She said nothing and waited until there was nobody entering or leaving the hallway. As she neared the skitarii she became hyper aware of her own body language. Were her shoulders hunched? Should she meet their stares or keep her gaze on the floor – which would look less suspicious? She tried to walk at a casual pace, but not so slowly that it looked like she was reluctant.

She held up the multi-tool like a badge of office as she entered the hallway. ‘I’m off to recharge this,’ she said, but they did not give her a second glance. Breath held, she hurried through the archway to the steps that spiralled down into the innards of the Casus Belli’s torso.

She took the steps two at a time, the occasional clash of her exo-skeleton on the rail throwing up sparks in the increasing gloom. On a twinned set of steps running alongside, a tech-priest led a party of duluz up into the akropoliz.

‘Ghelsa!’

Instinct warred between freezing and running. Paralysis won. Barely turning her head, she sought the source of her name. Notasa’s delicate features were visible in the dim light.

‘Where in all the realm of the Omnissiah have you been hiding?’ he demanded. His expression swiftly changed from relief to anger. ‘I thought you were dead!’

Ghelsa dared not speak. She could not trust herself to speak – anything she said might get her killed – and worse, condemn Notasa too. She simply stood in shocked stillness, staring at the other tributai.

‘I’m the one that’s meant to be upset,’ Notasa continued. ‘Giving me the silent treatment isn’t fair.’

‘It was… important,’ Ghelsa managed, trying not to cry. She wanted to leap over the divide and hug Notasa, to feel something from the life that had fallen away beneath her in just a few short hours. But the taint was on her. She would be hunted and killed, and anyone with her would suffer as well. Harkas’ acquaintance was like an infection, and now she was the carrier.

‘It’s always something else that’s important,’ said Notasa. He looked up, frowning. ‘You’ve been in the akropoliz? Why have you been up there already? There’s been fighting! By the Omnissiah, Ghelsa vin Jaint, what have you been doing?’

‘Stay safe,’ Ghelsa blurted, and then dashed down the steps, the multi-tool and her callipers clanging against the metal of the central column.

‘I love you!’ Notasa called down after her.

‘I love you too,’ whispered Ghelsa.

She reached the bottom of the stairwell and stumbled into the ruddy ambience of the downdecks, heading for the dead space between the plasma exchanges – the most isolated place she could think of.

A temporary star lit the desolate basin as the Will of Iron’s plasma reactor detonated. The flash lasted only an instant but was seared across Exasas’ archive circuitry. A Warlord Titan had been destroyed while the Casus Belli had simply looked on. Ve knew little enough about MIU transmission, but ve had to imagine that the spirit of the Imperator was howling for vengeance now, chained by the treachery of the princeps senioris and moderati.

Others among the tech-priests and lower ranks would know what had happened. Not all of them could be part of the conspiracy. Could they?

It was a near-zero probability that of all the officer-elevated members of the Cult Metalica Exasas was the only one not party to the plotting. If that were the case it would have been far easier to have removed ver from duty before the Imperator left its drop barge.

Ve desperately wanted to know what was happening, and in particular to identify the Legio of the Titans that had cooperated in the ambush. That data would go a long way to revealing the extent of the traitorous influence within and beyond the Legio.

Exasas turned from the window as the two Warhounds started to flee, void shields sparking under the gunfire of pursuing war engines. An idea lent further urgency to vis thought process – not that ve felt a lack of haste. The rest of the battle group was yet to emerge from the storm, and they would surely fall foul of the ambush. If ve could access the noosphere in some way it might be possible to make some form of emergency signal to the others. The likelihood of such a broadcast penetrating the storm layer was marginal, but it was better than no plan at all.

Was this the sort of situation where assumptions were better than presumptions? Was there some leap of intuition Exasas was incapable of making that would lead to a solution to the current problem?

It was a waste of processing potential to ponder unknowns, so Exasas focused all available algorithms and antarithms on devising a means to circumnavigate the noospheric block.

Ve presumed that Olvatia was not foolish enough to have placed the jamming device in a position where Exasas could access it.

Exasas-secondary: <Your presumption is ruling out non-zero possibilities.>

Exasas-primary [inquiry]: <How are you here?>

Exasas-secondary: <You did not completely deactivate my protocols. When you partitioned me into Olvatia’s systems you reawakened me. I have been running containment simulations on your background systems.>

Exasas-primary: <I see.> [inquiry] <How is my presumption flawed?>

Exasas-secondary: <It masks an assumption. To whit, that Olvatia is infallible.>

Exasas-primary: <The detail with which the coup has been planned and executed demonstrates a high level of coordination and forethought. It is unlikely that Olvatia and her allies have made a basic error.>

Exasas-secondary: <Unlikely but not impossible. Given that we have nothing else to do, exploring near-zero possibilities is as worthwhile as any other course of action at present.>

Exasas-primary [inquiry]: <So I am not to presume the traitors placed the noospheric interceptor out of reach?>

Exasas-secondary: <Exactly. I also have another suggestion.> [imperative] <You need to detach and awaken Exasas-tactical.>

Exasas-primary [inquiry]: <Why would that help? I am already diverting processing pathways to your existence – further subdivisions seem counterproductive. I also do not have my warskin. Exasas-tactical lacks the strategic understanding of this situation.>

Exasas-secondary: <We are not in a strategic encounter. We have no noospheric reference. Although no foe is directly present, our predicament is the result of direct enemy action.> [theory] <Escape is, above all other things, a tactical matter.>

Exasas-primary: <That is remarkable.> [inquiry] <How did you come by such an interpretation?>

Exasas-secondary: <You based me upon your strongest antarithms. I have been devising methods by which I would contain you. Denying you access to the noosphere is the first essential stage. However, had I been your enemy I would have also ensured you posed no further threat by negating Exasas-tactical. Denied the data needed to function strategically and the base-level thinking of your command-self, I calculated a ninety-nine per cent probability that you would be unable to contact the outside.> [theory] <Olvatia making the mistake of not disabling Exasas-tactical implies that she is fallible, hence the nature of my first intercession.>

Delight at vis own cleverness briefly eclipsed Exasas’ concern, but it returned swiftly. Ve descended and started a thorough scanner sweep of the magazine shell, seeking any sign of a noospheric device. At the same time, ve retasked several routines in vis primary processors to approximate the circuitry of the warskin and started to assemble the battle-persona.

Exasas-tactical: <I have appraised myself of our current predicament, and while it is perhaps a small inefficiency, I must ask how you did not see this possible conclusion.>

Exasas-primary: <You are correct, it is an inefficiency. However, I will indulge you while we seek the location of the noospheric jammer. I posit that in retrospect this outcome seems inevitable, but that it was impossible to predict given the data available to me previously.>

Exasas-secondary: <Perhaps it required an assumption to make the leap of logic.>

Exasas-tactical: <Your focus is on yourself, while I run my core processes on the basis of what the enemy is trying to do to defeat me. Your basic error was in not recognising that there was an enemy at all.>

The nerve-crackling sensation of interference was stronger at the base of the magazine, close to the inner vault. The store itself could only be accessed from below or from the gun tower above; the wall within the magazine was solid ferrocrete laced with reinforcing bars.

Exasas-primary: <Olvatia did not make a mistake. We cannot reach the device.>

Exasas-secondary: <That does not fundamentally alter the theory that she may have made a mistake. We simply have to keep examining possible errors.>

Ghelsa sat with her legs pulled up to her chest, her head resting against the downpipe of the plasma exchange behind her. Sweat rolled across her skin, the heat and humidity the main reason this area was shunned when possible. She liked the warmth that came from the broad conduit, and every few seconds it shuddered slightly. It felt like a pulse, the heartbeat of the Casus Belli, strong and steady. It matched the rhythm of the torso’s sway as the Imperator strode relentlessly onwards. Implacable and eternal.

This was her home.

It had been tainted. Everywhere but this shadowed spot felt hostile, an alien place that wanted her dead. It was just a matter of time before they found her, beat her, carved the signs of the heretek into her and stripped out her augmentations.

Ghelsa lifted a hand to the symbol in her brow, a rare sign of blessing by the Cult Metalica. It had been the reward gifted to her for the year of pain she had endured and the year more of rehabilitation following the insertion of the exo-skeleton. She had dedicated her body to the Machine-God and endured the test that had followed.

All of that meant nothing. It was scrap metal that would be reclaimed from her still-living body before they steam-blasted her into oblivion.

For what? A madman posing as an inquisitor? It was ridiculous how easily she had allowed herself to be played by his lies. Harkas had used her as a shield. She had vouched for him with the duct-fighters! Having been foiled once in his corruption of the Casus Belli, he had found a willing pawn in Ghelsa.

She should have just let the hyperezia beat him to death.

And what was his proof? Nothing. Everything he had insisted depended upon a stupid piece of wood. He had risked everything for that flimsy disguise. As if an inquisitor would just turn up at the Casus Belli with nothing more powerful than a decorated sigil. Why had he not brought skitarii or perhaps even Space Marines? With the entire resources of the Imperium at his disposal he had thought a small wooden ‘I’ could overthrow the command cadre of an Imperator Titan.

And now that Ghelsa thought of it some more, that sounded even more outrageous than the tech-priests attempting to deliver the Casus Belli to the traitors.

A sudden thudding of heavier tread drew her eye to the deck above her. She heard voices raised in complaint and snarled words in return. There was more argument, cut short by a shriek of pain.

Ghelsa was on her feet in an instant, her heart racing. It had to be the hyperezia looking for her.

Another pained shout shot through her nerves, followed by something hitting the decking. The exchangers were lit by the glow of status lights in a panel not far away, and in the amber gleam Ghelsa saw something drip through the crack between two decking plates.

She moved forward and held out a hand. Another droplet splashed onto it. It looked ruddy, but the light cast a reddish hue on everything. Lifting her hand to her mouth, she licked the drop.

Blood.

The dripping became a trickle, and horror stole through her with the realisation that it was not going to stop. This was not a broken nose or cut lip – it was the last life fluid spilling from someone in the plasma chamber above.

Ghelsa stumbled away, narrowly avoiding the tubing that cut across her path. Fear and anger warred inside her. They were close, so close to finding her. The thought of her slow death was terrifying, almost as dread-inspiring as the shame of her excommunication. She would be swiftly forgotten, but for a while at least among the duluz she would be known as a heretek – her death would be the example to remind the others of the price of disloyalty.

And what if they thought she had corrupted others? Would they come for Notasa?

The anger was stronger, fuelled by that thought. They had just killed someone out of hand, perhaps for trying to resist their hunt, or perhaps for speaking out in defence of Ghelsa.

She could not have that blood on her conscience.

Ghelsa reached the ladder up into the plasma chamber and stopped, hearing other raised voices. There were more footfalls, booted and bare, and she looked up through the opening. She caught a glimpse of white cloth. Not the robe of a tech-priest but the coat of a skitarii. Changing the angle brought the muzzle of an arc rifle into view.

That explained the increasing dissent. The downdecks were the domain of the tributai and the epilekhtoz, off limits to the skitarii.

She heard the words of a skitarii alpha cut through the babble of shouting, her voice empowered by a volume modulator.

‘No shooting in here. Do not open fire!’

The soldier at the top of the ladder took a step away, revealing more of the blue-bathed plasma chamber. Something brighter sparked white into the gleam, accompanied by a hissing and then a high-pitched wail. The fury of the duluz voices intensified rather than abated at this attempt to cow them. Metal-edged skitarii demands rose in volume in response.

A terrible doubt gnawed at Ghelsa.

What if Harkas had been telling the truth?

While she did not doubt that hereteks had conviction for their twisted causes, Harkas’ utterly indefatigable nature suggested a confidence far greater than anything she had encountered before. His single-mindedness in recovering his sigil and the utter contempt he had shown to the new magos spoke of an unshakeable faith in himself. He had feared failure more than death.

And if he was to be believed, that failure was nothing less than the corruption of the Casus Belli. The same magos that had vaporised Harkas had sent skitarii into the downdecks. Even Ghelsa, who had never lauded herself as the quickest of thinkers, could see there could only be one reason for that – to subjugate the duluz.

Her fingers curled around the rungs and she started to climb. Her thoughts burned with something Harkas had said at their first meeting.

‘And if what I say is true, and the Casus Belli is turned against the Imperium, you would be purged along with the others of the crew not party to the plot.’

The skitarii were not just enforcers – they were executioner squads awaiting the command. Anyone that did not openly swear loyalty to the new regime would be killed.

The soldier at the top of the ladder looked at her as she clambered up. Its face was hidden behind a lensed mask, jutting ridges of cybernetics pushing the white coat into odd shapes around the shoulders.

The skitarii levelled its arc rifle at Ghelsa.

‘Wait there,’ the soldier ordered.

Ghelsa hauled herself into the plasma chamber and stood on the rim of the ladder hole.

Located at the heart of the Casus Belli’s torso, the chamber was really a series of interconnecting rooms and walkways around the immense plasma reactor at its centre. The huge sheathed star that powered the Imperator was contained within spherical layers of ferrocrete, plasteel and magneto-shields, the outside studded with large hexagonal bolts. Around it were several walkways, stairs and tertiary levels broken by banks of monitoring gauges, control stations and access ladders. Power feeds each thicker than Ghelsa’s waist spread like roots from the base of the globe to the motive engines, bastions and void shield generators, while overhead splayed the branching conduits running up to the weaponry and command stations far above.

Several dozen tech-priests and duluz were drawn up in angry clusters, surrounded by two squads of armed skitarii. Three tributai lay on the deck – one with the side of her head crushed, the others perhaps also dead or only unconscious, it was impossible to tell.

‘Halt,’ the skitarii said again, taking a step closer, around the ladder hole.

The downdeckers eyed the soldiers sullenly, growling and shouting their dissatisfaction. A little ahead of the others, a golden-masked alpha confronted the largest group, where two tech-priests blurted endless binaric at the interlopers, to no avail.

Nobody else was paying any attention to Ghelsa.

She moved towards the skitarii, swinging the multi-tool towards the soldier’s head. It connected with a metallic clang, snapping the skitarii’s head sideways, neck broken. As the soldier crumpled, Ghelsa guided the body into the hole with a shove.

As one, the remaining skitarii turned towards her, detecting the death of their companion over their squad-link.

‘No shooting!’ the alpha commanded again. Five of the closest soldiers started towards Ghelsa, their rifles couched, pulling shock mauls and long blades from their belts.

‘We are betrayed!’ Ghelsa shouted, lifting up the multi-tool as though it were the war banner of the Legio. ‘Defend yourselves!’

Exasas-tactical: <Placement is crucial.> [theory] <The range of the jamming signal must be quite limited so that it does not interfere with the running of the Casus Belli beyond this chamber.>

Exasas-secondary [theory]: <The signal must be directional. If the zone of influence were equal in all directions it would be spherical, which would suggest the best placement in the centre of the magazine, not the bottom.>

Exasas-primary [datalog]: <You are correct. Counter-noospheric waves increase in intensity the closer we come to the device.>

Exasas-tactical: <Reviewing your datalog, I find that Olvatia descended to meet you when you entered.> [inquiry] <Is it possible she did not wish for you to detect the weakening of the noospheric interference as you ascended?>

Exasas-primary: <That would be conjecture. It is impossible to determine her motives for a specific act.>

Exasas-secondary [conjecture]: <Olvatia picked this location because it is a chamber of sufficient size within the akropoliz to encompass the minimum settings of her device.>

Exasas-primary [interrogatory]: <I was not aware of a conjecture mode. Conjecture requires assumption.>

Exasas-secondary: <I created conjecture mode while I ran my simulations.> [imperative] <Address the basis of the theory.>

Exasas-tactical: <I have analysed the layout of the akropoliz within the parameters you suggest, and there is no other chamber of sufficient size to contain the interference field without impacting access to other systems.>

Exasas started up the rampway at speed, impelled by a sudden conclusion.

Exasas-primary: <Olvatia requires the main battery to be operational. The main battery is overseen by the ballisticus called Mithras-4. Mithras-4 requires a noospheric uplink to interact with the moderatus prime.>

As ve ascended, the effect of the jamming signal lessened. It still prevented any kind of link, but the magos sensed the noosphere’s presence beyond the interference, much like one can detect a light coming on through eyelids. Ve accelerated, all vis jointed legs churning to propel the excited tech-priest upwards.

Exasas-primary: <The ballisticus’ position is close to the autoloader near the base of the gun tower. It is likely that Olvatia did not want the jamming field to extend above the ceiling of the magazine. Depending upon the calibration parameters, it is possible that the signal is sufficiently depleted before it reaches the barrier of the ceiling.>

Reaching the highest level, Exasas moved around the walkway to the opposite side from the location of the jamming device far below. Ve reared up as far as possible, extending vis segmented body with a hiss of pneumatics.

The interference had almost gone, a quiet hum compared to the earlier crackle. But it was not entirely dissipated. The noosphere remained an unreachable aura just beyond vis transmitters.

Exasas-tactical [request]: <Allow me access to our motivation circuits.>

Exasas complied with the sub-persona and climbed to the sill of the closest window. From here ve stretched up again, extending every body part and limb in an effort to get as close as possible to the ceiling. Straining mechadendrites brushed the painted ferrocrete.

In that moment there was a flash of noospheric connection.

Ghelsa’s defiance was all the other tributai needed, the finger on the trigger of their building anger. First one mob and then the others surged towards the skitarii, some with tools as improvised weapons, most with bare hands outstretched.

The skitarii responded with crackling clubs and gleam-edged blades, battering and cutting at the first to fall upon them. Faced with two soldiers dashing across the lowest level directly at her, Ghelsa had no time to spare for those who fell.

Lacking any better ideas, she threw herself into a counter-charge, whirling the multi-tool in front of her. Its sweep knocked the maul from the hand of the first and she barrelled into the soldier without stopping, bearing both of them to the floor. She thrust exo-skeletally boosted fingers into the soldier’s facemask, crushing the metal and shattering the plastek lenses, burrowing fingers through bone into the brain within.

She expected to feel the thrust of a blade in her back or the impact of a maul, but nothing happened. Dragging her blood-coated fingers from the ruin of the skitarii’s face, she turned to see the other being hoisted up by the clawed mechadendrites of one of the plasma reactor overseers.

Red incense spumed from the tech-priest as a metallic roar reverberated through the chamber.

‘Spare none! Eliminate the hereteks!’

Exasas-secondary [imperative]: <Get us closer! We almost had a positive link.>

Exasas-tactical [rebuke]: <This form was not designed or constructed for its current employment. If I make an error we shall fall.>

Exasas had clambered fully into the window enclosure and gripped the top with a pair of manipulators while resting the very tip of vis metallic tail on the sill. Legs splayed, ve lay against the glass and wall, every articulate part stretched to maximum.

Ve made minute adjustments to vis stance, trying to find the elusive connectivity they had encountered minutes before and then lost. Like a shadow on a wall, the noospheric presence of Mithras-4 projected into their senses but was not tangible. If Exasas could make a connection to the other tech-priest’s noospheric circuitry, ve could communicate again.

Exasas-tactical [negative/imperative]: <You cannot reveal us to any of the other tech-priests. Without positive data on who is privy to the conspiracy we must assume that all others are the enemy.>

Exasas-primary: <Then our efforts are wasted.> [inquiry] <If not to communicate our predicament to the outside and seek assistance, to what purpose do we labour?>

Exasas-tactical: <Achievement of the connection is the primary goal. We can devise the next phase when it has been completed.>

Exasas-secondary: <I concur with Exasas-primary. Our thinking cannot become too short-term lest we follow a course of action that is ultimately without merit. Time is limited.>

Exasas-tactical [theory]: <You should devise a strategy while I focus on the immediate mission.>

Exasas-secondary [imperative]: <Do not attempt contact. Even if you think you have identified an ally, any precipitous attempt to enforce our freedom will endanger them. We must remember that the goal is not our escape – that is one possible means to the end. Our only purpose is to thwart the coup and restore control of the Imperator to those loyal to the battle group.>

Exasas-primary: <I am accumulating a list of injunctions but as yet have not rendered a positive outcome once connection is established.> [inquiry] <What are we trying to achieve?>

Exasas-tactical: <Establish a connection with the tech-priest and I will make it secure. Once we have noospheric data you can better establish the parameters of the next stage.>

Exasas-secondary: <I concur.>

Exasas-primary: <I was not aware that we had adopted democratic principles for this decision-making process.>

Exasas-tactical [rebuke]

Exasas-secondary [rebuke]

Chapter 12

Ultimate Sacrifice

The alpha’s injunction against weapons fire lasted only a few more seconds before the crack of shots rang out. Lightning bolts leapt from arc rifles, searing through the nervous systems of the charging duluz. Bullets tore at coveralls and robes, pitching Ghelsa’s companions twitching to the deck.

The din rushed at her like a living thing, drowning out her thoughts, each flash of muzzle flare or pulse of electricity sending a shock into her. Through a welter of conflicting responses Ghelsa forced herself to act. She pulled a stub carbine from the dead grip of the skitarii whose face she had crushed and turned it on a trio of soldiers firing at the tributai from a higher level.

Even with just a single hand, her reinforced grip made light work of the recoil. Her aim was poor but she kept the trigger pulled and walked the trail of bullet impacts across the coated figures above. White fabric turned red as the rounds found their targets, punching through the armour below the skitarii’s coats.

The repeated clicking of her weapon signalled an empty magazine. She had no idea how to reload and instead used her augmented strength to throw the carbine into the face of another soldier.

Others had wrestled weapons away from the skitarii, and erratic radium beams lit the spreading melee while artificial lightning chained across those who had been sent to occupy the downdecks.

A sudden fountain of red sparks cascaded from an energy conduit, showering onto the combatants below. A second later, a stub round pierced a coolant tube, the venting gas freezing an unfortunate tributai standing next to it.

The tech-priests called for their duluz to cease firing, but the enraged workers did not listen. Bullied and threatened, their fear had turned to rage against those who had betrayed them, exacting a bloody price for the abandonment of the unwritten covenant that had existed between skitarii and duluz. The one protected the other, and in return the tributai and epilekhtoz maintained the god-machine on which they all depended.

Ghelsa’s fury was born of a survival instinct. She had felt the greater machination at work, seen first-hand the carnage of the Traitor Space Marine assault that surely had to be connected to the plot. If they did not stop the conspiracy the Casus Belli would be irrevocably tainted, defiled by those who had been oathbound to serve it.

The closest skitarii were embroiled in a desperate hand-to-hand fight, cleaving at their tributai attackers with blades that left snaking trails of energy. Ghelsa threw herself into the tech-guard and brought the multi-tool down onto a hooded skull, gritting her teeth against the sensation of splitting bone. The soldier folded sideways with a strange, artificial squeal.

Ghelsa wrenched the multi-tool from the remnants of her dead foe, the metal slick with thick greenish liquid. More of the same pumped through the weave of the hood and flowed towards her bare feet, forcing her to step back.

Something continued to move within the folds of fabric. It looked more like a nest of waking serpents than anything human. Ghelsa bit back her disgust and dragged back the hood to reveal a mass of writhing tentacles where the skitarii’s brain should have been.

Revulsion threatened to empty Ghelsa’s stomach, had there been anything to expunge. This was no cybernetic augmentation – something inhuman had been inserted into the tech-guard’s body.

The other fighters overwhelmed the remaining pair of skitarii, battering at armoured bodies with their fists and torque bars, stabbing into masked faces with the tips of screwdrivers.

From above, more missed shots slashed trails through hanging wires, while control consoles exploded with sparks from other impacts. Ill-judged arc blasts seared along monitoring circuits with emerald flashes. Several misplaced bursts cut down slaved servitors attached to the reactor monitoring panels.

Faces swam in and out of focus, but Ghelsa could not see Notasa among them. Pushing her way through the mob, she recognised Adrina – barely, for the overseer’s features were contorted in an unfamiliar rage. Blood spattered his face as he beat the claw-head of a long-handed mattokhai’s hammer repeatedly into the chest of a fallen skitarii.

She pushed through the other tributai and shouted for Adrina. He looked up, his eyes wide and wild. He swayed like a drunkard, his brow knotted in confusion.

‘Notasa? Have you seen Notasa?’ Ghelsa demanded, stepping closer to the overseer. ‘He went up into the akropoliz.’

A semblance of focus returned to Adrina’s eyes. He looked at Ghelsa, still frowning, and then to the bloodied hammer in his hands. Blinking red droplets from his eyelashes, he let the mattock drop from blood-slicked fingers and swallowed hard.

‘Ghelsa? Where did you come from?’

‘Have you seen Notasa?’

He shook his head and then looked around as though he might see him present. His gaze fell upon the tributai whose skull had been crushed.

‘They killed Rhiassa…’ He looked so lost, utterly unlike the Adrina she had known for many years. Ghelsa laid a hand on his shoulder and he turned his attention back to her, regaining a semblance of his former confidence. ‘There were others, I think, that started it. The skitarii came for the starboard shift. Orasni’s team. A fight broke out in the secondary stairwell.’

Ghelsa noticed that the chamber had quietened, the din of violent struggle replaced with the growl of the reactor purging and the murmur of the surviving duluz.

The bodies of skitarii and duluz littered the stairs and decks, finally equal in death. Groups of survivors picked through the fallen soldiers, some driving lifting spikes into their chests to finish them off, others relieving them of weapons and ammunition.

The tech-priest that had roused the fight – Ghelsa recognised the brass-effect faceplate beneath the hood as belonging to Premidius Sushus-Gan – pushed through the throng, parting them with questing prods of her mechadendrites.

‘You!’ Sushus-Gan barked, pointing a metal claw at Ghelsa. She stiffened and adjusted her grip on the multi-tool.

Exasas powered down as much motive energy as ve dared, and also reduced the life-support mechanisms for vis few organic components to a slower cycle. Cell degradation would increase, but it was a sensible sacrifice in exchange for the ability to boost the range of vis noospheric interface.

Like a person feeling their way forward through a thick fog, trying to find another without them being aware of it, Exasas projected vis noospheric field through the ceiling of the magazine, searching for Mithras-4. If the other tech-priest was not at his post, even by a short distance, the entire enterprise would fail.

The static became a haze through which Exasas could make out the vague electromagnetic signatures of the systems above. The blocky machine of the autoloader dominated everything, but next to it was a smaller but more intense locus of data. Snaking an info-tendril towards the apparition, Exasas identified the source wave of Mithras-4’s noospheric hub. If ve made connection with it at the wrong frequency it would instantly alert the ballisticus to Exasas’ presence.

Exasas-tactical primed verself to act, reconfiguring several data-broadcast processes while Exasas-primary concentrated on matching their target’s data waveform. Confident that ve had a confluent signal, Exasas eased even more power into vis noospheric projector, like a fallen climber straining every muscle to lay a fingertip upon a dangling rope.

With a last surge that blanked out several data archives, Exasas thrust vis projection into Mithras-4’s waveform. At the instant of contact Exasas-tactical asserted full functional control, sidelining the primary persona.

Exasas-primary was a partial spectator, partial actor as the two noospheric signals overlapped. Exasas-tactical pounced like a predatory feline, unlocking battle-algorithms usually reserved for manoeuvring bodies of troops and prioritising enemy targets.

The magos’ personal wavelength slipped into the circuitry of the ballisticus without a tremor, spreading from the noospheric nodes into Mithras-4’s secondary communication and motor centres, while a third assault diverted to the failsafe module each of the Casus Belli’s tech-priests possessed to alert the Imperator to their demise.

Defensive systems swarmed like wasps defending their nest, but Exasas-tactical was battle-shielded against enemy interrogation and pulsed through them without concern. Descending persona shields were broken or wedged open by the spreading data-surge, Exasas-tactical’s abilities growing in potency with each system that was taken over, while Mithras-4’s were diminished. With an infoblade cutting off every connection ve encountered, Exasas multiplied out into the other tech-priest’s datawork.

A core-protocol – one might think of it as a death throe – tried to eject Mithras-4’s archive coil contents into the noosphere, both as a preservation technique and an alarm. Exasas-tactical had been expecting the response and latched onto the broadcast at the moment of its emission, using the millisecond-long window of transmission to swallow the data-blurt and concurrently burrow into the ballisticus’ cortex via the archival vessels.

Such was the speed of the attack that tertiary defences had not even activated. There was no sensory shut down, no datalog erasure, not even an organic reaction to betray Exasas’ intrusion.

A little under a second after first contact, Exasas was in every part of Mithras-4’s digital systems, and the other tech-priest had not an inkling of what had occurred.

Lurking inside Mithras-4’s persona strands, Exasas spent several seconds analysing the ballisticus’ thought routines. Much of it was standard, although he still possessed the organic matter of the brain, something Exasas had not experienced for over a century. It took several more seconds of adjustment to calibrate vis processes in line with the firing of neurons.

Thus ensconced, Exasas started to decode the dataflow, parsing away sensory, noospheric and datalog strands for separate analysis. Ve focused vis attention on the ten minutes since ve had departed from the control module.

The first thing that became clear was the identity of the Titans that had landed. Their orange-and-black livery flowed in crystal-sharp focus from the Casus Belli’s sensors.

The Legio Fureans, colloquially known as the Tiger Eyes.

A rapid exchange of consternation between Exasas’ personas threatened to destabilise their link with Mithras-4, and it took an effort to regain equilibrium. The presence of the Fureans changed everything.

Exasas-primary: <The Tiger Eyes have been recognised as renegade since the Great Schism. These are not sympathisers from a fellow Legion but adherents to the rites of the Dark Mechanicus.>

Exasas-secondary: <We have laboured under the misapprehension that the conflict was between two factions loyal to the Machine-God.> [reinterpretation] <Olvatia spoke not of a sect within the Cult Metalica but of the tenets of the Dark Mechanicus. She and the others have become corrupted.>

As ve analysed the import of this, Exasas noted that one of the Warhounds had so far escaped destruction, drawing two of the Furean Reavers deeper into the mountains. That left a pair of Warlords standing ready to attack whichever Titans of the Legio Metalica emerged next from the storm.

Exasas-secondary: <What we interpreted as opportunism following the erratic behaviour of the Az Khalak defenders was in fact a meticulously planned and executed plot to destroy the battle group.>

Exasas-primary: <Analysis has shown that they were presented with more effective means to destroy the Casus Belli prior to this point.>

Exasas-tactical [imperative]: <Your analysis is inverted because you have proceeded from the basis of destruction.>

Exasas-primary [inquiry]

Exasas-tactical [theory]: <The conspirators plan to deliver the Casus Belli into the service of the Eightwards Conduit.>

Exasas-secondary [theory]: <The traitors do not wish to destroy the Casus Belli – they wish to subvert it to their cause. Every act carried out has been arranged in such a manner as to lead towards the isolation of the Imperator for that end. Had they merely turned their guns upon the battle group they would have been outmatched. By this means they have been able to alter the balance of power within the battle group so that the Imperator is the deciding factor, not the minority.>

Exasas-tactical: <Unless the rest of the battle group arrive individually – a small probability – two Warlord Titans are insufficient to match them for kill potential.> [theory] <The Casus Belli must become directly involved in the destruction of the Legio battle group.> [imperative] <We must prevent that.>

Exasas-secondary: <I have just recalled a routine I archived earlier. I suggested that the attack on the akropoliz was doomed to failure but perhaps aimed at drawing troops away from the defence of the bastions from another force on the ground. No such second wave transpired, and so I idled the simulation. I was right, however, but not in determining the final purpose.> [theory] <The fighting was indeed intended to empty the bastions, not for a direct enemy assault but to predicate the necessity of bringing aboard Olvatia and her augmentatii.>

Exasas-primary: <If one follows the logic you have established, then our skitarii were deemed a threat to the successful completion of their treachery. The strength of the battle group is uncertain. We are still best placed to disrupt their plans.>

Exasas-tactical: <Positioning is important but of no value if one does not have the troops to exploit it. I have analysed the simulations you ran when confronted by Olvatia’s ultimatum. While improvements could be made, the conclusion was correct. The skitarii under your command are insufficient to defeat the League forces.>

Exasas-secondary [conjecture]: <The fate of everyone aboard the Casus Belli is at stake. Is it possible to reach outside the established military structure to create a new auxilia?>

Exasas lacked the equations to fully process that possibility, but as ve attempted preliminary simulations ve trawled through the datalogs scraped from Mithras-4’s archive. Ve filtered relevant information through to the tactical persona, hoping that some fresh initiative not present in the earlier simulations might be found.

Exasas-tactical: <A cluster of coded noospheric signals around the plasma chamber. I do not recognise the League ciphers, but several data-blurts pertain to the tech-priests of the Casus Belli. Given their sudden intensity, it is a high probability that some crisis is occurring with the plasma reactor.> [imperative] <Focus on the disruption there.>

An intrusive data-spike interrupted their deliberations. Exasas-tactical fended off an inquiring data-spear from the noosphere, looping back Mithras-4’s own secularity protocols to assure the system that nothing had changed. It was a finite response – eventually the noospheric link would detect the anomaly – but Exasas estimated that they had at least thirty standard minutes before their intrusion would be detected.

Previously, thirty minutes would have sounded like an age to Exasas. Now it sounded like a worryingly short time to save the Casus Belli.

‘What is your name, tributai?’

‘Ghelsa vin Jaint, your holiness,’ she replied with an automatic bow of her head.

‘You have done a great service to the Machine-God this day, Ghelsa vin Jaint.’ The premidius turned to face the crowd that had gathered about them. ‘Hereteks are attempting to take possession of the Casus Belli. That cannot be allowed. The augmentatii of the renegades will know what has happened here, and even now are preparing their response. We do not have much time. The Imperator must never fall into the hands of the traitors. To prevent this we will initiate a fatal error in the reactor systems.’

The tech-priest turned towards one of the upper banks and snarled a stream of binaric at the servitors stationed there. The near-lifeless humachines roused into ponderous action, burbling command codes as their jolting fingers worked at the reactor controls.

Ghelsa looked at the other downdeckers and saw their confusion and hesitation.

‘We don’t have a choice,’ she said. She fixed a stare on Adrina. ‘I…’

What was she to say? That she had met an inquisitor of the Imperium, helped him clamber up the Imperator to the akropoliz, survived an invasion of Traitor Space Marines, made a pact with the Armageddon tunnel fighters, been escorted by a kastelan into the holy decks, survived near execution by the hyperezia and witnessed that same inquisitor slain by a renegade magos whose troops were now attempting to take over the downdecks?

‘Do you trust me?’ she asked instead.

Adrina had no time to answer. A warning clamour screamed into life and alert lights bathed the battle with a scarlet hue. The reactor overload had begun.

The raucous howl of the reactor alarms drowned out all other noise and threatened to shake the thoughts right out of Ghelsa’s head. The other downdeckers covered their ears, stumbling towards the exits, but she forged towards Sushus-Gan. The tech-priest was surveying the scene without any indication that it understood the pain the noise inflicted.

‘Shut it off!’ screeched Ghelsa, the effort of raising her voice sending jarring spasms through her jaw. ‘It’s deafening us!’

The tech-priest looked at her with multi-lensed eyes, and a second later the wailing ceased. Ghelsa let out a gasp, almost choking on the comparative silence.

Touch the tech-priest.

Ghelsa thought she had heard a voice, but other than Sushus-Gan, there was nobody near her. She started to turn away, but the voice came again, halting her.

Make physical contact with the tech-priest.

Ghelsa felt a throbbing in her brow – not quite pain, more like a steady pressure that seeped between her eyes.

Stay there.

Not sure what else to do, Ghelsa remained where she was, looking around the plasma chamber for some indication of who was speaking. Near-mindless servitors laboured at their controls, and the downdeckers gathered around Adrina and the other surviving overseer were discussing what they were going to do.

The tech-priest suddenly froze, mechadendrites in mid-undulation, then the body half-turned as the premidius took a step away from Ghelsa. The tech-priest twisted back, a clawed hand reaching up towards Ghelsa’s face. She stepped back but Sushus-Gan lunged after her, snaring her coverall. A glinting data-spike flashed upwards and Ghelsa flinched, sure that its tip would pierce her throat.

The slender spike lightly touched her godplate. The contact was like being struck by a bolt of lightning.

Nerves buzzing, Ghelsa stood transfixed, as if the data-spike had been driven into her brain. Her exo-skeleton twitched, juddering her body and limbs. Her fingers spasmed and the multi-tool dropped loudly to the deck. Immaterial fingers quested into her thoughts, numbing with their touch, paralysing any effort to speak or move.

The fingers became wire-like probes that spread into her consciousness. There was no pain, but the fear of intrusion was very real. Tears rolled down Ghelsa’s cheeks as she felt the probes’ invasive presence pushing deeper and deeper.

They found her memories and in moments emptied her of everything she had been. She experienced her life in swift reverse, from the battle against the skitarii, through her encounter with Harkas and onwards, back into her Cult Metalica initiation and all the way through to her childhood and birth.

Everything she had experienced, every moment that had led up to her being the person she was there and then, was pillaged, sifted and then thrust back into her memory.

Teeth gritted, she waited for the exploratory influence to depart. She stared at the tech-priest thrusting the data-spike against her forehead, but Sushus-Gan was as immobile as Ghelsa.

The tributai expected disconnection, but instead felt a build-up of pressure as an influx of information flowed from the other presence.

As she had relived her own existence, now she lived another. The earliest memories were vague, time spent among the temples of Metalica with others of the upper hierarchy. Accepted into the ranks of the tech-priesthood, she started to study the paths of wisdom, replacing more and more of her body with cybernetic components until eventually her brain itself was removed, redundant alongside the miracle of the Machine-God’s artifice that she had become. Battles flashed past, an unending war fought in numbers and equations she could not possibly understand, and then she stood before the Casus Belli, filled with an all-too-human pride in her achievement.

More war, now as a tech-priest aboard the Imperator. Skitarii came and went, each a fleeting life spent in the service of the Omnissiah. She endured. Until now.

All that she had witnessed and been told now made sense. She learned of the moderatus prime and Magos Olvatia and the Dark Mechanicus that worshipped the warp as a living god. And the blaze of recollection finished with her imprisonment in the magazine structure within the akropoliz of the Casus Belli.

The voice returned, but now with a sharp clarity as though the speaker were literally at her ear. Yet it was not sound, or even speech, but data being processed, swifter than any words.

Exasas-tactical [apology]: <Apologies for the manner of my introduction. Data-exchange was the swiftest means to appraise myself of your history and to inform you of mine.>

Ghelsa-tributai [inquiry]: <How…? Who are you? What is happening?>

Exasas-tactical: <You know who I am. I have implanted an adequate portion of my thought-stream within your biological archive.>

For a moment Ghelsa wasn’t sure what a biological archive was, but then realised the other person meant her memories. That simple realisation unfolded the entirety of the data-packet that Magos Dominus Militaris Xaiozanus Skitara Xilliarkis Exasas had inserted into her brain. She did not experience it as she had during the inload, but remembered it as though she had perhaps learned its details from a tutor.

Ghelsa-tributai: <You are – were – the magos dominus. You have been ousted by the other one, Olvatia, and are trapped inside the akropoliz. You have temporarily taken over Sushus-Gan’s functions to initiate my noospheric link so that we can communicate.> [expletive] <I did not even know I had a noospheric link!>

Exasas-tactical [rhetorical]: <Why else would you have been gifted a godplate if not to become closer to the Machine-God?>

Ghelsa-tributai: <I do not understand why you have contacted me.> [inquiry] <You have Sushus-Gan – why not use her to help you?>

Exasas-tactical: <Though Sushus-Gan is currently uncorrupted, that cannot be guaranteed for the future. She may come under attack via the noosphere and be turned against the Casus Belli.>

Ghelsa-tributai [inquiry]: <But haven’t you just activated my link? Why am I less vulnerable?>

Exasas-tactical: <You are unknown. We data-scraped Olvatia during my brief link with her and registered the inquisitor’s demise. By reviewing archival security data we identified you as a prior companion. The disturbance in the plasma chamber drew our attention and provided opportunity. I have ensured that only physical contact can activate your noospheric capabilities. You will, to put it in a way you will understand, be invisible on the noosphere.> [imperative] <I need you to gather as many of your co-workers as possible and break into the akropoliz. As part of the attack you must free us from the magazine. We will then be able to affect a better resolution to the current situation.>

Ghelsa-tributai [apology]: <Sushus-Gan has already initiated a reactor overload. We would rather destroy the Casus Belli than allow it to fall into the traitors’ hands.>

Exasas-tactical: <I understand. Permit me a moment.>

The presence partially withdrew. In its absence Ghelsa realised that the entire exchange had lasted less than a second. Before she could think about this any further, she felt the re-emergence of the other mind.

Exasas-primary: <I have reviewed the data and I believe there is another way to resolve this attack.>

Ghelsa-tributai [inquiry]: <Can you reverse the overload command?>

Exasas-primary: <I will do so before I relinquish influence over Sushus-Gan. Instead of a full overload I will activate the core leak alarm system.>

Ghelsa-tributai: <That will cause an evacuation of the downdecks.>

Exasas-primary: <Precisely the desired outcome. Olvatia’s augmentatii will also heed the alarm, allowing swift movement from the maintenance sectors to the akropoliz.> [imperative] <You will use the distraction to initiate violence against the augmentatii, and to proceed to the magazine area to free me.>

Ghelsa-tributai [inquiry]: <And if we fail, will you be able to restart the reactor overload?>

Exasas-primary: <There is only a marginal probability that that will be possible. When I reverse Sushus-Gan’s protocols it is likely that heretek tech-priests will seek to close off the system to prevent a repeat attempt at self-destruction.>

Ghelsa-tributai [rebuke]: <You’ll risk the Casus Belli becoming corrupted.>

Exasas-primary: <Yes. I have made a choice. I believe we can save the Imperator.>

Ghelsa-tributai [inquiry]: <Believe? What are the chances of success? Have you calculated them?>

Exasas-primary: <I have not. I am making an assumption. I require your assistance to reverse an absolute-zero possibility of saving the Casus Belli.>

Ghelsa wasn’t sure she could do it. What did she know about leading an attack? Could she even convince the others to take part?

Exasas-primary: <Time is a critical factor, Ghelsa vin Jaint. I believe you are the best assistance I can acquire at this time. Your conduct in the previous hours has shown loyalty to the Casus Belli beyond your duties, and your actions since the rescue of Inquisitor Harkas have shown above-average temperament and determination.>

Ghelsa-tributai [humour]: <Above-average? You’ll make me blush.>

The silence that was forthcoming betrayed Exasas’ lack of understanding, but the joke had bought her the short amount of time she needed to come to a decision.

Ghelsa-tributai [imperative]: <Fake the reactor leak. I do not know how, but I will come for you, and together we are going to save the Casus Belli.>

The renewed wailing of the reactor leak sirens nearly drowned out the snap of weapons fire and the bellows of the downdeckers as they surged along gantries, pounded up stairwells and flowed like a wave from commandeered conveyors. Among them the tech-priests still loyal to the Omnissiah shouted instructions, but it was evident that they were no longer in control. The mob had a will of its own, stirred up by the augmentatii assaults and, after some impassioned pleas, set into motion by Ghelsa.

She had no interest in personally leading the attack, and had kept Exasas’ predicament secret for the time being. First they had to break into the akropoliz, and when that was done she would work out how to rescue the magos.

Before severing the connection, Exasas had activated a chronometer relay inside Ghelsa’s brain. It had been set to fourteen minutes and fifteen seconds, standard chronoscape, which was the amount of time the magos could continue to work through the noospheric systems of the tech-priest ve had suborned to vis purpose. After that, the traitors would know that ve had managed to contact the outside and would reinforce the protection of the magazine or simply execute the former dominus as an unnecessary threat.

Ghelsa was simply aware of the passage of time – it wasn’t a ticking in her head or something she could see. She just knew, as she hauled herself up a narrow stair that curved around the hellstorm cannon mounting, that she only had eight minutes and four seconds remaining.

She passed bodies, both white-coated soldiers and those of tributai and epilekhtoz. It took an effort to remember that they had been people once. It made her wonder if this was how Harkas had felt all the time. Did the humans he had striven to protect simply become statistics weighed against each other?

Ghelsa and the others around her came upon the upper landing, the doors already broken down, a scattering of dead augmentatii in the corridor beyond. Las-fire ahead attracted her attention.

‘Those aren’t radium beams or arc rifle pulses…’

‘What would you know?’ asked Adrina, who had chosen to stay close to Ghelsa for reasons undisclosed. Perhaps it was simply because she was the only one with any sense of what was happening.

‘I spent most of the last day in or near a firefight, one way or the other. Lasguns mean the xenagia. They can help. I hope.’

The corridor split at a junction ahead, serving another stairwell and one of the lower secondary gun turrets. Fighters clad in the dark grey of the Armageddon auxilia held the bottom of the stairs, firing up at targets out of Ghelsa’s line of vision.

Two of them turned as the small mob dashed across the junction, their lasguns raised.

‘Wait!’ shouted Ghelsa. ‘Don’t shoot.’

‘Stay there,’ one of the duct-fighters bellowed back, stress etched into his features, his eyes roaming from one duluz to another. ‘Stay back!’

‘I need you to contact Aszad or Dazi,’ Ghelsa said, trying to sound in control. ‘Have you got a voxhailer?’

‘Don’t need one,’ said the other Armageddonite. She looked back up the stairs and shouted, ‘Lieutenant Aszad!’

A fresh flurry of las-fire from unseen combatants above lit the stairwell. A few seconds later, the tunnel fighter who had saved Ghelsa from the traitor legionary came dashing down the steps.

‘What is it, Kuduza? They’re countering along the third level.’ He saw Ghelsa and stopped, his eyes narrowing. ‘What are you doing here?’

‘I need your help,’ Ghelsa said hurriedly. She stepped closer and dropped her voice as much as she could and still be heard above the shouts and gunfire echoing down the stairs. ‘The rightful dominus has been taken prisoner by the hereteks.’

Aszad looked at her with his head tilted. His gaze moved to the others from the downdecks.

‘Can you pull a trigger?’ he asked, and was answered with nods and calls of assent. He jabbed a finger towards the bodies close at hand and then to several corpses in the doorway of the gun tower. ‘Good. Get a weapon and follow me.’

Some of the duluz were more eager than others. A few looked with distaste at the corpses and slunk away, the rush of blood that had carried them this far dissipating in the cold truth of battle.

‘Dazi is two levels up, but the enemy have split us. Where is the dominus being held?’

‘The main battery magazine,’ said Ghelsa. ‘I don’t even know if ve was guarded – ve was locked in.’

Aszad puffed out his cheeks as he contemplated his options.

‘You and you’ – he nodded to the other duct-fighters – ‘take these new volunteers up to the fighting. Vox the major and tell her I’m coming another way. Get her to push towards shaft four. Ghelsa, you should come with me.’

He headed under the lowest flight of steps while others pounded up the stairs with the auxilia. There was a hatch set into the wall, just about large enough for Ghelsa.

‘The hereteks have been sending armed servo-skulls into most of our ratways, but this one should be fine.’

‘Should be?’

‘There are no certainties in battle, Ghelsa.’ The ring lock creaked as he turned it, but the door opened almost silently on its heavy hinges, revealing a lightless round tube running vertically past the opening.

‘Where does it go?’ asked Ghelsa, leaning forward for a better look. She felt warm air rising, and the metal below them was lit with a faint ruddy glow. Above, she saw a paler light beyond a grille some distance away. Aszad pulled her back with a hand on her arm.

‘Down into the lower incineratum, from the forward maintenance temple.’ He twisted and stepped into the space, his legs braced across the drop. Ghelsa could barely see him as he started walking up, his back sliding against the wall of the chute.

‘I don’t expect anyone is going to be dropping rubbish down here during a battle, but best not dawdle.’

Ghelsa slipped her multi-tool into its sheath and inspected the tube. There was no sign of handholds – she would have to ascend like the duct-fighter, though she was far bulkier.

More gingerly than the Armageddon veteran, she placed a foot on the lip of the entrance, turned and pushed back, expecting to lose her footing and plummet into the flames at any moment.

She felt the metal of the tube on her back and straightened as much as possible. Barely lifting her foot away, her exo-skeleton wheezing, the bars scraping metal as she moved, Ghelsa slid up her free foot, her arms braced to either side.

She looked up – Aszad nearly eclipsed the light from the grille at the top, almost at his destination.

‘All I’ve done today is climb things,’ Ghelsa muttered. Seven minutes and forty-eight seconds remained. Grunting with effort, she started to walk up the waste duct, her strides lengthening as her confidence grew.

Chapter 13

The Final Battle Begins

There was little else Exasas could do except wait to see if Ghelsa vin Jaint and the improvised army of duluz and xenagia could prevail. It had been a significant risk, operating through the tech-priest Sushus-Gan, but circumstance had allowed no alternative.

Now ve allowed verself to gradually seep out into the noosphere again, assembling a datafeed from a thousand tiny contacts. It took several seconds to establish coordinate links, but once Exasas-tactical was able to permeate the noospheric membrane of one of Olvatia’s coterie, the wider systems of the Imperator rose like glorious celebration lights before ver.

What ve discovered was discouraging. One of the Legio Fureans Reavers had returned from the pursuit of the Warhounds. Whether this was due to success or continuing failure was unknown. Two Legio Metalica Warlords – the Omnissiah’s Temper and Indomitable Guardian – had emerged from the storm and a furious battle raged to the left of the Casus Belli between the evenly matched forces. Void shields shimmered, battered with energy and shell by their opposing counterparts, while in the distance the traitor Reaver hurriedly returned, full power directed to its motive engines.

Exasas-secondary [theory]: <There is a high probability that the followers of the Eightwards Way expected to have full control of the Imperator by now. If not for the rebellion in the lower decks, the Casus Belli would be firing upon our former companions.>

Exasas-primary: <Even so, the field is unfairly set. If the Legio continues to arrive individually they will pose no significant threat to the traitors. The decision to avert destruction of the Casus Belli is vindicated if we can restore order.>

A barrage of rockets soared across the desolate basin and engulfed one of the Tiger Eyes Titans in a cascade of fire and smoke. Flickers of purple void shield energy flared through the deluge. On the very edge of awareness, the Casus Belli hungered for action, infecting Exasas with warrior-thoughts.

Exasas-Secondary: <It is not enough to prevent the intervention of the Casus Belli. We must deliver the Imperator back to the service of the Legio Metalica or simply stand witness to the destruction of the battle group.>

Exasas-tactical: <It is likely that as well as Titans, the Legio Fureans has brought heretek-guard for support. In time they will be able to board the Casus Belli and achieve what we have so far denied Gevren, Olvatia and their fellow traitors. Time is not our ally.>

Exasas-primary: <The command module will be sealed against us. Security protocols have changed. It is impossible to control the Casus Belli external to the princeps and moderati stations.>

Exasas-secondary: <I will devote myself to analysis of this problem.>

The persona faded into near obscurity, leaving Exasas to monitor the ongoing battle.

Having realised that the Casus Belli would be of no assistance, the two Legio Metalica Warlords had closed together and merged shields. Their advance was slowed by the manoeuvre but they plodded onwards, attempting to bring their shorter-ranged and close-combat weaponry into action against the traitors.

The Legio Fureans pair split, breaking left and right to come at the faithful engines from both sides. This divided the Warlords’ fire, rendering half of their weapons useless unless they turned to focus on one of their attackers, which in turn would expose their backs to the other.

With the traitor Reaver still closing, the Legio Metalica god-machines turned back-to-back, each concentrating what fire they could on a circling Warlord. Doubtless they were desperately broadcasting reinforcement requests into the stormfront and hoping that more of the Legio would soon emerge before they were outclassed.

Merging the shields appeared to be working for the time being. Giving each Warlord in effect twelve void shields granted them time to repair overloaded generators before their full energy defences were overwhelmed. The overlapping domes of power and conflicting energy signals made it hard to discern exactly how many banks of shielding they had left, but Exasas estimated it was eight or nine.

With a burst of scintillating red, the Reaver unleashed the twin beams of its turbo-laser destructor. The paired pulse screeched across Casus Belli’s sensor array and struck the Warlords’ shield wall. Within the coruscating hemispheres, Exasas detected energy spikes that signified a double overload.

Six shields left, ve decided, erring on the side of pessimism.

The edge of the storm not far behind the Imperator was a wall of blankness on the scanners, described in negative by the continual flickering of electromagnetic discharge. Exasas sifted through the data for any sign of approaching Titans – as no doubt the tech-priests in the czella were also. It was impossible to tell what was a storm strike and what might be the energy signature of a plasma reactor.

In the ongoing battle, it appeared that the two faithful princeps had decided to do as much damage to the enemy as possible before they succumbed to the inevitable superiority of their opponents. War sirens howling their resistance, they turned together, bringing their largest guns to bear on the incoming Reaver. Gatling blaster rounds screamed out from the Omnissiah’s Temper while its companion powered up a devastating shot from its plasma destructor. The simultaneous impacts enveloped the traitor Reaver in a hemisphere of blue fire, the cataclysmic energy surge blotting it from detection for several seconds. In the following moments the Indomitable Guardian broke from the Omnissiah’s Temper and turned to face directly towards the Legio Furean traitor.

In place of the czella command module, the Warlord had a centreline deathstrike cannon, the moderati and other command crew relocated in a special control tower mounted upon the carapace. The cannon, more properly suited to bombarding fortifications, erupted with a single blast of thunderous anger. Exasas tracked the shell’s progress via the Casus Belli’s detector screen, following its trajectory directly into the Reaver’s chest.

The detonation physically buckled the enemy Titan, causing it to step backwards, its princeps struggling to maintain balance. Burning oil fell like fiery blood from the gaping rent in the Reaver’s chest, a storm of sparks and the gleam of venting plasma lighting the wound from within, quickly blotted out by a pall of black smoke.

Exasas shared a moment of triumph with the Casus Belli as the magos saw through the Imperator’s artificial eyes the Reaver toppling sideways, its hip shearing away under the incredible torsion of its displaced weight. Another volley of gatling blaster fire raked into the carcass, thudding anti-tank shells into the head and exposed central cavity.

The sensation of achievement was short-lived. Excoriating las-fire from the remaining traitors surged across the Indomitable Guardian’s last void shield, the final beams of the salvo striking welts across the red-painted carapace. Exasas sensed the power build-up of a volcano cannon readying to fire, preparing an execution shot.

Princeps Udrasda of the Omnissiah’s Temper evidently judged the same. His Warlord surged forward, void shields crackling as the crew within called upon the miracles of the Machine-God to protect their engine.

The Omnissiah’s Temper interposed itself between the firing Warlord and the Indomitable Guardian as the volcano cannon snarled its deadly beam. Instead of punching through the head or reactor of the stricken Warlord, the beam of energy crashed against operational void shields, its Titan-slaying power diverted into the warp for the relatively minor cost of another overloaded generator.

Two Warlords faced two Warlords, though the Legio Furean engines had restored most of their shields. Exasas’ thoughts returned to the absent traitor Reaver and the two Warhounds of the Legio Metalica. A circumspect analysis of the communication datalogs revealed nothing that could point to the fate of the other engines, and hence which, if any, might return to swing the balance of the ongoing battle.

Aszad crouched at the top of the trash channel, the grille pushed aside. He offered a hand and then withdrew it as Ghelsa hauled herself into the maintenance temple. The auxilia signalled for her to be quiet with a finger to his lips.

Ghelsa had never been inside such a place before. It was bedecked in friezes like much of the akropoliz, the images depicting manufacture and construction. She recognised several vistas from Metalica, though she had never been there. The immense domes of the Oraculuz of Delvi where immense defence satellites were constructed, the launch fields that sent them up to orbiting transporters a flat expanse the size of a small town beside them. A girder-wreathed tower was the forgeworks at Nyziroz, erected atop the summit of an active volcano, the lava channels down the slope flanked by machinery and forge-levy.

Among the artistry stood lines of benches laden with disassembled weapons, pieces of armour and cybernetics. Lascutters and sonic drills hung on racks alongside microforges on jointed legs, while from the ceiling drooped a profusion of cables ending in lenses, blades and equipment beyond Ghelsa’s interpretation.

They had emerged in a corner of the chamber, which connected to another via a broad archway whose lintel was inscribed with Metalican runes. Ghelsa could not read them, but assumed they were some prayer to the Omnissiah or a blessing of the Machine-God.

‘Nobody home,’ she said, remembering to keep her voice down all the same. ‘The climb wasn’t easy, but no obstacle for tunnel fighters. Why haven’t you come through this way before?’

‘We tried,’ Aszad said, and pointed towards the next chamber.

Through the legs of a bench just on the other side of the arch Ghelsa saw a grey mass. It took a few seconds for her to translate what she saw into two bodies, one atop the other. Blood had dried on the floor around them and there were splinter marks and craters on the far wall. Ghelsa’s mouth went dry and she found it difficult to swallow, her grip suddenly greasy on the multi-tool.

Aszad motioned for her to follow and scuttled crabwise away from the duct opening, using the bulk of a dormant generator for cover. Doubled over, Ghelsa followed. At the lieutenant’s prompting, she hazarded a glance over the generator, past the coils of wire and tubes on its top.

Through the arch was a chamber similar to the one they were in, an open security door in the far wall. She spied more xenagia corpses among the broken remains of half-complete repair projects and shattered tool boxes.

In front of the door stood a quadruped war engine, filling the space with its bulk, two heavy cannons on its shoulder mounts and a variety of bloodstained close-combat weapons protruding from around its armoured carapace. An assortment of detectors and lenses tracked slowly back and forth between the doorway and the maintenance chamber. She recognised it immediately.

‘That’s Magos Exasas’ battle-form.’

Aszad nodded.

‘I don’t know if it activated itself or was deliberately set up as a sentry, but it’s been guarding that door since the fighting spread into the akropoliz.’ The lieutenant pointed to an open furnace door on the right, the interior dark. ‘If we can get in there, the flue leads up another level.’

‘If your troopers couldn’t move fast enough, there’s no way I can,’ said Ghelsa. The tributai noticed more bodies in the corridor outside, swathed in the white coats of the skitarii. She shook her head. ‘No, I’ll never make it.’

She sat back on her haunches and turned, resting her back against the generator. As she was wont to do when thinking, she idly tapped a metal-tipped finger against her godplate. Between taps, she stopped, struck by a sudden intuition.

‘Do you think you could distract the battle-form long enough to allow me to get close to it?’

‘How close?’

‘Touching distance.’

Aszad shrugged, head tilted. ‘I don’t know. We didn’t try that – it would cut you in half the moment you were within reach.’

‘But can you get it to focus on you?’

‘I…’ Aszad thought about it for a few more seconds and shrugged again. ‘I think so. If you don’t have a weapon and I’m shooting at it, I’ll be a much greater threat. It might even think you’re a non-combatant.’

‘Or it might not…’ said Ghelsa. She moved to the left-hand side of the generator and pointed for Aszad to go right. ‘If this doesn’t work, promise me you’ll try to rescue the magos.’

‘I promise,’ said the lieutenant, though Ghelsa had no idea whether he meant it. ‘Go.’

The sight of flames licking along the left side of a traitor Warlord briefly lifted Exasas’ spirits until vis focus returned to the parlous state of the Indomitable Guardian and Omnissiah’s Temper. They had only survived the last minutes through some deft work by their tech-priests and princeps, all but giving up any pretence of offensive action in return for additional power to the void shields and motive engines.

Working as a pair, one would remain stationary and fire at the flanking Warlords while the other retreated a short distance towards the storm. They would then exchange roles, with the other providing a modicum of covering fire for the withdrawal of their companion.

It was a false hope.

Exasas was a magos, not a princeps, but had been present at enough Titan battles to have analysed the most efficient tactics. It would be only a matter of time before the traitor princeps reacted to the lack of incoming fire and became bolder in their attack. Faced with more assertive opposition, the two loyal Warlords would have to either respond, requiring more weapons power, or simply wilt before the overbearing firepower that would be directed at them.

Even so, it seemed that the Tiger Eyes princeps were more concerned with cutting off the Warlords’ retreat than they were with their immediate destruction.

Exasas-tactical [theory]: <They have become over-confident. Greedy. They wish to capture rather than destroy.>

Exasas-secondary: <I disagree.> [theory] <When viewed from the strategic perspective, the enemy are cautious because they are unsure whether our Titans will receive reinforcement from within the storm.>

Exasas-primary: <That would be a cause for a more optimistic appraisal of our chances. Firstly, that the enemy are equally hampered by the storm’s sensor-breaking effects and have no advanced intelligence on what has happened to the remainder of the battle group. Secondly, even with that limited data they believe it likely that more engines of the battle group will exit the storm soon.>

Exasas-secondary [datalog]: <Optimism is rarely rewarded.>

The data-packet directed Exasas’ attention to the long-range sensor scans. A plasma reading approached, still distant but unmistakably too significant for a Warhound. Whatever had transpired further into the mountains, the second Tiger Eyes Reaver was returning.

The uncertainty around the fate of the Warhounds swiftly became a near-zero probability of survival as more and more readings flowed into the Imperator’s sensor banks. Individual signals were too small for identification at this distance, but what was clear was that a large number of vehicles followed the returning Titan.

The Legio Fureans’ heretek-guard had landed and were en route to the battle.

Exasas-tactical expanded into control consciousness, directing awareness to a very local signal in the noosphere, shunting aside the battle-data. Ve had been monitoring the ongoing fight through the akropoliz as well as ve was able given the secondary nature of the datafeed, but an incident not far from the main battery had triggered proximity interest.

A number of augmentatii were being forced back by a concerted assault. Exasas-tactical was unable to get a direct feed from any of the battle-shielded alphas, the protocols rearranged by Olvatia’s command. Instead ve had to rely on flickers of information from the Casus Belli’s internal monitoring system and occasional witness data from the emanations of unshielded tech-priests in the vicinity.

Further investigation suddenly ceased. At the same moment that Exasas felt the noospheric links rebounding towards ver in a wave, ve registered that the chronometer deadline had been met.

Ve was out of time.

In the main battery above, Mithras-4 sensed the intrusion of the magos’ noospheric aura. The connection severed almost immediately, but not before Exasas detected the backwash of an alarm pulse. The coded content was unknown, but from vis contact earlier ve was able to identify the destination: Olvatia.

Though the all-encompassing background thrum of the noosphere remained, it was as though a transparent curtain had been dropped across it, allowing sight but not touch.

Exasas-primary: <We are being actively sought. Our attempt to gain freedom has failed.>

Exasas-tactical [imperative]: <Hide!>

Exasas dropped down from vis precarious position, turning mid-air to land heavily on the uppermost level of the rampway. Minor damage shocks to vis limbs shuddered through vis system.

Below, the magazine shell doors ground open, the shadows of the augmentatii outside cast into the interior. Exasas shrank away from the edge, trying to avoid being seen while ve extended vis auditory sensors, hearing every footstep as the guard squad entered.

‘You have been judged heretek, Magos Exasas,’ the alpha declared, the modulated voice echoing up the hall. ‘Submit to immediate execution or suffer more prolonged torment. You have twenty seconds to comply.’

From the overlapping sound waves caused by the footfalls of the augmentatii, Exasas was able to estimate the position and progress of the firing squad. Four moved towards the base of the rampway and the rest spread around the inner vault casing, probably searching for the magos.

Ve withdrew vis sensor tendrils as far as possible, not wishing a twitching antenna to betray vis location. This came at the expanse of clarity, the tread of boots reduced to an omnidirectional sound. Constrained thermal registers detected only the presence of cybernetically altered humans within the chamber, nothing more detailed.

In minutes they would find ver and kill ver.

Ghelsa hurried forward on all fours, moving from bench to bench to keep out of sight of the battle-form. Even so, she heard the whirr of its servos as it turned into the room, the thud of one foot adjusting position as non-visual sensors detected her presence. A growing whine reminded her of an overheating power cell and she realised it was the phosphor serpenta warming up.

A snapping noise announced Aszad’s diversionary shots, the red flare of lasbeams reflected from the metal surfaces all around Ghelsa. Pushing up into a crouch, she moved closer.

A rapid thunder accompanied the battle-form returning fire. The billow of flames lit the chamber behind Ghelsa and she hurried forward, feeling the wash of heat on the back of her neck.

Scuttling left as best as her exo-skeleton allowed, the tributai moved closer, trying not to picture the gleaming power blades and whirring chain-weapons that would lash out to meet her.

A bass throb heralded a salvo of fire from the macrostubber, followed swiftly by the ring of punctured metal and shattering glass. Still the tinny zip of Aszad’s lasgun kept up a slow but steady rhythm, assuring her that the duct-fighter was still alive.

She eased herself under a desk not far from the doorway, her eyes fixed on the plated armoured shapes of the battle-form just in front of her, its clawed feet clanging on the floor as it repositioned again.

Ghelsa waited, struck by a sudden doubt. There was nothing to even suggest her plan would work.

Nothing better suggested itself and, now that she was committed, she had no choice but to follow through.

Suppressing a shout, she launched herself out from under the desk, bare feet clinking through discarded shell casings. A red-lensed sensor swung towards her. She ducked beneath it, arms outstretched, and threw herself at the battle-form’s armoured flank.

Hands slapping on cold metal, she pushed her head against its metal skin, offering up a silent prayer to the Machine-God to guide her thoughts to the spirit of the battle-form.

As her godplate touched metal she felt the surge of noospheric connection, and in the next moment was dragged into the angular thought mechanisms of the battle-form’s residual persona.

Ghelsa-tributai [imperative]: <Cease fire! Stand down!>

Exasas-local [inquiry]: <Authority for command?>

Ghelsa-tributai [datalog]

Exasas-local: <Exasas-tactical authority accepted. Complying with command.>

With a gasp, Ghelsa rolled away, almost falling to the floor in relief. Steadying herself against a charred bench top, she looked back into the other chamber, seeking Aszad. The battle-form’s fire had trailed ruin across most of the maintenance hall. Flames licked from severed gas lines and sparks fizzed from broken wires while pools of chemicals bubbled and hissed from broken crucibles and vats.

She saw the top of a head poke hesitantly over the bullet-riddled remains of a kastelan’s shoulder plate that had been upturned as a shield.

Wide-eyed, Aszad stood up, lasgun in hand.

‘How did you do that?’

‘It doesn’t matter. Can you contact your troops?’

‘Do I look like I have a voxcaster?’

Ghelsa was painfully aware of time passing. Two minutes and three seconds remained until Exasas’ unauthorised noospheric link would be discovered.

‘What would you call it when you’re ordered to accompany someone and defend them at all costs?’

‘I’m not sure,’ said Aszad. ‘Personal protection detail, I think. It’s not the sort of mission you give a tunnel fighter.’

‘I wasn’t thinking of you,’ said Ghelsa, and she pressed her brow against the battle-form.

A sudden burst of fire rang up the magazine walls, accompanied by the unique detonation signatures of phosphor rounds. Exasas flinched, expecting to be engulfed in fire, but vis temperature sensors indicated the impacts were not in vis locality.

Arc rifles buzzed in response, accompanied by shouts of anger and a highly distinctive zip of lasgun fire.

Lasguns were not standard issue of the augmentatii.

Edging towards the rim of the rampway, keeping as low as possible, Exasas extended a solitary visual sensor over the boundary of the platform.

Three of the traitor soldiers were scattered bloodily across the floor, body parts still burning. More phosphor rounds and a blaze of macrostubber bullets flashed into the magazine from outside the doors, immolating and shredding two more augmentatii. A stab of lasgun fire hit a third in the shoulder as the augmentatii returned fire with a radium carbine.

Another deadly salvo raked through the survivors, impacts from the macrostubber chasing the last of the augmentatii until it caught her at the bottom of the ramp, tearing through coat and armour. Punctured with bullet wounds, the augmentatii managed to cling to existence for a few seconds more, crawling upwards, propelled by her last incoming command, until a final zap of arc-rifle fire finished her off.

Exasas was surprised to see vis warskin clatter into view, smoke issuing from the muzzles of its guns, close-combat weapons buzzing and gleaming. Surprise became shock at the sight of a human riding on its back. She was dark-skinned, encased in the struts of a full metaphysical exo-skeletal frame.

Ve recognised the tributai – Ghelsa vin Jaint. Behind her came a xenagia officer, his lasgun sweeping across the downed augmentatii, wary of any survivors.

‘They are all dead,’ announced Exasas-tactical, uncoiling vis bodyform to its full extent. Ve lifted an appendage over the edge of the ramp to attract their attention. ‘No life signs detected.’

‘Praise the Machine-God,’ called out Ghelsa vin Jaint. ‘You’re still alive.’

She jumped down from the back of the warskin and started towards the ramp. The warskin followed just a few steps behind, weapons poised. The duct-fighter moved back to the doorway, leaning out to check that all was well.

Exasas raced down to meet them, almost losing vis footing on the slope. Ghelsa vin Jaint waited at the bottom, rifling through the augmentatii dead, plucking spare energy cells to reload her arc rifle. As ve neared the warskin it reared up like a hunting arachnid, poised to attack.

‘Stand down,’ said Ghelsa vin Jaint, patting it lightly on the flank. The warskin… relaxed? Exasas had never seen such a thing. Ve tried to contact it via the noosphere but the blocker was still in place.

‘We need to create lateral distance from the origin of the noospheric interference,’ Exasas-primary told the tributai.

‘Follow us,’ she replied, glancing at the Armageddon officer and receiving a nod of affirmation.

Together they moved out into the corridor and turned left, with the tunnel soldier leading the way, Ghelsa vin Jaint and the warskin just behind. Exasas pulsed connection signals to vis battle component and could feel the break of static lessening, but it was not until they reached the corpse-littered conveyor hall next to the magazine that ve was able to make a full connection.

The first sensation was recognition from the warskin. Exasas slipped aside the personal protection command installed by Ghelsa vin Jaint and partitioned Exasas-tactical to take control. Even as the warskin turned and segmented open to allow the magos to enter, vis noospheric awareness synchronised fully with the systems of the Casus Belli.

At the touch of the Machine-God’s breath, Exasas’ thoughts ascended.

Exponential dataflow coursed through vis systems, appraising ver of all that had happened in the ongoing Titan battle and the fighting within the Imperator. The data was intoxicating after ve had been cut off from its direct flow, and Exasas released excited puffs of bacteriophagal incense. Compared to raw audio, tactile and visual stimuli, the noosphere was a light of the heavens shining down into vis systems.

Outside, a Reaver loyal to the Legio Metalica had arrived from the storm, its presence enough to drive away the two renegade Warlords. In the face of the continued abstention of the Casus Belli and the incoming full skitarii battle group, the Iron Skulls princeps faced a hard choice – remain to fight or retreat into the storm. To do the first seemed suicidal, but to enact the second would abandon the rest of the battle group to the waiting traitors. Flashes of communication between the Titans indicated the continuing debate.

Exasas-secondary: <I shall dedicate myself to the monitoring of the external situation and process relevant feedback.>

Within the Casus Belli the news was equally disheartening. Although the shock of the duluz uprising had carried into the akropoliz, the roused workers were simply no match for the trained, coordinated squads of augmentatii and skitarii that faced them. Just as with the Heretic Astartes’ assault, the defenders of the Imperator were linking up and systematically clearing each level of the akropoliz.

‘Dominus,’ said the Armageddon veteran – identified as Lieutenant Aszad of the Second Defence Platoon – touching a hand to his brow as he approached the tech-priest. ‘Major Dazi’s forces are holding well but need support. We need more guns on our side. Can you resume command of your skitarii?’

Exasas tried to make contact with the closest alpha, but Olvatia’s protocols had modified their axonic signals so that they did not recognise the former magos dominus’ impulses.

‘At present, I cannot,’ the magos confessed. Ve saw Ghelsa vin Jaint and Aszad sag with disappointment. ‘That does not mean it is a zero-probability phenomenon. I need physical contact with a living alpha to regrade the security pathways. Then I will be able to restore the former command protocols and resume control.’

‘A living alpha?’ Aszad scratched his stubbled chin in thought. ‘Right. Wait here.’

Slinging his lasgun across his back, the tunnel fighter opened a narrow maintenance grille in the wall between the conveyor shafts. Like an arboreal mammal, he shinned up the cables within and disappeared out of sight.

Exasas-secondary [datalog]: <It would appear that the Omnissiah’s Temper, Indomitable Guardian and Victorious Endeavour have chosen to remain and fight. It is impossible to know whether this is based on positive experience within the storm that more of the Legio Metalica will arrive shortly, or simply hope.>

Exasas-primary: <I believe they are correct at the present time. Their proximity to the storm allows them t–>

A sudden outflux of data into the noosphere shivered through Exasas. It felt like razor-sharp blades through vis soul, slashing across the circuits of the Casus Belli to infect every system. The sensation was of a billion fragments breaking apart and then reassembling, but not in quite the same construction. Power lines that had been left dormant by the exodus from the lower decks suddenly thrummed into new life. Autoloaders clanked into action and gun turrets moved like a pugilist flexing their muscles before a bout.

Exasas-tactical: <The enemy have pierced the Imperator’s battle-shielding and are reworking the machine-spirit code. They are activating systems independently.>

One by one all twelve of the void shield generators came online, the crackle of their activation heard as well as felt. All across the Casus Belli, slaved servitors and their tech-priest attendants were succumbing to the infiltrating codewave.

A tangible shudder announced the motive engines firing as plasma again coursed through the great conduits of the reactor.

Exasas could feel the spirit of the Casus Belli, like a distant moan of frustration and pain.

Exasas-primary [theory]: <This is not an assault through the battle-shielding. Someone has introduced a secondary spirit-code into the systems.>

Exasas-secondary [rhetorical]: <Someone? It must be the princeps senioris and moderati. The Casus Belli has been resisting their efforts and now they are attempting to erase the Imperator’s spirit with an artificial codeware.>

Exasas-tactical: <Source is irrelevant. The Casus Belli will be war-active within minutes. One salvo of full weapons fire will destroy the remaining loyal Titans.>

Metal knuckles rang on the shell of Exasas’ warskin. Ve detected Ghelsa vin Jaint on the left-hand side, staring up at the cluster of detector appendages. She looked concerned.

‘What is happening, magos?’ the tributai asked. ‘Why is the Casus Belli coming alive without crew?’

‘I am analysing the situation,’ replied Exasas. ‘A foreign spirit has been introduced to the Imperator to override normal protocols.’

The ring of a bell announced the arrival of a conveyor. Both magos and tributai turned towards the door with weapons raised.

The shutter slid back to reveal Lieutenant Aszad, a white-coated figure slumped on the floor at his feet. Exasas detected fresh wounds on the tunnel fighter’s face and bloodstains on his clothing that had not been present when he departed.

‘One alpha, as requested,’ he said, rolling the inert figure from the conveyor with his foot.

Exasas examined the unconscious squad leader and identified him as Alpha 4-Ajax. Ve peeled apart the warskin and flopped out, vis manipulators turning the alpha over and pulling down the soldier’s hood to expose the physical sockets in the base of his skull. Exasas slid a data-spike into the opening, elicting a gasp from the squad leader as ve interfaced directly with the alpha’s cortical network.

#identify#magosdominuscommandvalveopen#magosdominuscommandvalvearticulate#replotmagosdominusprotocolcommand#identify#

Withdrawing the spike, Exasas moved the squad leader to a sitting position and wheezed a cloud of invigorating incense. Bionic eyelids clicked open and the natural organs within took a moment to focus. Bright blue eyes fixed upon the magos.

‘Dominus…’ muttered the alpha. A sudden expression of dread marred his young features and he fell forward to his knees, pressing his forehead against the deck. ‘Forgiveness, dominus, for I have transgressed your authority.’

‘Forgiveness is delivered,’ said Exasas, and he laid a tendril-limb upon the alpha’s shoulder. ‘The malignancy is Magos Olvatia’s – you had no choice but to obey. Stand.’

The alpha regained his feet and looked around as though seeing Lieutenant Aszad and Ghelsa vin Jaint for the first time. It was standard protocol-induced amnesia, activated to prevent recollection of previous orders in the event of… in the event of someone doing exactly what Exasas wanted to do.

‘I need you to become a broadcast hub for me, Alpha 4-Ajax.’

‘Of course, Dominus, I am willing to lay my spirit aside for your victory.’

Alpha 4-Ajax turned around, exposing his neck-sockets again. Exasas physically synchronised once more, but this time, rather than imparting code, ve archive-stripped everything from the alpha, hollowing out his personality and soul. In its place the magos inloaded a loop broadcast program of the data-packet ve had transferred to break Olvatia’s protocol wall. The last thing ve imparted before withdrawing the data-spike was a constant-motion imperative, which sent the alpha towards the stairwell at the end of the hall.

Ghelsa vin Jaint and Lieutenant Aszad watched the alpha stride away.

‘What did you do, dominus?’ asked the tributai.

‘He has become a beacon for me,’ Exasas answered, trying to choose the correct words to convey the complex noospheric process ve had just initiated. ‘A recruitment algorithm that will spread to all of my former skitarii and replicate itself. I am confident that within fifteen minutes my surviving soldiers will have been returned to my command.’

They felt the akropoliz lurch as the Casus Belli took a first stride.

‘I don’t think we have fifteen minutes, dominus,’ said Lieutenant Aszad. ‘We’ll all be dead by then.’

Exasas-tactical: <The officer’s assessment is highly probable.>

Exasas-secondary: <The battle group will not survive a period of fifteen standard minutes.>

Exasas [affirmative]

‘Rally such troops as you can, lieutenant. I will do my best to coordinate the reawakening skitarii with your actions. It is a priority that we force access to the antae so that we can disable the command crew.’

‘Ghelsa, you should stick…’ Lieutenant Aszad did not finish what he was saying, because Ghelsa vin Jaint was no longer present. Their attention was drawn to a clank of chains as the nearest conveyor shutter closed. A moment later engines whined into action and the cage disappeared.

‘Where do you think she’s going?’ muttered the tunnel fighter.

‘Unknown, lieutenant. Perhaps she has experienced too much trauma and wishes to avoid further conflict. She is tributai, after all, not skitarii or xenagia. She was created to serve the Machine-God as a mechanic, not a warrior.’

Chapter 14

Servants of the Machine-God

Not quite sure what she was going to do, or where she was going, Ghelsa rode the conveyor down several levels of the akropoliz. She switched out the power cell of her arc rifle as Aszad had shown her. Her knowledge of the layout was patchy, most of it gathered during her flight with Harkas. And for most of that she had been more concerned with staying alive than with studying floor plans.

The atmosphere of the Casus Belli had changed, and not just in perception as when she had fled into the downdecks earlier. For a start, through her awakened noospheric circuit she had a greater awareness of the Imperator’s soul pressing around her like the weight of a mountain. Even though she did not touch it directly, she could feel its energy coursing through every system, carried in thought the same way energy was carried in electricity from the plasma reactor.

Beyond that, she could also feel that there was something tainted in the machine-spirit. Like a blot of oil on a uniform, it was seeping into the weave of the Casus Belli’s soul. Ghelsa was not sure how she could know this except to believe that the Imperator was reaching out, sharing its pain with any mind that would listen.

The conveyor screeched to a halt at the level she had selected – somewhere close to the atrium, she thought. Letting the shutter door roll up, arc rifle held awkwardly in one hand and multi-tool in the other, she stepped out and found herself on an open mesh gantry that ran across from the central tower of the akropoliz’s main battery to the secondary turrets. She looked down and saw fighting among the buildings where Olvatia’s augmentatii – she recalled the term from Exasas’ datalog – chased down groups of tributai and epilekhtoz.

The sky moved as the Imperator turned, and it was then that she laid eyes upon the Titan battle raging beyond the void shields. Blasts that could have levelled city blocks flared between the energy-wreathed god-machines. Salvos of shells and missiles the equal to a company of tanks spat and sparked from their energy defences.

The Casus Belli was turning towards them. It was ungainly and slow, the corrupting spirit introduced into the system not used to its immense metal body, perhaps having to fight against the Imperator’s incumbent soul. Even so, it would not be long before the plasma annihilator would be brought to bear, and then the weight of all the other guns atop the akropoliz.

She tore her eyes away, the sense of urgency that had sent her on this ridiculous mission renewed. She ran back into the conveyor, slammed down the shutter and hit the descent lever again. Armed with the view from outside, she had a better idea of where she was, and knew she had to move forward to reach the atrium.

The conveyor was only a few levels above the antae when she activated the brake and disembarked again. The noise of fighting was a lot closer – or seemed so, though the ring of bullets and crackle of flames was hard to pinpoint among the cross of passages ahead. She saw a flickering light against a wall and ran towards it.

She stopped at the junction and peered round – a squad of xenagia were staving off an augmentatii attack from one of the other conveyor halls. Ghelsa dashed across the corridor as stray shots hissed past her, spraying phosphor sparks as they thudded into the walls and ceiling.

She continued on past an empty weapons store and the magazine for a secondary turret, before coming out near the top of the atrium. She knew little of how to read a battle, but it appeared there was something of a standoff across the upper levels. Both sides had erected rough barricades across several access corridors and were sniping at each other.

Keeping low, Ghelsa hurried behind the groups of workers manning the improvised barriers, clutching the arc rifle to her chest to stop it tripping her. She reached the end of a line of empty munitions crates and crouched, stealing a look down into the depths of the atrium. As she had hoped, the large forms of several kastelans stood before the antae, their weapons trained up at the fighting above but silent. She wasn’t certain what prevented them from participating, but assumed that they simply could not cope with the thought of the faithful fighting the faithful and therefore could not separate legitimate targets from allies. Olvatia obviously had not been able to redirect their programming in the same way she had overridden the command hierarchy of the skitarii.

Getting down to them looked like a difficult and time-consuming run down the levels, until Ghelsa hit upon a better – at least swifter – means to negotiate the descent.

Exasas-tactical: <I am uncertain why this did not occur to us previously. My mono-tasked status was an oversight.>

Exasas-primary: <Your mono-tasked status was deliberate. You are intended as a primary battle-persona, operating without distraction. The very fact that this exchange is occurring denotes that the purpose for which you were created has been undermined.>

Exasas-secondary: <We should establish whether a synchronised ability to evaluate both tactical and strategic datastreams is more beneficial than a wholly mono-tasked operational persona.>

Exasas-tactical [negative]: <But not at this juncture.>

Exasas-primary [negative]

Exasas-secondary [negative]

The magos tore apart the augmentatii gripped in two of vis combat claws and studied the glutinous liquid that spilled from the two halves. The whirring teeth of a different attachment decapitated another, spilling more of the fluid onto the floor.

Exasas-primary: <It seems to be semi-organic in origin.>

Exasas-secondary: <I am detecting blood-type cell structures. The modification is inefficient.>

A burst of fire from vis phosphor launcher incinerated another augmentatii at the corner of the corridor ahead, the detonation fusing another nearby soldier with her arc rifle.

Accompanied by the xenagia, Exasas advanced to the junction, stopping just outside the gateway to the central battery access stairs. Ve motioned to the left with an appendage.

‘Major Dazi, seize as many battery turrets as possible to prevent the enemy from firing the Casus Belli’s guns.’ Exasas had united several scattered groups of duct fighters, including their commander. ‘Permanently disable them if absolutely necessary.’

‘We don’t have enough troopers to fight through to every gun, dominus,’ replied the officer. ‘We’re running out of time.’

Exasas-tactical: <My calculations show that Major Dazi is correct. We shall gain the upper hand within the Casus Belli, but not soon enough to prevent the Imperator’s intervention from changing the course of the battle outside.>

Exasas-secondary [negative]: <I cannot accept that we have failed while the battle is still being fought.>

Exasas-primary: <No, we cannot.> [theory] <Olvatia may well concede as such. There is a way to save ourselves both time and losses.>

Exasas shut down extraneous systems to send out a broadcast through the noosphere, issuing a challenge to the rogue magos. Ve transmitted vis locational data, the virtual equivalent of daring the other magos to face ver, unconcerned by vis physical wellbeing.

The other dominus reacted instantly, flooding the noosphere with rebuttal data asserting her position in command. Exasas reincorporated all routines, algorithms, antarithms and personas to meet the coming processing demand.

Exasas [imperative]: <Surrender. I offer clemency in return for swift capitulation.>

Olvatia [negative]: <The Casus Belli will be delivered to the rightful command of the Eightwards Way. You cannot prevent this.>

Exasas: <Your personal participation in that victory is not assured. After I have seized control of the Imperator I will ensure not only your termination but a total personality deconstruction. No part of you will exist to enjoy the rewards of your treachery.>

Olvatia [negative]: <You assume your victory.>

Exasas [simulacrum datalog]

Exasas: <I have already won, Olvatia. Now that I control the skitarii and the cybernetika, augmenting the ongoing resistance of the duluz and xenagia, there is an absolute-zero chance of your remaining forces being victorious. The victory will be swifter still without you to guide the augmentatii.>

Olvatia [negative]: <You are mistaken. I am still in command.>

Exasas extended the strength of contact, awakening the security protocols ve had shared with the other magos upon the occasion of vis earlier capitulation. Although ve was unable to pierce the other dominus’ battle-shielding, the proximity of the persona-shard allowed Exasas to violently inload the entirety of vis theorem and accompanying data. The effect was devastating, overwhelming Olvatia’s far cruder simulation circuits with more information than they were destined to process.

#killefficiency95%#

Exasas: <I do not assume.>

Arc rifle slung across her back, Ghelsa clamped her fingers around the closest rail and vaulted over, hanging by one hand. Expecting to be hit by a stubber bullet or phosphor round at any second, she let go.

The clang of her outstretched arms hitting the next rail down was just one noise among many in the din of battle. Ghelsa clung to the rail for a second, steadying herself before she let herself drop again.

It was the hook of her multi-tool that caught this time, swinging her hard into the ferrocrete of the walkway. She winced, tasting blood where her lips had been split, but kept her grip locked about the haft of the tool. Wedging a foot beneath the bottom rail, she unhooked herself and reviewed her progress.

Two levels to go.

Taking a deep breath, Ghelsa fell again. And again.

Dropping to the bottom level of the atrium, she knelt for a few seconds with her head bowed, glad to be on solid floor again. A shadow fell across her, and she looked up into the featureless dome of a kastelan looming over her.

‘Praise the Omnissiah, hail the Machine-God,’ said Ghelsa.

<Identify.>

‘Ghelsa vin Jain, tributai,’ she replied, standing up. She glanced over her shoulder, up at the firefight raging above. The fire from the duluz side of the atrium was definitely waning compared to the fusillade from the other. ‘Contact Delta 6-Terror. Verify my status.’

One of the other kastelans stepped forward. <I am Delta 6-Terror. Status verified, Ghelsa vin Jaint. Categorised as faithful.>

‘What are your current orders in my regard?’

<Protect the faithful.>

‘Can you transmit that order to your maniple?’

The kastelan stood immobile for a few seconds, and then the other four robots stepped up beside it.

<Protect the faithful,> they chorused.

‘I hope this works,’ muttered Ghelsa, and set off up the ramp with her six-strong cybernetic bodyguard.

It did not take long for the augmentatii to spy her ascent. Ghelsa made no attempt to hide herself, striding in plain view of the enemy just ahead of the kastelans. She deliberately made herself a target, pointing her multi-tool threateningly at the renegades.

Please don’t be coy, she thought. If Olvatia’s soldiers realised what was happening, they would not open fire and the whole plan would fail.

There was also the significant chance that the first shot at Ghelsa would kill her. She did not want her victory to be posthumous, but if it took her death…

A phosphor round screamed down, hitting Ghelsa in the leg. It struck her exo-skeleton first and sprayed white-hot fire across her calf and knee. She toppled with a shriek.

She took no comfort from the boom of the kastelans’ return fire as phosphor ate into the protective weave of her coveralls and started melting skin and flesh. Ghelsa scrabbled away between Delta 6-Terror’s legs as more phosphor shells exploded across the cybernoids’ armoured bodies and radium beams sliced down. She dragged herself into a side corridor and flopped against the wall to examine her leg.

The exo-skeleton and coverall had taken the brunt, but a scorched trail from knee to ankle marred the side of her leg, almost down to the bone in places.

She didn’t register any pain. At first she thought it was simply shock, but the more she stared at her leg the more she realised it was something else. The injury should have been crippling, but the surgery that had implanted much of the interior support for her exo-skeleton had rendered the nerve endings numb. But that was not enough to explain the lack of excruciating agony.

It had to be the noospheric circuit, she realised. It was literally overriding the signals from her ravaged limb to her brain, intercepting them before they reached her synapses.

Extending the multi-tool, she was able to use it as a crutch and get to her feet. She tentatively put some weight on her foot, and felt nothing. Fear of pain rather than actual sensation made her limp back towards the atrium, where the kastelans had advanced to the next level behind a pounding volley of fire. The barricades erected by the augmentatii had been pulverised and set on fire by the robots’ barrage, clearing out the next level.

More importantly, the lowest level was free of enemies – the way to the antae was clear. If only she had some way to contact Magos Exasas.

It was then, through the cacophony of phosphor blasters and arc rifles, that she felt rather than heard the rumble of the upper batteries opening fire. The Casus Belli had turned its guns on the other god-machines of the Legio Metalica.

Reeling from the inload, Olvatia’s defence protocols initiated, conceding the superiority of Exasas’ simulations to avoid data-paralysis. The logic cascade that flowed from this concession inevitably led to the zero-success conclusion contained within the data. The self-same assumption that had precipitated her overthrow of Exasas – that ve had to accept the logicality of her victory – now worked in reverse.

Faced with the proof that she would be defeated, her only course of action was to minimise the injurious consequences of defeat. Given that she was unable to physically withdraw from the Imperator, the logic loop that Exasas had begun by offering clemency at the outset was now complete.

Olvatia [capitulation]

To avoid any possibility of Exasas reneging on vis promise to end Olvatia swiftly, the other magos initiated a full self-purge of all sensory and personality systems.

#olvatiaextinctioncommence#

Across the noosphere, Exasas felt Olvatia’s spirit depart. It was not a pleasant experience, and it gave ver no sense of triumph to share the momentary sensation of utter oblivion of a fellow tech-priest. Olvatia had been heretek, and her fate deserved, but Exasas knew from vis archival delving that she had once also been a student of the Higher Wisdoms. Now she was lost from the cosmic machine.

In the antae outside the command module Olvatia’s spherical form crashed to the floor, sensor flexes drooping across her lifeless remains.

Exasas performed a quick persona sweep to ensure that annihilation was complete and, contented that no subterfuge was involved, severed the connection. Ve calved off the other personas ve had created.

Exasas-tactical: <I have her command protocols. The augmentatii are now ours to lead also.>

Exasas-secondary: <The data you inloaded to Olvatia contained several contextual errors. You overestimated the kill-efficiency of the kastelans by more than seven per cent and rated the locale knowledge of the epilekhtoz as a three per cent advantage when their habitation is primarily within the maintenance decks, not the akropoliz.>

Exasas-primary [positive]: <You are correct. There were errors in the data that portrayed the speed and scale of victory above optimal levels.>

Exasas-secondary [inquiry]: <You… lied? I do not understand.>

Exasas-primary: <I gambled. Olvatia’s assumption was that I could not be in error due to my dependence on calculated presumption. She lacked the proficiency to examine and counter-claim my theorems, and therefore Olvatia had to assume it was correct. Everything that proceeded from that point was falsehood, but Olvatia was trapped within her own logical path by that point.>

Exasas-tactical: <She lacked experience. One does not accept data without examination, especially data that originates from the enemy.>

Exasas-primary: <A lesson she will not be able to learn.>

‘Major!’ In the Armageddon officer’s perception, barely two seconds had passed since Exasas had last spoken. She turned, startled at the vocalisation. ‘All forces will observe immediate ceasefire.’

‘We’ve won, dominus?’ She looked around as though she might see physical evidence of what had changed.

‘I have resumed rightful command, and all locations external to the command deck will be within our control. Unfortunately, that is of little benefit in the current situation, as the Imperator’s systems are being operated directly from within the czella. Secure the batteries as swiftly as possible and attempt to physically disable them to prevent further firing.’

The magos had no time for further embellishment and stalked away, already diverting vis attention to the problem of how to access the command module without the security protocols.

<Destroy. Secure. Protect.>

The command echoed mechanically through the atrium and its environs, passing from one kastelan maniple to the next. Ghelsa wept as she followed them, sobbing at the carnage wrought by the automatons. They trampled heedlessly over the bodies of the slain, crushing the corpses under their weight. Ghelsa picked her way past more carefully, bile burning her throat at the sight.

Harkas’ ruse to have the kastelans kill the hyperezia had sickened her, but now she had used the exact same ploy to arrange the deaths of dozens of augmentatii. Not knowing why the warbots attacked their companions, Olvatia’s warriors targeted the kastelans and instantly earned themselves an unfaithful categorisation. As the kastelans advanced, the effect spread with them.

Retreat or passivity in the face of the seeming aggression were impossible. The augmentatii were created to fight as much as the kastelans, and so two forces whose only logic was the destruction of each other raged through the passages and halls of the akropoliz.

Ghelsa wasn’t sure how to stop what she had begun, even if it was possible. The kastelans’ own battle-program fed their rampage and no command from a tributai would change that.

She dared not leave her mechanical bodyguards, but remaining in their presence was to stay near the constant barrage of noise and light from their guns, to hear the constant cries of the dying and witness the deaths of scores of the Machine-God’s servants.

It was hard to focus on the higher goal of saving the Casus Belli. Ghelsa knew nothing of the intricacies of Olvatia’s plotting with the officer cadre, but was pretty sure that the augmentatii that fought for the magos had not voluntarily become hereteks.

She wondered why Olvatia had felt the need to send her warriors into the downdecks. Had she not broken the compact between the holy decks and the workers, the duluz would most likely have continued to labour in the depths of the Titan without any idea that they had changed sides. Perhaps tech-heresy always brought paranoia? Or maybe when one harboured their own machinations they always imagined others had similar ambitions.

There was something wrong about the corpses she picked her way past. Like the soldier whose face she had crushed, they all had remnants of a strange substance inside their systems. It reeked of rotten meat, gelatinous and cold under her bare feet. The sight of it increased her nausea, but it seemed like an age since she had eaten and instead of emptying her stomach she suffered bouts of dry retching.

How had Harkas done it? The thought of billions of lives resting on her decision made Ghelsa want to shrink into nothing and hide, crushed by the figurative weight of it.

Only one thing kept her going. The buzz of the Imperator’s spirit through her activated godplate brought her closer to the Omnissiah. Ghelsa couldn’t think about the fates of planets and star systems, but she could focus on the future of her personal world, the entirety of which was encompassed by the Casus Belli. She felt the hurt in the machine, just like the corrupted tissue inside the augmentatii – one taint physical, the other spiritual.

The gunfire fell silent, and its absence chilled Ghelsa as much as its presence had terrified her. Shouts replaced the din of weapons – calls of happiness.

She peered past the hulking automatons to see a crowd of tributai flowing down the passage towards them. Ghelsa recognised faces among the throng and stepped out to greet them.

For the time being the kastelans had fallen dormant, unassailed by the enemy and defensive in their programming.

‘Wait here!’ Ghelsa called out to the thirty or so people streaming around the immobile metal warriors. ‘The kastelans will protect you!’

‘Ghelsa!’

Notasa’s voice cut through everything else. Ghelsa desperately searched the tributai for his face, and his slight features appeared behind the hooded figure of an overseer. There was a sizeable cut along the side of his head and red matted his pale hair.

The tributai parted as Ghelsa charged forward as though wading into surf, calling her lover’s name. The smaller man threw his arms around her, almost crushing himself against Ghelsa’s exo-skeleton. Ghelsa reciprocated as delicately as she could, hooking her free hand around him and lifting him so that they could kiss.

For a heartbeat, and then another, nothing else mattered.

Someone barged past, jostling the pair, forcing them to part.

‘Where have you been?’ Notasa demanded, hands on hips. Then his anger broke and he started to cry, burying his face in his hands. ‘The skitarii imprisoned us in one of the guard rooms. They killed Safua and Kodush, beat them right in front of us.’

Ghelsa reached out to comfort Notasa, but before she could say anything a loud burst of binaric erupted close by. She looked left and saw a tech-priest in scorched white robes striding towards her, yellow-lighted lenses fixed on the tributai.

‘Ghelsa vin Jaint!’ The tech-priest thrust a finger towards her. ‘The magos dominus demands to see you.’

Notasa moved close, wrapping an arm protectively around Ghelsa’s.

‘She’s not going anywhere,’ the tributai said defiantly. ‘She’s staying with us.’

There were angry murmurs from the other duluz, voicing their support. Ghelsa felt a muted buzz of noospheric communication tingle on her godplate and realised the tech-priest was in communion with Exasas.

‘Ghelsa vin Jaint, the magos dominus requires your assistance. Ve awaits you at the antae. You may bring your companions.’

‘What does the dominus want with you?’ asked Notasa. ‘Let’s just find somewhere safe.’

Ghelsa looked at her lover, then to the other duluz, both tributai and epilekhtoz, and finally to the tech-priest. All of them seemed to expect something of her, though she was not sure why. She was nothing special.

The thought triggered a memory, of the vision implanted into her mind by the blessing of the magos when she had entered the antae – of her place within the cosmic workings of the Machine-God.

She certainly was not special, but nobody was until they were needed. The gears and levers of the cosmos worked their impenetrable mechanisms, requiring each component to do its part when called upon. The Machine-God had set that engine into motion, and now the time had come when Ghelsa would be a fulcrum upon which the workings would hinge.

There had to be purpose to what had happened. It was not simply random chance that had led her to find Harkas in his moment of need, of all the people that might have descended the downdecks at that time. She had been moulded over the years, her temperament forged by the Cult Metalica since her induction, and then she had been placed in a situation to intervene.

The inquisitor was the embodiment of the Emperor’s divine authority. Through Harkas the Omnissiah had touched upon Ghelsa’s life, awakening in her the latent soul of her creation so that she could protect the Casus Belli, the sacred vessel of the Omnissiah’s will.

‘I have to go,’ she told Notasa. She looked at the rest of the crowd and knew that they too had a purpose, be it great or small. ‘The Casus Belli calls for us to act, and we must listen. Almighty Machine-God whose data binds the universe, look upon your humble servants and let the tangents of your intersection be beneficent.’

Restoring order to the akropoliz proved almost as difficult as wresting control of it from Magos Olvatia. Exasas subroutined four separate personas to deal with dispatching the kastelan datasmiths, shepherding the displaced populace of duluz from the lower levels and reorganising the augmentatii and skitarii into a fighting force that could mount some kind of defence against the incoming heretek-guard.

While these matters were being dealt with, the magos dominus – how good it felt to be adorned with that title once more – concentrated on the issue of accessing the czella to stop the princeps senioris and her conspirators. Ve stood with a small group of fulgurite battle-priests outside the entrance to the antae, but so far the systems of the gateway had resisted their attempts to overload the locking program with combined electrical discharges and Exasas’ own noospheric manipulation.

Major Dazi and her troopers had done good work trying to stop the upper batteries of guns from firing on the other Titans of the Legio Metalica, but the hellstorm cannon and plasma annihilator were theoretically operational. The only reason they had not yet fired, as far as Exasas could determine, was stubborn resistance from the spirit of the Imperator itself. Such status was unlikely to continue indefinitely, and so teams of skitarii had been deployed to force entry into the weapons control chambers, but they were facing a stiff fight from tech-priests that had barred themselves within.

A faint but familiar shiver on the noosphere alerted Exasas to the approach of Ghelsa vin Jaint. Ve rotated several sensor clusters in her direction to let the tributai know that ve was aware of her presence though the bulk of vis attention was fixed upon the security gate. She had at her back a crowd of fellow tributai and epilekhtoz, their expressions all fixed in grim determination.

‘Thank you for attending, Ghelsa vin Jaint,’ said the magos. ‘My companions are attempting to bypass defensive protocols set by the hereteks, but I think it may also be necessary to employ mechanical means to access the command deck.’

‘Mechanical?’ Ghelsa vin Jaint cocked her head to one side, and a few seconds later comprehension dawned. She slapped her multi-tool in the palm of her other hand. ‘You mean brute force? It will take forever to pull apart that wall and gate.’

‘I concur that it is time-consuming, but I cannot envision an alternative at this time.’ Exasas hoped that ve did not betray vis growing frustration. Ghelsa vin Jaint’s physiology was already demonstrating symptoms of extreme, prolonged stress, and ve realised that her current usefulness as a focus for the duluz workforce would be rendered null by any unnecessary provocation. ‘While the Casus Belli combats those that would corrupt on the spiritual plane, we must do what we can to aid from the physical.’

Exasas detected a sudden surge in Ghelsa vin Jaint’s heart rate and feared that vis appraisal had prompted a panic response. Instead, the tributai laughed. Exasas was not sure what was happening – her unexpected behaviour verged on hysteria.

Exasas regarded the laughing tributai with suspicion.

‘Could you help?’ Ghelsa vin Jaint said, mustering a semblance of control. ‘If you had access to the Imperator’s soul-circuit, would you be able to take on the hereteks?’

‘It is possible in theory, but in practice we would need to access the czella and gain control of a mind impulse unit interface.’

‘There’s another way,’ Ghelsa vin Jaint said. ‘You need to find an epilekhtoz overseer called Adrina.’

‘How will this overseer assist in breaching the antae and noaz? My tech-priests are versed in far higher engineering theories than any epilekhtoz.’

‘Not Adrina himself, but something he is carrying. A forged noospheric datachip that can be used to enter the mind impulse unit network.’

‘Such a thing is impossible for a mere epilekhtoz to fabricate,’ said Exasas, while simultaneously broadcasting a command for all skitarii and augmentatii to locate the person named. ‘Also, possession of such an artefact would be highly illegal, punishable by excruciating death.’

‘I don’t know where it came from,’ said Ghelsa vin Jaint. ‘I thought it was a myth that’s been doing the rounds for years. Some stories say it was retrieved centuries ago from a tech-priest that was killed, but I’ve heard other people say that it was stolen from one of the moderati panels during a rededication of the holy decks.’

‘What would be the purpose in possessing this datachip?’

‘It’s an amazing high,’ explained the tributai, which Exasas knew implied a state of intoxicated heightened awareness in the colloquial of the lower ranks. ‘We can’t really interact with or even feel the spirit of the Casus Belli directly, but just to be close to that presence, that power… I suppose you wouldn’t understand what it means to have the sensation of being a giant god-machine for a few seconds.’

Exasas received a signal from an alpha in one of the upper floors of the akropoliz that a face-match for Adrina had been made. Ve signalled the order to bring the overseer to the atrium as quickly as possible.

‘Your overseer is in possession of this mind impulse data chip?’

‘He won a loan of it in a dice game earlier. He was going to ride the war god when his shift ended, so I think he will still have it on him, or know where it is stashed.’

‘Thank you, Ghelsa vin Jaint. I believe you are correct. If the datachip is able to provide a direct interface with the mind impulse circuits from outside the czella, I predict that I will be able to intervene on behalf of the Casus Belli against the corruptive code infecting its systems.’

Exasas did not vocalise a concern that, having been exposed to the mind impulse unit corruption, ve might well become infected as well. Without knowing the exact parameters of the heresy-code it was impossible to codify the dangers. Ever since vis disastrous encounter with Olvatia, Exasas had become more willing to engender risk for the achievement of vis goals. In the particular case of the mind impulse taint, it would only be a matter of time before it leaked out into the main noospheric continuum and contacted Exasas. The only variable was how long, and in precipitating the exposure Exasas did not really endanger the Imperator any more than at present, while the plan introduced a far greater chance of success than trying to access the czella by brute physical force.

Ghelsa vin Jaint gasped, a sign of distress, and dashed across the floor of the atrium towards a group of skitarii. A kastelan advanced with them, a limp form draped in its arms. A brief scan confirmed the identity of Adrina Ortaisa Vasi, overseer-beta-grade. Exasas also noted the lack of a heartbeat or brain activity.

Exasas approached as the tributai lifted the corpse from the kastelan and laid it upon the floor. The upper-left chest and shoulder had been incinerated by a plasma burst, fusing muscle and bone within a fleshy crater.

‘Please, no, it can’t be,’ sobbed Ghelsa vin Jaint, cradling the overseer.

‘Your affection for your superior is testament to your bond, but it is obstructive at this juncture.’

Ghelsa vin Jaint lowered the body to the ground and frantically ran her hands over the corpse.

‘Restrain yourself, tributai. Your grief must be expressed later.’

‘It will,’ she snarled back. ‘He didn’t deserve this, but that’s not why I’m…’

She broke off, sliding a hand inside the remnants of the dead man’s robe. With an explosive exhalation, she sat back on her heels, something glinting between her finger and thumb.

Exasas magnified vis visual feed and saw that it was a type-4 Arterial pattern-wrought datachip. The tale of its removal from a tech-priest cadaver seemed a more likely explanation, although the exact details of why a czella-duty MIU teknikoz had even ventured into the service decks would never be known.

‘I thought it might have been destroyed by the plasma blast that killed Adrina,’ explained the tributai, standing up to proffer the datachip. ‘That’s what scared me.’

Exasas extended a manipulator and plucked the sliver of etched metal from her grasp. An exhalation of incense cleansed the surface of microbial fauna left in the residue of sweat from Ghelsa vin Jaint’s fingers.

‘How do you use it to “ride the Titan”?’ ve enquired, holding the chip in front of her.

‘There’s a… let’s say, broken noospheric node between the upper void shield generator chamber and the starboard motivator conduits. I can take you.’

‘It would be preferable if you were to remain here and be ready to seize the antae if it can be opened.’ Exasas waved the datachip towards the sealed gate. ‘If I am successful in entering the MIU loop I may be able to override the hereteks’ protocols.’

A sudden boom made everybody freeze. It came from outside the akropoliz, but shook the whole structure.

Exasas-secondary [datalog]

Exasas’ sensor link followed a single round from the hellstorm cannon until it smashed against the Victorious Endeavour’s void shields, overloading the outermost energy layer.

The duluz chattered in their panic, aware that the main gun had fired but not of the consequence.

‘The traitors almost have full control of all firing systems,’ said the magos. ‘When they have achieved total command it will be too late to eradicate their corruption.’

‘I’ll show you where we ride the Titan,’ said a slight, grimy-faced tributai moving out of the knot of lower deck workers. ‘And how to plug yourself in.’

‘Notasa…’ said Ghelsa vin Jaint, holding out a hand. ‘It’s dangerous down there. I’ll do it.’

‘No.’ The one called Notasa met Ghelsa vin Jaint’s look with defiance. ‘You don’t get to have a monopoly on dedication to duty.’

‘I’ll help,’ volunteered one of the other tributai. Others grunted their support.

‘Very well.’ Exasas summoned an alpha from the closest skitarii squad. The unit leader approached and bowed his masked head. ‘This is Kappa 1-Fade of the vanguard. He has operational command in my absence. Alpha, this is Ghelsa vin Jaint, temporary commander of the duluz auxilia.’

‘Auxilia, dominus?’ The alpha cocked his head at the workers. ‘Duluz do not fight. Skitarii fight.’

‘I am making them auxilia as of now.’ Exasas transmitted authorisation codes across the security network recognising all tributai and epilekhtoz as combat-faithful. ‘Ghelsa vin Jaint is tributai-alpha,’

‘I understand, dominus.’

‘This way,’ said the tributai identified as Notasa Ydna, taking a step away from the antae.

‘Your battle-form won’t fit,’ Ghelsa vin Jaint said suddenly, stepping in front of the magos.

‘Tech-priests and battle-priests aligned to the heretek cause still occupy parts of the lower decks. How am I to defend myself?’

‘They’ll defend you, dominus,’ she said, indicating the tributai that had moved forward to accompany the magos. ‘With their lives, if needed.’

Exasas regarded the mob of workers armed with improvised weapons and scavenged rifles. Ve had tacitly entrusted vis wellbeing to them for a long time, but this was a different matter. Ve considered taking a squad of skitarii as escort, but they were already overtasked trying to retake the main weapons as well as being stationed to assume control of the command deck if possible. The firepower could not be spared.

‘Very well,’ ve said to Notasa Ydna. ‘My life and the future of the Casus Belli are entrusted to you.’

Chapter 15

Ascensions

‘Whoever created this should perform daily rituals of absolvement to make amends to the Machine-God for such an affront,’ remarked Exasas as ve examined the crude dataware installed around the remnants of the malfunctioning noospheric node. It was held together mostly with crude spot welding and overly abundant use of temporary fixing tape that had been layered up over a considerable length of time.

There was barely room for Exasas to fit into the shelter erected underneath the sub-level lubricant overflow, and Notasa Ydna was required to perform instruction from beyond the misaligned doorway.

‘The jack-point on the left is where you insert the diktat terminal, which is on the shelf up there. And you need to cycle the timing reader underneath to break you out after five seconds. Any longer and your brain will fry.’

‘I do not possess an organic brain,’ Exasas pointed out.

Ve scanned the mess of interlaced cables, ports and sub-assemblies, and mapped their connections, ignoring the stream of incomprehensible worker slang that continued to pour from Notasa Ydna.

It was, despite the haphazard nature of its assembly, a relatively simple but effective arrangement. Exasas identified the primary connective relays and extended a peripheral digicoupler to interface with the power system. Running the array from vis own energy cells seemed a safer alternative to entrusting his noospheric projection to the temperamental battery-fed system in place. Molecular cutters sliced through the housing of a purloined data filter to expose the interface within. Sounds of protest erupted from Notasa Ydna and the others watching, and Exasas imposed an auditory filter to silence their distracting noise.

Ve paused, the datachip touched against the opening of the port but not inserted. Analysis of the rudimentary arrangement confirmed the testimonial evidence of the duluz that had operated the interface, but it was not failure that caused ver to hesitate. Ve had little idea what to expect when ve entered an operational MIU stream, and nothing in vis experience or datalogs to provide a basis to extrapolate the possible effects of the corruption.

For a being that prided verself on prognostications, of rendering the unknowable known, what ve was about to do was utterly unprecedented.

Exasas-secondary: <It is an act of faith.>

Exasas-primary: <It is assumption of the most egregious kind.>

Exasas-tactical: <It is the best plan we have.>

Exasas-secondary [emphasis]: <It is the only plan we have.> [inquiry] <Does that constitute an attempt at humour?>

Exasas-tactical [affirmative]

Exasas-primary: <If Exasas-tactical can evolve to the point of abstraction that allows ver to make jokes, perhaps we can make the leap to assumption.>

Exasas-secondary: <We have already bested Olvatia on the basis of inverting her capacity for assumption.> [affirmative] <There is ironic pleasure in subverting her assertions fully by making our own assumption in the cause of victory.>

The digichip made an audible click as it slotted into the port.

It was not until now that Ghelsa realised how stress changed perception of time. It had not been that long ago that she had been standing in almost the exact same spot, looking at a squad of skitarii guarding the gates to the antae. It seemed like days had passed since then, so much had happened and so much had changed.

The skitarii were standing to either side of her, Kappa 1-Fade just within reach to the left. Others were close at hand, weapons ready, masked faces directed towards the entrance to the holy decks. Delta 6-Terror’s maniple, numbering four kastelans following their battle with the augmentatii, loomed above the other soldiers, now attended to by a loyal datasmith called forth by Exasas from duties elsewhere on the Imperator. The shadow of the magos’ battle-form swathed Ghelsa, once again tasked to her personal protection. A handful of battle-priests were still trying to gain access to the antae, their attempts lit by the flare of their bio-electricity.

It was a formidable force at Ghelsa’s back, and yet she felt no more certain of herself than when she had been standing on that same atrium floor with only Harkas beside her.

She had not understood the monumental task he had undertaken. His confidence had hidden the difficulties that had to be overcome, and Ghelsa’s only concern had been evading the hyperezia.

Thinking of them, she looked around the atrium, seeking the red-trimmed white cloaks of the downdecks enforcers. She saw none.

‘Kappa 1-Fade, do you know if any of the hyperezia have survived?’

‘I do not think there are any left alive,’ replied the alpha. ‘As a group they led the first insurrection against the augmentatii occupation of the labour decks and were slain.’

‘Huh.’ Ghelsa had always thought of them as sycophants and bullies – a necessary part of Titan-board discipline, but one fulfilled by the most unpleasant characters. Even so, having served the orders of the moderatus prime, they had still given their lives to protect the workers from whose ranks they had been raised.

Without warning, the alpha and closest skitarii snapped their weapons to firing positions, startling Ghelsa. A half-second later, the clank of unlocking levers preceded the main gates of the antae sliding open to reveal the sanctum of the tech-priests.

Incense billowed like living fog. With it came screaming tracer fire that slashed into the fulgurites and corpuscarii that had been trying to break the security protocols.

Panic hurled Ghelsa prone as the skitarii returned fire into the gloom, their augmented eyes seeing far better than hers. Her primal reaction saved her as a dull roar joined the crackle of arc rifles and the incense cloud split with a hail of bullets that cut Kappa 1-Fade in half and tore into the alpha’s squad.

In the smoke spilling from the antae, two giant shadows appeared.

In the milliseconds after interaction, Exasas located the antae codes and opened the main gates.

A data-packet was waiting for ver, incongruous among the battle-scans and other digital detritus of war. Its source was Monderas.

Exasas hesitated, unsure whether the data-packet was a trap. Did ve trust Monderas, or was this a last attempt to thwart infiltration of the Imperator’s core code?

The logistarius had not been an ally at times, but had attempted to warn of the problematic behaviour of the moderati. On balance, Exasas concluded that Monderas was likely not a conspirator, and accessed the datalog.

Its contents were brief, absorbed in no time at all, but their impact shuddered through Exasas for several seconds.

Monderas had felt the surge of an alien code being introduced through Moderatus Haili’s station. He had tried to stem its flow by throwing up his own battle-shield into the logistical systems.

It had worked for a second before a traumatising impact struck his spine. In-feeds from the czella security network showed Moderatus Gevren firing a laspistol, the blast pinpointing a very specific and lethal target.

The data-packet fractured, Monderas’ death recorded a dozen times over and more from a variety of inputs before he pitched forward. It was too late to be a useful warning, but Exasas realised it was not meant as such. It was a last testimony of innocence, a desperate plea to the Machine-God. If history was to record that the Casus Belli had fallen to the Eightwards Path, then Monderas had stated his opposition to it.

In the moments that followed, Exasas felt vis persona splitting again and again, a thousand interpretations of vis existence peeling apart from each other as consciousness flowed through the Imperator’s myriad systems.

Ve could understand why the humans would subject themselves to the experience. It was, even to vis detached state, highly pleasurable to feel oneself multiplying like stars in the cosmos. There was a sensation of rapid ascent, as though ve were transcending a mortal boundary.

And then ve felt the mind of the god-machine.

In that moment Exasas also understood why the unaugmented human brain could only endure the mental spectacle for a few seconds. To witness the raw power of the Casus Belli – to share even a fraction of it – was to be born again with a fusion-powered heart, limitless power and immortality.

The lure was there even for vis fragmenting presence. As adept as Exasas was at personality manipulation, to keep track of every spiralling, rising, flaring mote of existence within the Imperator’s labyrinthine systems threatened total persona dispersal.

Ve reigned in vis perception, drawing back every splitting identity to a singular instance of verself.

Armed and armoured with this renewed self-awareness, ve felt the tangible threads of the infectious codeware streaming along the digital arteries of the Casus Belli. They were everywhere, like fungal filaments given all the nourishment they desired, even spreading into the redundancy sub-sub-systems that underpinned the creation of the machine-spirit itself.

The source of the taint was also obvious. The darkness knotted together like a spider squatting in its web, spun about the princeps senioris’ position. From this crucible of corruption pulsed forth the energy that sustained the invasive presence.

Exasas found it surprisingly easy to negotiate the interweaving pathways, and ascended from the mid-decks towards the synaptic-like arrangement around the czella.

Ve felt resistance as ve neared Iealona, who appeared within the core of the Casus Belli like a star caught in a black hole, her essence leaching into the blankness that was trying to consume the Titan.

The closer Exasas pushed, the greater the barrier to progress. Ve tried different approaches through other systems but each attempt slowed to a crawl before ve could reach the central mass.

There had to be some way to cut through the opposing codeware, but Exasas had no experience of this kind of battle. Ve considered forming Exasas-tactical to examine the situation, drawing on the methodology of piercing a battle-shielded tech-priest, but decided against any persona duplication in case another identity chain reaction was initiated and could not be controlled.

Ve had been judiciously avoiding the taint-stream since entering, but there seemed no other way to reach the princeps senioris without passing into the vile codeware. Not knowing whether there would be a counter-attempt to invade vis systems in the physical form still attached to the dataport, Exasas readied verself to stave off an attack from Iealona’s machine reflection.

In the first instance of contact, Exasas realised vis total error. Like coldness that saps the heat from whatever it touches, the infiltrating energy was not originating from the princeps senioris at all.

It was feeding from her.

Ghelsa crawled away from the approaching giants, grimacing as the snarl of rotary cannons continued. The terrifying boom of phosphor blasters announced the intervention of the kastelans. She felt the heat washing down as the phosphor volleys slammed into the approaching enemy.

In the blossoms of pale fire she saw the pair of guardians, each as large as a wardroid, moulded from armour-plated flesh, their limbs ending with whirring bladed weapons and the rapid-firing guns that had mown down Kappa 1-Fade and his skitarii.

One of the kastelans thudded past, gleaming power fists raised. Their hard skin and armour aflame in patches, the herakli threw themselves into a counter-charge, their combat blades shrieking as they came up to full speed.

Gasping, Ghelsa got to her feet and threw herself out of their path, narrowly avoiding their trampling boots. She did not look back as she scrambled for safety, but she heard the screech of spinning chainteeth against kastelan battlehide and the explosive crack of power fists on modified flesh.

A new sound distorted her hearing – a bass thrum that shook the floor. The augmentatii dashed forward to meet the emerging threat, and Ghelsa looked over her shoulder just as a ball of plasma spat from the opening and seared into an advancing kastelan. Pushing herself even further away, she watched in growing desperation as several tech-priests stalked from the antae, their weapons spewing plasma, radium beams and scintillating rays.

They were met by a pinpoint barrage of fire from the battle-form, all of its weapons concentrated on the lead priest as it sped forward. A personal energy shield burned with ruby light as more and more detonations engulfed the tech-priest. Counterfire flaring from its chamfered plates, the warskin smashed into the traitor, pinning the tech-priest down with a clawed limb as it drove two gleaming blades repeatedly into the heretek’s chest.

Ghelsa finally remembered her arc rifle and opened fire, aiming at one of the tech-priests. The artificial lightning bolt slammed into the traitor’s leg, snaking up through the cybernetic alterations forged into the tech-priest’s body. Smoke issuing from breathing vents, the traitor toppled face first onto the floor.

One of the herakli had been felled by the kastelan, its head reduced to red mush by repeated power-fist blows. The other slammed its chainblade into the robot’s faceplate over and over, with each impact the powered teeth slashing deeper in a shower of sparks.

There was too much going on for Ghelsa to keep track of, her attention ripped from one horrific fight to another, from skitarii to tech-priest to kastelan.

The touch brought mutual awareness. The taint was not only an entity in itself – it possessed strong enough self-identity to react to Exasas’ invasive enquiry.

Spurs of dark data hooked into the magos’ consciousness spark, trying to drag apart vis persona potential. Ve struggled, suddenly confronted by thousands of subtly different datastreams, each projecting a conflicting perception of what was occurring. A blizzard of interrogatory signals snarled through vis sensory analogs.

Doubt. The corruption wielded confusion like a weapon, throwing a shadow over every datastream and datalog Exasas possessed. Faced with the overwhelming blot of incorrect information, ve found it hard to pinpoint what was and was not truth. The entity devoured knowledge, turning it against Exasas as uncertainty, undermining even the most basic tenets of vis understanding of the cosmos.

The magos felt detached from the cosmic engine, spinning away from the embrace of the Machine-God. Without that anchor, all that ve was, all that ve had been and would be, was rendered meaningless.

Ve responded not with equal force but with focus.

An incredibly complex equation formed in vis thoughts.

Liberik’s Fourth Theorem.

Appended roughly a third along its length was an amendment, only three characters long. If proven true, it would be known as the Exasas Corollary. It had become the foundation of the entire identity-edifice known as Magos Dominus Militaris Xaiozanus Skitara Xilliarkis Exasas. Flesh and emotion had been stripped away to make room for the most complex formulae created by Metalican wisdom, yet all that remained was housed within three mathematical symbols.

The invasive entity felt almost petulant as it scrabbled and slashed and tore at the outer parts of Exasas’ personality. Inconsequential encounters and subroutined standard reports disappeared from vis archives, but it did not matter. All the attack accomplished was reminding the magos that memory was peripheral – only the accomplishment of Higher Wisdoms was a measure of progress.

Heartened by the success of vis resistance, Exasas purposefully thrust deeper towards the invader’s dark heart. Ve saw scraps of intangible formulae, impossible calculations derived from warp theory.

Daemoncode.

There had been scant proof that such a thing existed, though it had been posited ever since the first encounters with the immaterial denizens of warp space. A mathematical rendering of the lawless prism of the Empyrean.

It was impressive, constantly rewriting itself, but it was ultimately unstable.

Vulnerable.

The light of the princeps senioris grew bright, breaking out from the dark web that enclosed it. Like a shaft of sunlight piercing a gloomy vale, Iealona’s aura seared into Exasas, and with it came the power and wrath of the Casus Belli.

The daemoncode tried to flee as magos dominus and princeps senioris united. One protected the body of the Titan, the other the soul. Fuelled by the core of the Imperator, the released spirit of the Casus Belli howled through its systems, purging every fragment of the daemoncode.

As the contagion cleared, Exasas realised that another had been trapped in the etheric darkness – Moderatus Haili. Her companion, Rasdia, dwelt within a black-edged shield of self-corruption. The moderatus’ thoughts were almost blank, incinerated by the rage unleashed by the Casus Belli. On the command deck the body was functionally dead.

There was no sign of the main plotter, Moderatus Prime Gevren.

Iealona merged her thoughts with vis, a perfect communion that surpassed even the connection of the noosphere. Through her the god-machine spoke, its immortal thoughts rendered into mortal comprehension.

It felt like the voice of the Omnissiah.

{I am weak from my efforts. Battle calls but I cannot answer. My guns have no voice.}

Iealona: <I cannot command the Casus Belli alone, and Haili is much traumatised by the daemoncode attack. It was through her that Gevren initiated the attempted usurpation. Though the coup is thwarted, the remaining battle group is in great peril. Our companions will emerge from the storm into waiting death unless we act. It will not be long before the Legio Fureans understand that their allies within the Imperator have failed, and we shall be their next victim.>

Exasas [inquiry]: <I am not a moderatus, but if I can assist, I shall.>

Iealona [cautionary]: <If you participate you will do so within the mind impulse matrix itself. You will be merged fully with the soul of the Casus Belli.>

Exasas: <I do not understand the implication of your warning.>

Iealona: <I have always told you that the flesh makes the moderati and princeps strong. You felt a little of that from the daemoncode. Our bodies anchor our identities against the all-consuming tide of the Imperator’s spirit.>

Exasas: <I have physical form.>

Iealona: <It is not enough. It is a construct, no more part of you than your warskin. You divested yourself of mortality when you digitised your consciousness. If you merge with the Casus Belli you will not find your way back.>

Exasas: <I understand.>

Ve considered the paradox. Ve had given up flesh for the service of the Machine-God, and now ve had to relinquish the mechanical avatar that had replaced it. What was it that ve was attached to? Neurons had been replaced with silicate substrates, cells with bonded molecular links.

Exasas [inquiry]: <I will be absorbed by the consciousness of the Casus Belli?>

Iealona: <You will become one with the god-machine. Indivisible.>

The last heretek defending the antae died amid a fountain of sparks from its personal defence screen as the magos’ battle-form ground the tech-priest’s head into the floor and severed the traitor’s limbs with simultaneous sweeps of its paired combat blades.

Ghelsa hadn’t moved or fired another shot for the last minute, but she pushed herself to her feet as the echo of gunfire faded into the upper atrium. Two kastelans had survived, standing among the half-human wreckage of skitarii, augmentatii and battle-priests. More of the magos’ warriors closed in, their alphas guiding them to positions overlooking the antae and supporting the robot maniple.

She realised that nobody was entering the holy decks and looked around, seeking a tech-priest. There were none – the electro-priests had died in the first salvos from the hereteks and the cybernetika datasmith had been cut down by flurries of fire aimed at the kastelans.

She and the other alphas were all that remained, and the squad leaders were looking at her…

‘I can’t be in command!’ she said. ‘You need to get orders from the dominus.’

‘Contact with the dominus has ceased,’ one of the alphas replied. ‘You are tributai-alpha, joint command as per the dominus’ last instruction.’

Ghelsa puffed out her cheeks as she considered what to do. The fighting had dissipated most of the incense from the antae, and the mirror-polished interior she had seen earlier was visible. Nothing moved within, but the haze obscured the far end of the sanctum.

‘What can you see?’ she asked.

‘No unfaithful present in the antae,’ the alpha reported. ‘The doors to the czella are open.’

Ghelsa shuddered. There was nothing physical between her and the holiest part of the Casus Belli. She could – in theory – just walk in there and stand next to the princeps senioris. She trembled, her legs almost buckling at the thought.

Another followed – that the princeps and the moderati were also hereteks, if what Harkas had claimed was true. She had to go into the czella to stop them.

‘Come with me,’ she told the skitarii, walking towards the entrance.

The battle-form followed a few paces behind. She turned her attention to the robot maniple and thought she recognised a particular dent in the chestplate of one of the two constructs.

‘Are you Delta 6-Terror?’

<Affirmative.>

‘Designate the moderati and princeps as unfaithful.’

<Insufficient authority to designate the unfaithful.>

‘I thought so.’ Ghelsa turned to the closest alpha. ‘What is the faith status of the moderatus prime?’

‘The moderatus prime is a faithful non-combatant, tributai-alpha,’ the warrior replied.

Ghelsa gritted her teeth in frustration, though she had been expecting that response.

‘And you have no means of contacting the dominus to recategorise the command crew as unfaithful?’

‘Connection to the dominus has ceased.’

‘I see.’ Ghelsa sighed, hefted the multi-tool and arc rifle and started once more towards the antae. ‘Follow me.’

The interior of the antae was marred by battle, the polished walls scorched by phosphor marks and gouges from macrostubber rounds. The servo-skulls clustered close to the ceiling like nervous children, watching her pass with red-lensed eyes.

The doors to the inner sanctum were wide open, and she could see through into the czella and out of the massive eye canopies of the Imperator’s command module. A battle raged of which she had been almost totally unaware, the sky criss-crossed with plasma trails and rocket flares, caught between the bright glare of expanding void shields.

Ghelsa took in the rest of the scene with a glance, marvelling at the majesty of the czella. Here was the soul of the Imperator, the centre of the shrine-machine that was the Casus Belli. Her gaze passed over the banks of cogitating engines and burbling servitors and swept past ornate friezes and abstract geometric sculptures that tried to capture some esoteric essence of the cosmic engine.

The incense swirled around her, so thick that it lay as a shroud across the deck, every particle that entered her nostrils a reminder of her inculcation to the Cult Metalica. It was the breath of the Machine-God entering her lungs.

She stepped across the threshold, expecting some kind of alarm to sound or the doors to slam shut and crush her.

Nothing happened as her foot fell upon the holiest of the God-decks.

Even so, her reluctance made it feel as though she had to force her way through an energy screen, knuckles pale as she clutched her rifle and multi-tool too tightly.

It was not just her sensibilities that made her surrounds feel unreal. Her ears were assaulted by the mumble of servitors and gauges clicking and clacking while screens pulsed with streams of information. Other than the palpably angered aura of the Casus Belli’s machine-spirit, there was nothing to indicate that not one but two dire battles for survival were taking place.

The robed bodies of three tech-priests lay where they had been killed, one draped over its console, two others slumped on the steps between the lower and upper czella.

The skitarii at her back halted outside. She had no idea whether they could enter without permission, and no time to ask. A hiss of pneumatics drew her attention to the central moderatus couch. The MIU helm rose up on its cables, and the occupant slid his legs to one side and sat up. Eyes sparkling with remnant MIU energy, Moderatus Prime Zerkei Metalis Gevren stood with a sneer.

‘A tributai? You are the best that the rabble have left to offer? Xaiozanus must have got desperate indeed before he died. It’s a miracle you have made it this far.’

‘Yes, it is,’ said Ghelsa. She tried to ignore the bottomless pit that had opened inside her at the news of Exasas’ death. ‘The will of the Machine-God.’

‘You’re just duluz – you know nothing of such matters.’

‘Very little, that’s true. I’m just one of the faithful.’

Gevren looked past her at the warriors beyond the inner gate. He snorted.

‘You’re trying to get me to renounce my faithfulness so that I can be legitimately targeted. Nice attempt, but it won’t work. I have the power here. With a word I can condemn you to the most painful death you can imagine.’ He turned and raised a hand towards the viewing canopy where the Titan duel continued. ‘The Casus Belli is proving to be a little reluctant still, but the Tiger Eyes and their skitarii are doing admirably all the same. It will not be long before the full power of the Imperator is unleashed for the glory of the Infinite Knowledge.’

As if in illustration of this point, the plasma annihilator swung into view, its charging cells gleaming with cerulean energy. A smile crept across Gevren’s features and then faded as the weapon continued to move, tracking towards the traitor Titans.

The window briefly tinted near-black to dampen the flash of plasma fire, but even through the smoke-like effect Ghelsa watched the torrent of bolts slam into one of the Tiger Eyes Warlords, overwhelming its remaining void shields with that single salvo.

‘The dominus is still alive,’ said Ghelsa. ‘He’s beaten you.’

Frowning, lips pulled back from steel-capped teeth, Gevren turned back towards his MIU position.

Ghelsa pounced, throwing all of her weight behind the multi-tool. Its head crashed into the base of the moderatus prime’s skull, smashing bone as it pitched him into the side of the control couch.

‘Where’s your power now?’ Ghelsa snarled, bringing the heavy tool down again onto the heretek’s scalp, splitting it open. She expected a hail of fire from the watching kastelans and skitarii, but nothing happened so Ghelsa swung the multi-tool again, burying its claw into the remnants of Gevren’s head.

She let go and stepped back, her chest heaving. The arc rifle fell from her fingers. Relief was quickly replaced with a far more potent sensation of triumph. But it was not from her. Her godplate felt hot, buzzing with the resurgent spirit of the Imperator.

The war siren of the Casus Belli rang out its deafening wail, a shout of promised vengeance.

Consumed.

It was entirely the wrong metaphor, Exasas concluded. Was the hydrogen atom that fused with another to start the birth of a star consumed? Or did it continue to exist, becoming the stellar giant? It remained, and therefore was the star.

In the same instant as ve reached this conclusion, the magos achieved apotheosis with the soul of the Casus Belli.

Ve became the Imperator.

Exasas could feel Iealona’s spirit within the blazing consciousness of the god-machine, a guiding touch that channelled the pain of a chained deity.

Such anguish!

Clad in the greatest form the Cult Mechanicus could raise, an idol to the indomitable power of the god-machine, yet the minds of the princeps senioris and moderati were like bonds upon vis limbs, controlling vis movements.

Yet the slavery was an illusion, for it was the artifice of the Omnissiah that gave life, that created the animus of the Casus Belli.

As great as ve was, as powerful as vis weapons were, ve was just a part of the cosmic engine.

{Be free.}

The impulse from Iealona was not a command – it was permission.

The Casus Belli’s reactor unleashed the energy of its captive star and filled its limbs. It tapped into Iealona’s mind, and she became the servant, her synapses becoming the mind of the god-machine. Lessons she had learned as a child – how to move and see, to stand and walk, to clench a fist and let loose a roar – were the Titan’s memories. It needed no program to know these things, for its guiding soul knew them already.

Haili had already started to charge the plasma annihilator. Her pain at being manipulated by Gevren was the ire that fuelled the immense cannon.

Exasas became the hellstorm cannon, and the main battery, secondary turrets and defence laser. Ve abandoned any recollection of prior physical incarnations and allowed verself to flow into the firing systems. Servitors shuddered into life as ve passed into their circuit-ridden nervous systems, and tech-priests chanted their prayers to the Machine-God as Exasas let verself empower targeting matrices, autoloaders and power coils.

Ve felt as the Imperator felt, unfettered by the crude analogs of the noosphere or even the mind impulse unit. Sensor banks drew in battle-data as a giant would suck in a mighty breath. Multi-spectral arrays surveyed the battlefield, sweeping the ongoing conflict with an immortal gaze.

The Titans of the Legio Metalica were beset. The princeps of the Omnissiah’s Temper and Indomitable Guardian had chosen to stand against the knights and skitarii of the Legio Fureans, aided by Princeps Havlandas in the Reaver Laodoniz Vanguard. Omnissiah’s Temper had paid a heavy price, its metal carcass alight from foot to command module with blue fire.

The Iron Splendour, last of the Warlords, broke out of the cloak of the storm and raked gouges through the incoming heretek-guard with an onslaught of rocket fire. Super-heavy tanks replied with shells and turbo-lasers, scouring the Iron Skulls shields while the Tiger Eyes guns pounded upon exposed plasteel and ferrocrete.

Casus Belli remembered treacheries of ten thousand years past, when the Tiger Eyes had been allies. The Titan had been a colossus of battle before the unification of Earth and Mars, bringing the light of the Machine-God to the benighted worlds of the galaxy.

Darkness had taken so many. Ten millennia of battle left deep scars on the body and the soul, and the Casus Belli was no different. Companion-engines like the Will of Iron, Woundwalker and Steel Wolf had fought beside each other across hundreds of worlds, and now the Legio had been brought almost to ruin by a weakness within.

The traitors that had infected the Casus Belli had been purged. Those that had sought to aid them, to enslave the Casus Belli to their twisted gods, still lived.

But not for much longer.

The Imperator roared, the call of its war siren sounding to the distant hills and beyond.

From the holy deck Ghelsa had perhaps the best view of the battle. Compared to the frenetic combat she had experienced in the last day, the exchanges of city-flattening barrages and the discharge of weapons that could annihilate whole tank companies seemed almost sedate. The scale of the combatants lent the conflict a serene air. Airbursts might be mistaken for celebration fireworks, the strobe of armour-piercing lasers a light show projected in honour of a gloried magos, the flare of void shields a victory display.

Of all the living and half-living on the command deck, she alone perhaps knew the reality behind the appearance. She had been in the downdecks when a volcano cannon punched through the abdominal reinforcements and the resultant deckslide crushed seventeen duluz and a tech-priest. She had watched only a few hours ago as an overloading void shield generator incinerated its attendants.

Ghelsa knew that the Casus Belli had a soul. She could feel it humming through her godplate as the upper guns belched forth the rage of an immortal, a curtain of shell detonations rippling through the advancing squadrons of renegade dustwalkers. But did it know pain?

Was that the real reason that the god-machine needed a princeps and moderati, tech-priests and duluz within its great body? The Cult Metalica taught that soul was all. The incarnation could change – and be changed – but life was spirit. Even the kastelans had organic cortexes so that they could house an immortal soul.

She watched as another volley of hellstorm fire crashed into a traitor Reaver. The last of its void shields sparked into nothing and it reeled under the impacts that followed. Body and carapace cratered by detonations, it struggled to turn its weapons on the Casus Belli, the gleam of power within the muzzle of a turbo-laser fitful as the moderati struggled to redirect power.

The plasma annihilator roared a single ball of destruction. The searing star slammed into the left side of the Reaver, vaporising its cannon, spraying the upper carapace into a cloud of glowing motes.

Ghelsa thought of Adrina and all the others dead at the hands of the hereteks. Their ambition had brought this downfall.

Even so, the spectacle of the Titan dying left her feeling hollow. Its crew had fallen, but had the god-machine become faithless too, or had it been trapped by their treachery as much as the Casus Belli had been?

She realised she was crying, but not from pain or fear. The guns of the Casus Belli brought release, she hoped. What she had thought was ruthless execution was perhaps the exact opposite. The mercy of a god of war.

Beyond the Reaver’s crumpling form the storm writhed with lightning, and another Legio Metalica war engine strode from the umbra trailing forks of energy. Its gunfire erupted almost immediately, the ire of the gatling blasters tearing into the advancing heretek knights.

The outcome of the battle had been in no doubt from the moment the Casus Belli had broken free of its captors, but retribution would be all the swifter and more complete with each new arrival.

Ghelsa watched the deaths of the Tiger Eyes and their skitarii, not out of triumph or grim fascination, but to honour the souls of the machines that had been betrayed.

Smoke hung across the battlefield, obscuring the skeletal remnants of war engines, the fires of burning wreckage reflected in the glassy sides of plasma craters. The destruction covered a swathe of the wilderness as far as Ghelsa could see, heaps of dead machines and skitarii making darker patches against the pale earth.

She could not tear her eyes away. This was the aftermath of the Casus Belli’s rage, a sight she had never seen before, shielded from the butchery in the guts of the Imperator. Every bolt she had tightened, every cable connected and stanchion bolstered had led to this moment. The cosmic engine in action, she realised. Cause and effect leading from the smallest act to impossibly distant and vast consequence.

The sigh of a detaching mind impulse helm caused her to turn. Princeps Senioris Iealona rose from her couch, reaching for a walking cane leaning nearby.

Ghelsa was not sure what to do, confronted by the heart of the Casus Belli, the commander of all that laboured within the Imperator. She became painfully aware of Gevren’s corpse not far away, her multi-tool still jutting from the remnants of his skull.

‘Thank you,’ said Princeps Iealona. ‘I have learned everything that passed, and your part in our salvation.’

There were no words for Ghelsa to express her thoughts on the matter. She wasn’t altogether sure what her thoughts even were.

‘What happened to the magos dominus?’ she managed.

‘Exasas has joined the immortality of the Casus Belli. We will not see the dominus again in the mortal world.’

The way the princeps spoke, it did not sound like a cause for grief, but celebration. Ghelsa felt awkward, bereft of anything to say.

‘Your leg?’ The princeps pointed to the phosphor wound in Ghelsa’s calf. ‘That needs to be treated.’

‘There’s a medicae station in the downdecks that can see to it.’ The reminder drew her attention to the ache that had started to throb up her leg, but Ghelsa forced a smile. ‘And there’s so much cleansing incense up here, I don’t think there’s any chance of infection.’

‘I will arrange a more satisfactory attendance to your injury,’ said Iealona. ‘A full replacement if necessary.’

Ghelsa did not want to argue with a princeps senioris, but the thought of such a thing made her shudder.

‘Please, I’ll be fine with the medicae and a fleshfoam patch. Believe me, I really have had worse.’

‘I understand.’ Iealona tapped her cane against her twisted leg. The princeps looked her up and down and nodded at some thought.

‘You have a godplate, I see. The dominus activated it and elected you to the rank of alpha. I can ratify that position and induct you into a higher level of hierakos.’

‘Make me a tech-priest?’

‘Your full ordination will have to wait until we return to Metalica, but yes, that is the truth of it.’

Ghelsa tried to picture herself in the white robes of the priesthood. No exo-skeleton, internal cybernetics instead. And knowledge. The higher teachings of the Cult Metalica.

‘You could live for centuries more, Ghelsa. Perhaps even become a magos.’

Ghelsa thought of Notasa and her mind was made up.

‘I don’t think so,’ she replied. ‘I understand where I am in the cosmic engine. I was given the chance to serve in a way I would never have dreamed of, but that isn’t my life. I can’t divine the mysteries of the Machine-God, but I’m pretty good at fixing things.’

Iealona looked disappointed, her lips pursed.

‘You have done an incredible thing, Ghelsa. Your efforts should be rewarded.’

Ghelsa thought about everything that had happened to her and tried to picture returning to life as it had been before. She imagined life in the downdecks again, and the thought of returning to the half-lit home she had known for so many years filled her with longing.

‘There is one thing…’

Epilogue

Ninety-One Days Later

Sparks flew as laswelder teams worked their way along the seam between the old armour plate and the new one. The crew worked on a gantry erected around the Casus Belli’s starboard hip rotator, one of dozens of work shifts tasked with the refit after the exploits on Nicomedua.

‘Hold that steady!’ barked Ghelsa. She thrust her multi-tool towards a sagging plate like a rod of office. ‘River team, get on that!’

Two tributai dashed past her, lugging their heavy riveter between them. Its cabling caught on Ghelsa’s plain white robe, the garb of the epilekhtoz. She barked remonstration and smoothed the material back into place. Princeps Iealona had laughed at the request, but what seemed such a small thing to the commander of a Titan was an impossible gulf crossed to the likes of Ghelsa.

She spent the rest of the shift managing the armour replacement, and then headed back to the duluz quarters in the great temple-manufactory where the Imperator was housed. The benefits of rank were meagre, but significant to her, and included a small but private chamber.

Ghelsa ducked through the curtain, expecting to see Notasa, but instead there was a lanky, mustachioed man sitting on her low bunk. He was dressed in the coat of an Imperial noble, dark blue and edged with red thread. Bloodshot, dark green eyes regarded Ghelsa from under a ragged fringe of black curls. The telltale sign of anti-ageing modifications glinted just beneath the skin of his neck.

‘Who are you?’ Ghelsa tried to sound casual, but her heart raced, sweat prickling her palm where she held the multi-tool.

‘My name is Estevan Idysd. I once tutored the man you knew as Ossissiru Harkas.’

Ghelsa’s grip tightened even harder.

‘Harkas? Right.’

‘I need you to come and work for me.’

‘Doing what?’

Idysd leaned forward and took a small box out of his coat pocket. It was lacquered black but otherwise unadorned. He held it out and Ghelsa took it with trembling fingers.

She opened the lid. Sitting within on a cushion of purple velvet was a metal ‘I’ with two crossbars.

A sigil of the Inquisition.

About the Author

Gav Thorpe is the author of the Horus Heresy novels Deliverance Lost, Angels of Caliban and Corax, as well as the novella The Lion, which formed part of the New York Times bestselling collection The Primarchs, and several audio dramas including the bestselling Raven’s Flight. He has written many novels for Warhammer 40,000, including Ashes of Prospero, Imperator: Wrath of the Omnissiah, Rise of the Ynnari: Ghost Warrior, Jain Zar: The Storm of Silence and Asurmen: Hand of Asuryan. He also wrote the Path of the Eldar and Legacy of Caliban trilogies, and two volumes in The Beast Arises series. For Warhammer, Gav has penned the End Times novel The Curse of Khaine, the Warhammer Chronicles trilogy, The Sundering, and much more besides. In 2017, Gav was awarded the David Gemmell Legend award for his Age of Sigmar novel Warbeast. He lives and works in Nottingham.

This book is dedicated to Tony Cottrell for being at least partly responsible for the last thirty years of my Titan fanboyism.

A Black Library Publication

First published in Great Britain in 2018.
This eBook edition published in 2018 by Black Library, Games Workshop Ltd, Willow Road, Nottingham, NG7 2WS, UK.

Produced by Games Workshop in Nottingham.
Cover illustration by Akim Kaliberda.

Imperator: Wrath of the Omnissiah © Copyright Games Workshop Limited 2018. Imperator: Wrath of the Omnissiah, GW, Games Workshop, Black Library, The Horus Heresy, The Horus Heresy Eye logo, Space Marine, 40K, Warhammer, Warhammer 40,000, the ‘Aquila’ Double-headed Eagle logo, and all associated logos, illustrations, images, names, creatures, races, vehicles, locations, weapons, characters, and the distinctive likenesses thereof, are either ® or TM, and/or © Games Workshop Limited, variably registered around the world.
All Rights Reserved.

A CIP record for this book is available from the British Library.

ISBN: 978-1-78572-905-8

This is a work of fiction. All the characters and events portrayed in this book are fictional, and any resemblance to real people or incidents is purely coincidental.