Amongst the ruination of the ancient scriptorium, a statue of white marble was stirring. Slowly, tentatively, the figure came to life, shifting its position to better observe the courtyard on the other side of the broken balustrade. It moved with a practised silence, resting the nose of its bolt pistol on a fragment of the shattered stairwell, its jaw set firm with grim determination.

High above, through the canopy of shattered beams and broken roof tiles, birds wheeled in an empty sky, punctuated only by the distant heat trails of drop-pods bombarding the grassy savannahs to the east. The place was shrouded in an eerie cloak of stillness, as if the building itself was somehow holding its breath, waiting for something inevitable to happen.

Veteran Sergeant Grayvus of the Raven Guard peered around the debris with eyes of pure obsidian, his pale skin stark against the surrounding stonework. The alien was barely visible, even with his augmented senses. Only the occasional alteration in the quality of light or the ghost of movement betrayed its presence in the courtyard at all. He wasn't yet sure if the creature had noticed him, or whether it was toying with him, waiting for him to make his move.

Grayvus turned his head, slowly, searching for any sign of his Scouts.

Nothing.

He smiled. They were learning.

Grayvus returned his attention to the courtyard. His finger tensed on the trigger of his weapon. Just a second longer...

It moved again. He depressed the trigger, spraying a round of hot bolt-fire across the flank of the concealed beast.

What followed happened in a blur of movement so swift and so precise that Grayvus was almost caught off guard.

The tyranid creature emitted an angered howl, spinning around with surprising agility and leaping over a ruined wall towards its attacker. Grayvus could see now that his instincts had been correct — the thing was a lictor: three metres tall, with a hard, pink chitinous shell and a festering mouth filled with wriggling, writhing proboscises. Its eyes gleamed an angry red and two immense, bony blades scythed the air above it, the ferocious tips of extra limbs that jutted up and out from its shoulders. Its ribcage was covered in a series of angular barbs that Grayvus knew, from experience, were to be avoided at all costs. And it smelled like death. Like the very essence of death itself. It was a scent that Grayvus would never forget. Althion IV would be burned in his memory forever.

The creature raised its head towards the sky and howled once again before stalking forwards with menacing intent.

The scriptorium erupted into a cacophony of sound and a blur of movement: the roar of a chainsword, the bark of shotguns, the sound of boots crunching gravel. The ominous clacking of the lictor's claws against the broken flagstones. Where previously the only sounds had been the distant cawing of the birds, now the ruined building was filled with the riot of battle.

The Scouts materialised from the shadows like ghosts stepping between the fabric of worlds, grey camo cloaks billowing around their shoulders, weapons charged and ready; prepared, as always, for the battle to come. Grayvus backed away from the lictor as the others swarmed around it, encircling it, trapping it between them with an ease and discipline that made Grayvus's heart sing.

Grayvus squeezed the trigger of his bolt pistol again, loosing a hail of shots. The lictor thrashed around, unsure of which direction to focus its attack. Gravvus offered suppressing fire as Tyrus leapt forwards, his chainsword growling as he swung it around in a wide arc, lopping off one of the lictor's bony limbs with a single, easy movement. Green ichor gushed from the wound as the arm fell twitching to the ground. Tyrus fell back to avoid the slashing talon that threatened to decapitate him in retaliation.

'Concentrate your fire on its head,' bellowed Grayvus as he strode forwards, raising his weapon and firing directly into the nest of tentacles that swarmed around the monster's gaping mouth. The lictor screeched in defiance. It lashed out to the left, catching Corbis hard with a flick of its remaining clawed arm, sending him sprawling to the floor, his shotgun spitting wildly into the sky as his aim was knocked violently askew. He rolled across the flagstones and remained there on the ground, still, his face hidden from view. Grayvus wondered if the Scout's neck had been snapped by the ferocity of the blow. He had little time to worry about it now.

A second chainsword roared to life and Grayvus heard it biting into the thick chitin plates that covered the creature's back, whining as it cut through layers of bone and gristle. Another of the Scouts was assaulting the lictor from behind. Tyrus, meanwhile, had pulled his bolt pistol from his belt and was showering the lictor's head with a volley of hot slugs, taking Grayvus's lead. The creature buckled, one of its legs folding beneath it, as the Scouts continued their onslaught.

'Bring it down before it can call for more of its kind!' Grayvus called as he moved to the left, trying to close the gap left in the circle by the prone Corbis, all the while keeping his black eyes fixed on the beast, his weapon trained on its head. It wouldn't do to offer the monster an escape route. Lictors hunted alone, but their kind were never far behind; if they didn't bring it down swiftly, its pheromones would bring swarms of the things down on them.

There was a cry from behind the lictor. Avyn or Shyal — Grayvus couldn't see which. But he could see the creature's barbed tail flick up over its shoulder, blood dripping from the bony protrusions that crested its tip.

Grayvus felt something thunk into his chest plate and cursed that he'd allowed himself to be distracted. He looked down in horror to see one of the lictor's flesh-barbs had embedded itself in his armour. Extruded from the alien's chest, the barb was attached to a glistening tendril of thick, ropey flesh. The lictor jerked and Grayvus lurched forwards, only just managing to retain his footing. The creature was drawing him in, pulling the tendril back inside itself and dragging him closer in the process. Its slavering proboscises — or, at least, those that still remained after the rounds of bolt-fire that Grayvus had shot into its face — quivered with anticipation. This was what he had seen on Althion IV.

The horror of what those tendrils could do. He wouldn't let it happen to him.

Grayvus dropped his bolt pistol and kicked backwards, allowing his feet to come up off the ground and throwing all of his weight against the pull of the lictor's tendril. The barb held, and although the xenos staggered, it remained firm, continuing to drag Grayvus closer.

Grayvus took a deep breath. His next move was all about timing. Around him, the other Scouts were still pounding the lictor with bolt-fire and swipes from their chainswords, and he could see it was close to death. Syrupy ichor ran from numerous wounds in its torso and the air was filled with the stench of scorched bone and seared flesh. But the creature's eyes still burned with fury and he knew that it would not stop, not until it had burrowed its unholy, bone-tipped probes inside his head and stolen his memories, absorbed all of his thoughts. Death was one thing — a thing he would welcome when the time came and he knew that he had proved himself to the Emperor — but this alien, this monster, it represented something else. The loss of everything he was. He would not allow this creature inside his head.

Grayvus's feet skittered across the shattered floor of the scriptorium. The creature was close now, so close he could feel the heat of its foetid breath. He flexed his shoulders, readying himself. Then, in one swift movement, he reached up and clasped the grip of his chainsword, tearing it free from its holster and thumbing the power. He swung it round before him, at the same time allowing his body to go limp, forgoing all resistance so that he was pulled sharply forwards towards the straining lictor. He collided with it, caught for a moment in its bony embrace.

For a moment he thought he saw a flicker of triumph in the alien's eyes as it readied itself to feast on his mind, before it realised the chainsword was buried to the hilt in its chest, thrumming with power, wedged there by the force of its own trap.

The lictor screamed as Grayvus forced the chainsword up and out of its torso, ripping through organs and muscles and bones until, at last, the roaring blade burst free, slicing unceremoniously through its neck and finally silencing it forever. The alien wavered for a moment before toppling to one side, Grayvus still tangled in a heap of limbs beneath it.

'Get me out of here,' he barked at the others, who still stood in a circle around the dead beast, looking on with something approaching awe.

Sometimes, in the stillness, the quiet moments of anticipation before a battle, he thought of Deliverance. He remembered the clusters of smouldering venting towers, erupting from the moon's surface like bristling spines, puncturing the grey regolith to belch oily fumes into the midnight sky. He recalled the constant rumbling beneath his feet: the reverberations of subterranean mining engines, coring out the centre of the tiny world, harvesting minerals to feed the scores of ever-hungry forges and manufactories. He saw the dark, towering monolith of the Ravenspire, silhouetted against the planet-light of distant Kiavahr, and thought of home.

He hadn't returned to Deliverance for nearly a century, drawn instead by the constant need to protect these outer worlds on the fringes of the Imperium. Or — he smiled grimly — to protect the local human forces from their own incompetence.

Perhaps, in truth, there was more to it than that. Perhaps something else was keeping him away. He buried the thought.

Idos was a backwater, a long way from that half-remembered home. A world infested with the stink of xenos, fodder for the enemy spawning pools. Yet Idos had been granted the Emperor's protection, and the Raven Guard were there to ensure it was enforced. And besides, any opportunity to halt the advance of a tyranid hive fleet was an opportunity worth taking. He'd fought tyranids before, back on Althion IV, and he knew them for the abominations they were. A plague, a virus — a scourge that needed to be purged; they had infested the galaxy and obliterated innumerable worlds with their insatiable appetite for the raw materials from which they procreated. Yet the tyranids were an enemy that he could understand. Their motives were simple, their strategy pure. They wished only to feast on the biomass of a world, to conquer it and consume it completely, and they would take it through weight of numbers alone. Single-minded and devastating.

Captain Aremis Koryn surveyed the ruined landscape before him, the grassy plains covered in straw-like grass, the undulating hills and ridges that formed from the shattered wreckage of Proxima City in the distance.

It was too late for this place. He knew that already, an indisputable truth. His Raven Guard would halt the flow of the xenos, but the planet itself would never recover. Too much had been lost, and the world was too far out on the rim of the Imperium for it to be worthy of rebuilding. The native warriors knew that, too. It was what had driven them to such desperate measures, to using inferior weapons in an attempt to destroy the hive ship that hung in planetary orbit: a moon-sized abomination. Their targeting had been off, however, and instead they had inadvertently destroyed their own moon, Helion, splintering the worldlet into a billion fragments that now-wracked Idos below with fierce meteor storms and gravitational instability. And all the while, the xenos kept coming, an insatiable maw devouring the planet.

Koryn looked down upon the serried ranks of Space Marines, their black armour gleaming in the morning sunlight. To his left, bike squadrons formed a protective flank, covering the line of trees in case anything emerged unexpectedly from the forest. To his right, assault squads readied themselves for the coming onslaught, their talons glinting. And between them stood the main bulk of the Fourth Company, bolters at the ready.

The Raven Guard were few, but they would hold firm. This, to Koryn, was another indisputable truth.

Koryn himself stood upon the crest of a hill, resplendent in his ancient armour. It was an antique, worn for millennia by the captains of the Fourth Company, created in the Martian forges before the time of the great Heresy. It was engraved with the names of all those who had worn it before him and given their lives in service to the Emperor. A litany for his dead brethren, covering every centimetre of its pitted black surface. Koryn felt the burden of their memory, but also the honour of their company, the pedigree from which he had come. Today he would make his forebears proud. He would honour their memory. And one day his name would be added to theirs, etched onto a pauldron or leg plate or arm brace. One day he would give his life in the service of his Emperor, and it would be glorious. The thought gave him much comfort.

Koryn flexed his shoulders. On the horizon he could see the alien swarm approaching, a hazy cloud of buzzing wings, slashing limbs and putrid, slavering jaws. Behind the flared respirator of his helmet, he smiled. Soon his talons would taste alien blood.

Grayvus kneeled beside Corbis, rolling the young Scout over onto his back to check for any signs of life. Behind him, the corpse of the lictor still quivered nervously in its final death throes.

Corbis was tall but stocky, with a square jaw and a long, puckered scar running across his cheek from his left eye to his ear. His flesh was already beginning to lose its pinkish hue, becoming pale and translucent, and his hair had darkened to the colour of dusk: a sign that his melanochromic organ was flawed. He had the mark of the Raven.

Grayvus's flesh had long since been bleached by time and experience. His eyes, too, had lost their colourful hue, becoming orbs of the purest black, glossy pools of impenetrable darkness. He was older than the others and had seen combat in all its multifarious facets, had fought xenos and traitors alike on myriad worlds throughout the Imperium. It was his role to train the fresh-faced Scouts, to shape them into fully-fledged battle-brothers... if they managed to survive their training. And Idos was no simple exercise. The enemy was lurking around every corner.

Grayvus stood, his boots crunching on the splintered flagstones. 'He's breathing,' he announced, without ceremony. He walked over to where Tyrus and Avyn were standing over the prone form of Shyal, stooping to reclaim his bolt pistol from where he'd dropped it during the fight. His exposed arms were covered in lacerations and scars, as well as ichor and bodily fluids spilled from the chest of the lictor when he had brought it down.

'He's dead, sergeant,' said Tyrus, without turning his head away from the body of his fallen brother.

Grayvus glanced at the corpse. He most certainly was. Half of his face was missing from where the lictor's whip-like tail had caught him beneath the chin, crushing his jaw and pulping his right eye socket at the same time. His other eye remained open, as if staring expectantly at Tyrus, willing him to do something more. Dark blood was seeping out over the grey stone floor, forming glossy pools in the midday sun. 'He was probably dead before he hit the ground,' Grayvus said, his voice a low growl. He dropped to his haunches beside the  body. Shyal's camo cloak was wrapped around his ruined form like some sort of funerary shroud. Grayvus pulled it back to reveal the black armour beneath. The Scout's belt was adorned with the skulls of Kiavahrian ravens: tiny, yellowing heads with long, curved beaks, tied in a little cluster to a thin silver chain.

These totems, these corvia, were tokens of honour and skill. They were a representation of the raven spirit and a symbol of their home world. They were a measure of the Scout's aptitude and stealth, a part of the initiation rites through which the man Shyal had given himself over to the Emperor to become an Adeptus Astartes. Each initiate would prove his cunning by catching these birds in the great woodlands of Kiavahr, moving so silently amidst the lush flora that he could grab the avians where they perched, taking them with his bare hands and gently breaking their necks. It took months of practice and great skill for a Scout to be light enough on his feet and swift enough in his movements to grab the birds before they fluttered away.

Grayvus cupped the bundle of tiny skulls in his fist and pulled them free of the dead Space Marine's belt. He looked up at the others. 'Who will carry his corvia?'

Tyrus stepped forwards. 'I would be honoured, sergeant.'

Grayvus gave a swift, sharp nod and handed the totems over to the other Scout. 'Then remember that you carry with you his honour, also. He will rest when you return them to the soil from whence they came.'

The others waited in silence while Tyrus affixed the skulls to his belt beside his own. Grayvus turned to see Corbis climbing to his feet, rubbing his neck. 'You took your time,' he said gruffly, before gesturing down a ruined side street with the nose of his bolt pistol. 'Move out.'

The Scouts moved like shadows through the wreckage of Proxima City, silent wraiths picking their way amongst the dead. The city had yielded entirely to the invading alien horde. As Grayvus and his squad clambered over the debris of a toppled Administratum building, they realised the extent of the devastation. As far as they could see, in all directions, the city was in ruins. The jagged spires of fractured buildings were like misshapen teeth, clustered in a broken grin.

Dead civilians lay in rotting heaps, ready for the ripper swarms that would soon devour them, processing their flesh and blood and bones, feeding their raw biomass back into the tyranid gestalt. Within hours their constituent parts would be remoulded, formed into new alien paradigms. It was this that made Grayvus's skin crawl, this that appalled him most about the nature of the enemy: not only would they annihilate an Imperial settlement, but they would inextricably absorb it too, twist it and corrupt it and reform it in their own image.

Grayvus ground his teeth. The city had been decimated, shattered by the onslaught of the rampaging xenos and pummelled by the near-constant meteor storms as the remnants of the moon, Helion, rained down upon the planet below. There was nothing he could do to change that now. But he could halt the tide of stinking xenos. He could keep them away from the dead. The Raven Guard would have their revenge upon the tyranid filth. He would be sure of it.

Grayvus scrambled down the fractured remains of a colossal statue, swinging his bolt pistol in a wide arc, alert for any signs of danger. He heard Corbis drop down beside him.

'Sergeant, over here.' He glanced over at where Tyrus had slid down the other side of the ruined statue. Here, the head and shoulders of the monument lay half submerged in the dirt, the eyes of an ancient, unknown warrior staring up at them in silent vigil.

He crossed to where Tyrus and Awn were standing. 'What is it?'

Tyrus pointed at the ground near his feet. 'Spawning pools. They've already started work.'

Grayvus nodded. 'They'll be coming for the dead. Be on your guard.'

The Scouts edged around the glistening pools, pushing their way further through the wreckage.

As they neared the boundary of the fallen Administratum complex, Grayvus felt the hairs on the back of his neck prickle with warning. Something was close. He stopped, and the others followed suit, turning as one to regard him. The sergeant gestured for them to remain silent.

Creeping forwards, his bolt pistol tight in his fist, Grayvus approached the half-collapsed entranceway to the building, using what was left of the wall as cover. He peered out at the street on the other side.

Two enormous tyranid creatures were hovering amongst the wreckage, about thirty metres from the Scout's current position. They were unlike anything Grayvus had seen before: fat, bloated bodies crested by an array of chitinous plates and spines, each atop a long, curling tail that floated a metre above the ground. Their heads resembled that of the lictor, but bigger, their mouths ringed with squirming tendrils. Two small arms ended in vicious-looking talons. They were the colour of rotting flesh, pink and lurid, and towered at least three or four times the height of the Scout sergeant.

Grayvus watched as one of the creatures used its talons to skewer the corpse of a Guardsman from a nearby heap of shattered rockcrete, lifting it hungrily towards its tentacled maw. He turned away as the beast chewed noisily into its carrion meal. The sound of crunching bones made his skin crawl. His finger twitched on the trigger of his bolt pistol, but he held himself in check. He turned and made his way back to where the others were waiting in silence. 'We find another way around,' he said.

Tyrus offered him a quizzical expression. 'Is the way impassable, sergeant?' Grayvus nodded. 'Enemy hostiles block our path.'

Tyrus reached for his chainsword. 'Then we cut our way through.'

Grayvus put a hand on the Scout's arm, preventing him from drawing his blade. 'Sometimes, Brother Tyrus, winning the battle means losing the fight. Remember your training. Our mission is to survey the situation behind enemy lines and report on our findings. We will not needlessly engage the enemy and put that mission in jeopardy.'

Tyrus relaxed his grip on his weapon, but Grayvus could see the fire burning behind his eyes. 'Yes, sergeant. Forgive me.'

Grayvus smiled. He recognised that same impulse himself, that burning desire to purge the enemy, to seek revenge for his fallen brothers. But he knew nothing of the strange creatures out there amidst the rubble, and would not put his squad and his mission at risk — not for his own, or for Tyrus's, satisfaction.

Grayvus glanced around the ruined building, looking for another route. Without warning, the vox-bead in his ear sputtered to life with a hissing burst of static.

'Sergeant Grayvus?' The voice sounded tinny and distant.

'Captain Koryn.' Grayvus moved further into the shattered building so that his voice would not draw the attention of the feasting xenos outside.

'State your position, sergeant.'

'We're on the eastern fringe of the city, captain. Approximately ten kilometres from the main engagement, just inside the Administratum complex.' The vox went silent for a while. 'Captain?' Grayvus prompted after a minute had passed.

When he spoke again, Koryn sounded distracted.

'Grayvus. There's a power station three kilometres north of your position. I need you to destroy it.' Grayvus frowned. 'Destroy it?'

'Yes. And don't leave anything standing. Cause the biggest explosion you can.'

'But we don't have any explosives, captain.'

'Then be creative, Brother Grayvus.' The voice was firm, unyielding.

'Yes, captain.'

'And sergeant?'

'Captain?'

'Be swift, too.' The link went dead.

Grayvus pulled his auspex from his belt and consulted the readout. Three kilometres of rubble and wreckage stood between them and the power station, not to mention the risk of lurking enemy combatants and the ripper swarms feasting upon the dead. And he had no idea how they were going to destroy a power station with only bolt pistols and chainswords. It would be a test of their mettle, and a test of his training.

Grayvus glanced up at the expectant faces of his Scouts. 'Our mission parameters have changed,' he said, unable to contain the wide grin that was now splitting his face.

The enemy swarm was more substantial than even the reports of his own Scouts had led him to believe. There were thousands of them, a great, shifting ocean of flesh and bone. Koryn watched from his place on the hillside as the oncoming tide of xenos swarmed in towards his Raven Guard and the Space Marines came to life; immoveable, holding firm in the face of untenable opposition. The noise was incredible: the chatter of bolter-fire, the pounding of taloned limbs, the rending of plasteel and metal, the screeching of the xenos as they fell in waves.

Heavy bolters punched the air somewhere behind Koryn, sending hellfire rounds whistling into the conflict below, splashing searing mutagenic acid over the howling aliens, burning their unclean flesh. The bike squads roared to life, churning the earth as they shot into the melee, bolter rounds spitting from their forward-facing emplacements, mowing down scores of tyranids as they ploughed through the chaotic ranks of the enemy army. To the right, talons flashed as the assault squads pinned the enemy's left flank, slicing through the mass of darting hormagaunts and termagants that clambered over one another to get at the Space Marines.

And in the distance, like an eye at the centre of a vast storm, the hive tyrant. It was immense: an abomination rendered in flesh and blood. Its great, crested head towered high above the rest of its kin, swaying from left to right, taking in the enemy positions. Its huge cannon belched fat gobbets of venom that scorched the earth where they fell. Its limbs terminated in long, scything blades that cleaved the air around it, hungry for the blood of its enemies. It carried itself with an air of intelligence uncommon to the other, more animalistic creatures that surrounded it.

The captain knew that this creature — this monster — was the node that held the aliens together, the conduit by which the orbiting hive ship organised its troops, ensured the mindless individuals of the swarm were not, in their multitudes, mindless at all. They were a gestalt — one organism formed out of many. But if Koryn could sever that link between them, if he could interrupt that flow of information from the central intelligence above... then they became nothing. They would lose their cohesion. They would lose their purpose. And an enemy without purpose was no enemy at all.

Koryn turned to see one of his veterans approaching, his ebon armour scarred by the marks of a thousand prior battles. 'Argis. It is time for us to join our brothers in the fray.'

Koryn could not read Argis's expression behind his faceplate, but there was hesitation in his voice when he spoke. 'Captain. We are few. The enemy are legion. We cannot withstand a full engagement with the xenos. If the battle becomes protracted... ' He let his words hang for a moment. 'As keen as I am to spill their foul blood, this is not our way.'

Koryn nodded. 'I hear your concerns, brother. But we must have faith. The Raven Guard will triumph this day.' Koryn knew he was taking an enormous gamble, playing a dangerous game. But that  was their way. They would not defeat this enemy through brute force alone. They would out-think it. They would lead it into a trap. It was up to Grayvus now.

'Watch the skies, brother-captain!' Koryn turned at Argis's cry to see two winged gargoyles sweeping out of the sky towards him, their fangs chattering insanely, their jaws dripping with venom. Their heads and backs were plated with the same pink armour as their larger, flightless kin. But their exposed bellies were soft and fleshy; the perfect target.

Koryn tested his lightning claws. They fizzed and crackled with energy. He held his ground, waiting as the creatures swooped closer. He became aware of the sputter of bolter-fire as others around him began firing indiscriminately into the gargoyle flock, which suddenly filled the sky in all directions. He heard the beating of a hundred leathery wings as the hillside was cast in deep shadow, the density of the baying flock momentarily blotting out the sun. Swathes of the creatures tumbled from the air like fleshy missiles, shredded by bolter-fire, colliding noisily with the ground by the Space Marines' feet. But the onslaught continued unabated.

Koryn kept his eyes trained on the two gargoyles approaching him from above. The beast on the left squeezed the trigger of its strange, bone-coloured weapon, spitting a fine spray of acid across the captain's chest plate and pauldrons. He ignored it, remaining perfectly motionless as the venom chewed tiny holes in his armour. He dismissed the warning sigils that flared up angrily inside his helmet.

Waiting... Waiting...

The gargoyles manoeuvred themselves in for the kill, swinging around to offer their viciously barbed tails to the Space Marine, aiming their poison-spewing weapons at his faceplate.

Still waiting...

Still waiting...

Koryn pounced. He sprang into the air, twisting his body and uncoiling like a tightly wound spring. He extended his talons skywards to skewer the gargoyles through their exposed bellies, impaling one on each of his sparking fists. His manoeuvre was timed to perfection. The gargoyles had no time to react, screeching in pain and fury, twisting on the hissing metal claws that now punctured their pink, alien flesh. Pungent ichors coursed down Koryn's arms.

He landed neatly, his fists still held aloft as if brandishing the splayed gargoyles as obscene trophies. They thrashed for a few seconds more, their wings beating his arms and his face, their claws scrabbling at his power armour, before falling still, nothing but dead weights. Koryn roared in triumph and lowered his arms, casting the twin corpses to the ground. His ire was up.

He glanced around him, seeing only the spatter of xenos blood as his brothers tore through the gargoyle swarm, bolters chattering away at the sky, lightning claws and chainswords flashing in the stuttering light of the battle.

Below, his sergeants were holding the line, keeping the aliens back, refusing to buckle. But Koryn could see them straining against the sheer numbers and unrelenting ferocity of the tyranid assault. It was time. There was nothing more he could do from his vantage point on the hillside. He had committed the Raven Guard to this course of action and if he failed, then it would be a glorious death. All that was left was to hold the line. All that was left was the fight.

Koryn charged down the hillside, his boots pounding the earth as he ran. He leapt into the fray, his weapons ready. The blood sang in his veins. This was why he had been created, what he was made for. This: the glory of battle. This: the smiting of the Emperor's foes. This: the great war against the enemies of man. This was his purpose, his entire reason for being.

Koryn allowed the hunger for battle to consume him, gave himself utterly to the fight. He became one with his flashing talons. He danced and parried, transforming himself into a whirling dervish of death amidst a sea of pink flesh and chitin. Xenos fell in his wake. He carved through them like a spirit passing through walls of solid rock, his lightning claws spitting and humming as they cleaved skulls and separated limbs from torsos. His ancient, ebon armour glistened with alien blood. He dragged air into his lungs and bellowed as he fought: 'Victorus aut Mortis!' The aliens came at him in a relentless tide, but he cut them down. He would hold the line. Grayvus would prevail.

Behind Koryn, the Raven Guard pressed forwards anew.

Grayvus studied the hololithic readout of his auspex and glanced warily up at the sky. It had taken the Scouts over half an hour to pick their way through the rubble of the Administratum building and now a fresh meteor storm was threatening the horizon, and also their progress. He could see fragments of planetary debris beginning to burn up in the upper atmosphere, leaving long, fiery streaks across the sky in their wake.

The storms had plagued the Raven Guard's campaign ever since their arrival on Idos, rocks and boulders hurtling indiscriminately out of the sky at incredible velocities; a terrible, deadly rain. Helion rain.

Grayvus shook his head at the thought of it. An entire moon destroyed, a planet now ravaged by meteoric storms and tidal instability. A planet plagued by the stink of xenos. Idos had once been an idyllic world on the fringes of the Imperium. Now it was a living hell.

A high-pitched whistling pierced the air. Grayvus tracked the trajectory of a fist-sized rock as it smashed into the outcropping of a nearby building. The masonry exploded with the deafening echo of stone striking stone. This was followed by another, then another, fragments of the former moon clattering amongst the ruins with the explosive force of successive heavy bolter rounds.

'Incoming, sergeant!' bellowed Tyrus, and Grayvus turned to see a hail of debris showering out of the fire-streaked sky all around them. Tiny stones pinged off his carapace; a larger piece struck his right arm brace, nearly knocking him from his feet. Another tore a deep gash in his exposed forearm. The blood looked startlingly bright against the wintery paleness of his flesh.

'Take cover!' he called to the others, scrambling for the nearest building. The others scattered. Corbis fell in behind Grayvus, running over to share the shelter of an immense, arched doorway. Much of the building had been destroyed and Grayvus knew that what remained of it would be little help when faced with a major impact, but it would offer some protection from the accompanying hail of debris. If they were lucky, the larger strikes would occur further afield.

Grayvus heaved a frustrated sigh. They would have to wait for the storm to pass. This was one enemy that neither their bolt pistols nor their cunning could defeat.

The meteor storm swept in, bombarding the city, pummelling what remained of the buildings into heaps of rockcrete and stone. Grayvus dropped to his haunches, listening to the rhythmic drumming of the impacts, the bellowing echoes of the distant explosions that signalled the larger impacts elsewhere in the city. The sounds sparked memories of Haldor and the battle for Exvrian, all those years ago, trapped inside the city boundaries, besieged by the traitorous Iron Warriors. If he closed his eyes and concentrated he could still hear the screams of the dying, echoing in the darkness of the ruins. The siege had lasted for innumerable days, and it was only due to the unrelenting campaign of Captain Koryn — hitting the Iron Warriors with a series of swift, surgical strikes, then melting away again before the traitors could muster — that the Imperial forces had broken the enemy and brought the siege to an end. By then it was already too late for the civilians, of course. They were all dead, killed by the constant bombardments, the lack of food and the raging fever, this latter a result of the sheer volume and proximity of the putrefying corpses trapped in the ruins.

A voice cut through Grayvus's memories, snapping his attention back to the present. 'You've fought them before, sergeant?'

Grayvus tore his eyes away from the hailstorm ravaging the city, glancing back at Corbis, who was regarding him with interest, leaning against a fragment of broken pillar, his shotgun clutched in his hands. Grayvus nodded. 'Althion IV. We were ambushed. Most of my squad were killed. We were inside the hive when they came out of the darkness and hit us, attacking with all the fury of the warp itself. Terrible, deadly things with four arms. Until then I'd assumed the tyranids were nothing but beasts, animals that lacked any real intelligence, a pestilence that infested human worlds because it didn't know any different. But those things — those genestealers — there was darkness behind their eyes, a keen intelligence that spoke of something else.'

Corbis was watching him intently. 'How did you survive when so many others fell?'

Grayvus stiffened. He heard no accusation in Corbis's gruff tone, but the questions, and the memories, stirred feelings of guilt within him. He could not explain why he had lived when so many of his brothers had died. 'I cannot say. I was blinded by rage. I killed five, six of the creatures, tearing them apart with my bolter and my fist. My brothers had wounded many of them before they had fallen, but my hatred spurred me on. I covered my armour with their blood. Then one of them caught me in the shoulder with its c laws, splitting my armour like a tin can. I was on my back. The thing was on top of me, its sickening jaws dripping toxins, its hot breath fogging my helm. I prepared myself. I was ready to die alongside my brothers. I had fought well and made my peace with the Emperor. And then a sudden burst of bolter-fire, and the creature was dead, shredded by explosive rounds. Erynis had saved my life.

'He was dead when I got to him, disembowelled and lying in a pool of his own blood. One other — Argis — was injured but alive. I carried him back to our base outside the hive.'

Corbis nodded gravely. 'What happened?'

Grayvus studied the Scout's face. He was young and had not yet witnessed a campaign on the scale of Althion IV. He did not know of the necessary lengths they would go to, to protect the Imperium from its enemies. 'We destroyed the hive. It was lost. We were too late, and too few.'

'The entire hive?'

Grayvus nodded. 'And now we are here,' he said, turning his head to watch the hailstorm showering the street outside, 'and so are those stinking xenos. This time, the Raven Guard will have their revenge.'

Grayvus jerked suddenly and let off a series of short, sharp shots with his bolt pistol. There was a soft thump amongst the clatter of meteors as something fell dead to the ground nearby.

Grayvus rose slowly from his crouching position, tracking his weapon back and forth across the street. 'Be ready, Corbis. Those things don't hunt alone.'

'What wa—' Corbis fell silent as a small tyranid creature — about the size of a large dog — hopped up onto a slab of fallen masonry just in front of him. Tiny meteor-rocks were pinging off its armoured plating, but the creature seemed unaffected by the constant pummelling from above. It turned and hissed at the Scout, baring its fangs and its long, curling tongue. It held a bone-coloured gun of some sort in its bony claws. It cocked its head and moved as if about to strike. Corbis squeezed the trigger of his shotgun and took the creature's head clean off. The stench of burning meat filled the air around them as the body slumped soundlessly to the ground.

Grayvus stepped out into the street and released a volley of bolt-rounds into the storm. He could see a pack of termagants swarming through the wreckage towards him, their heads bobbing as they ran, twitching as the debris from the shattered moon continued to stream down around them. He knew that they would not be alone: if there were termagants here, experience told him that there would be bigger and more ferocious tyranid warriors just behind them.

Grayvus waved for the Scouts to join him as he unleashed another round of bolts into the oncoming mass of aliens. Bodies shuddered and fell, but more swarmed over the top of their dead kin, drawing closer. Grayvus felt the sting of tiny stones puncturing his flesh, burying themselves in his exposed arms and cheeks. Bright, red blood began to course freely over his pale flesh. Behind him, Corbis was crouching with his shotgun balanced on some fallen masonry, picking off termagants, one at a time. The other Scouts emerged from their shelter too, following suit, dropping aliens with every shot.

A lucky blast of return fire from one of the termagants caught Avyl full in the chest, bowling him backwards. Grayvus heard him cry out as he fought at whatever it was that had struck him and was now attempting to burrow its way through his carapace armour. There was no time to help him. The sergeant raised his bolt pistol again, searching for another target.

And then he was being pitched forwards, the sound of a massive impact ringing loudly in his ears. The ground shook violently beneath him. Darkness swam at the edges of his vision. His last thought before the black cowl of unconsciousness swallowed him entirely was that they needed to get out of there as quickly as possible.

The battle raged with a fierce intensity. Koryn was surrounded by a sea of flashing claws, creatures scrabbling to climb over his power armour, striking him as they tried to get at the Space Marine inside. He fought them off with ease, carried along by his fury, swept up in a storm of death. His talons hummed and spat with electrical energy as he cut a swathe through the mass of pink flesh and bone.

He heard more than felt the meteor storm as the hail of tiny stones rained down on his armour, scoring the black ceramite where it fell.

Further afield, boulders hurtled out of the sky, decimating the clashing armies, tearing great furrows and ridges in the landscape. Impact craters formed huge pockmarks across the battlefield and chaotic piles of the dead lay all around them, xenos and Raven Guard alike swallowed indiscriminately in the waves of earth that rushed out from the site of each strike. Above, the sky looked as if it were on fire.

Koryn twisted sharply to the right, swinging his talons up to spear a hormagaunt through the head. He gave his wrist a quick jerk and the creature's face came away in a spray of sickly ichor. Its twitching body fell to the ground, but Koryn had no time to savour the moment: for every alien he killed another two took its place.

The vox-bead buzzed suddenly to life in his ear. 'Captain?'

Koryn grunted. The sound of another voice pulling him momentarily from the trance of the battle. 'Go ahead, Fabis.'

'We're ready, captain. The alien force is in position.'

Koryn grinned inside his helm, striking down another hormagaunt with a swipe of a lightning claw. 'Your timing couldn't be better, brother. Mount your attack. And may the Emperor ride with you.'

The vox crackled and went dead. Koryn spun, arcing around to catch another of the beasts that had managed to get behind him. He jabbed his fists through the hormagaunt's torso, pulling them apart to splay the creature open, spilling its organs in a bloody heap.

The ground shook as another massive meteor struck from above, gouging the landscape, ripping an immense furrow across the battlefield. Scores of aliens died in its wake, buried in the accompanying deluge of mud and loam. Koryn glanced up. The Raven Guard were still showering the tyranid army with bolter shells and frag grenades, but many of them were being thrown off course as they collided with the meteors that filled the sky, or worse, exploding in mid-air before reaching their targets.

He looked to the left. It was difficult to see through the tangle of grappling limbs, but the bike squads had now closed on the left flank of the tyranid army, closing off their escape route through the trees. Koryn laughed as he turned his attention back to the swarm of aliens, freeing his arm from the grip of a hormagaunt that was trying to scrabble up and over his leg. He crushed its skull in his fist.

His plan was working. With Fabis closing in on the xenos army from behind, flanking them with a Raven Guard force comparable in size to that under Koryn's direct command, they had the xenos pinned. To the right, like a great dam, were the walls of the ruined city. The tyranids were completely surrounded. Now it was a waiting game. All they had to do was hold the line. Koryn willed Grayvus to hurry.

* * *

Light bloomed before his eyes. Light, and the sound of raindrops striking the ground, a relentless pitter-patter, pitter-patter. Grayvus coughed and heaved himself up off the ground. He shook his head to clear the wooliness. The sound wasn't rain. It was tiny stones. It was Helion.

The memories flooded back into his consciousness. The meteor storm was still pounding the city. He couldn't have been out for long. He cast around, looking for his bolt pistol. He found it jutting out from beneath a pile of rubble and retrieved it, dusting it off. He stretched and felt a long gash on his left cheek tug uncomfortably. The flesh had already begun to knit itself back together, but his face was crusted with dry blood. Smaller wounds covered his arms like a spider's web, or a chaotic street map.

The scene all around Grayvus was one of utter devastation. Behind him, a large meteor had slammed into the street, toppling a basilica. The building's metal substructure had buckled and warped, and it now described a twisted skeleton against the sky, having shed its rockcrete skin. The ground itself had risen in a vast wave from the impact point, ruffling the earth like a rug pulled out from somewhere deep beneath the city. Steam rose from the impact crater like so many ethereal spirits, desperate to return to the warp. And all the while, the meteors continued to fall, stinging Grayvus's already battered flesh.

Grayvus realised he had been flung out over the lip of the crater during the impact. He began searching the immediate area for the other Scouts but found only dead termagants, their weak bodies crushed by the wreckage of the building or shattered by the force of the impact. One of them was still squirming, its back legs clawing pathetically at the exposed soil. It made a high-pitched mewling sound as he approached, and then hissed viciously as he stood over it, turning its lolling head with the edge of his boot. He put a bolt through its skull, not out of any sense of mercy, but simply to ensure it was dead.

'Sergeant?' He heard the call from over the other side of the crater and ran over to find Corbis crouched over the dead figure of Avyl. The fallen Scout's body was covered in a fine layer of grit and stone, and Corbis was brushing it away with his hand, searching for Avyl's corvia. He located the tiny bird skulls and Grayvus watched him tug them free, fixing them carefully to his own belt, a tribute to his dead brother.

'Was it the blast?'

Corbis shook his head. 'It was the xenos.' He indicated a hole in Avyl's chest carapace where the living ammunition that the termagant had fired from its weapon had bored a hole through to the Scout's chest, devouring his hearts.

'Where's Tyrus?'

'Down there.' Corbis nodded behind him. Grayvus started over, increasing his pace to a run when he heard bolt-fire coming from that same direction, assuming that the Scout had engaged the enemy. He crested a large mound of earth to discover Tyrus was in fact following his lead, quickly and effectively terminating any remaining aliens he found amidst the wreckage. He looked up when he noticed Grayvus watching.

'Avyl is dead. We have a mission to complete.' The statement was matter-of-fact, pointed. The authority behind it was implicit.

Tyrus nodded. Grayvus could see the Scout's knuckles were white where he clenched his bolt pistol hard. He was feeling the loss of his brothers keenly. Grayvus smiled grimly. Tyrus would have his chance to avenge the dead. And so would he. He would be sure of it.

The power station loomed out of the hailstorm like a jagged tooth, a towering edifice of pipework and fuel vats that spewed a constant stream of oily smoke into the sky for miles in every direction. This was the generatorium, until recently the power hub for an entire quadrant of the city. Amidst the destruction wrought around it, this leviathan was somehow still operational. Or at least, Grayvus considered as they approached through the wide, ruined street, something was keeping it running.

Grayvus and the two remaining Scouts ran through the pummelling rain towards their goal. Time was running out. It had been hours since their last communication from the captain, many of those hours lost to the meteor storm and their encounter with the termagants. Now was the time to act.

Grayvus scanned the approach to the generatorium before ushering the others forwards. He clipped his auspex to his belt and reached for his chainsword. He didn't know what to expect inside the building, but he wasn't about to be caught unawares.

Tyrus was first to approach the large, arched doorway. He stepped cautiously through the entrance, his bolt pistol braced and ready. A moment later he reappeared, indicating that the others should follow. Grayvus and Corbis kept their backs to the wall as they moved slowly around the doorway to join Tyrus inside.

The corridor beyond the door was dank and industrial, with bare metal plating covering the walls and floor, and exposed pipes worming their way through the passageways like a network of arteries and veins. It was dimly lit, with only flickering emergency beacons to guide them. The stench of oil and burning coal was almost palpable.

Grayvus motioned for the others to be silent. He listened for a moment, trying to discern any sounds of movement. There was nothing but the noise of a dripping pipe, echoing throughout the empty corridor. That and the continuous background sounds of the meteor storm, striking the building outside.

He looked up, meeting the eyes of the others. They were injured and bedraggled, but their eyes shone with a burning intensity. 'We need to find the reactor. That's the only way we can destroy this place without any explosives. We set it to overload, and we get out of here as quickly as possible.'

Corbis straightened his back and flexed the fibrous muscles in his neck. 'May the Emperor protect us.'

'We will do our duty,' was Grayvus's only reply.

They set off down the passageway, their boots ringing loudly on the metal floor plates. They passed along a series of almost identical corridors as they wound their way towards the heart of the structure. The low, red lighting cast long shadows, and the occasional clank of a pipe or the thrum of a power line kept Grayvus alert and ready.

'The place seems deserted, sergeant,' said Corbis, but as they turned a dogleg in the passageway it became instantly clear that it was not. A large, bulbous sphere hung in the air just ahead of them, a fleshy ball of pink and grey. A long tail hung from the base of it, which quivered like a twitching snake as they approached. The xenos had been here, and they had left this behind.

Tyrus hefted his bolt pistol and took aim.

'No!' Grayvus bellowed, foregoing all sense of stealth. But it was already too late. The bolt-fire lanced the spore mine, which exploded in a spray of searing acid, splashing across Grayvus's face and arms and raising instant welts in his pale flesh. His skin burned for a moment and he gritted his teeth and waited for the pain to subside. But Tyrus had taken the brunt of the explosion and he fell to his knees, clutching ineffectually at his face. His bolt pistol clattered to the floor.

Grayvus rushed to his side. 'Tyrus?'

'Forgive me, sergeant.' The voice was a stuttering lisp.

Grayvus prised the Scout's fingers away from his ruined face. The bioacid had done its work. Tyrus's right eye was nothing but a puddle of jelly in its socket, and where his cheek had been there was now only stringy remnants of flesh and muscle, exposing his hind teeth.

'You're alive, brother, and that's enough. Get up.' There was a hard edge to Grayvus's voice. 'We have a job to do.'

Corbis helped the wounded Scout to his feet. 'Can you see?'

Tyrus nodded but didn't speak. He stooped to reclaim his bolt pistol, and they moved on.

The corridors and passageways of the generatorium continued to wind into the dank depths of the earth. They were drawing closer to their target now, closer to the throbbing heart of the power station, closer to their mission objective.

They'd passed another three of the spore mines, but had crawled beneath them on their bellies, an undignified but necessary means of avoiding detection, ensuring the biological triggers did not detonate in the confined space of the corridors.

Now, they had come upon a bulkhead door that had been dropped across the corridor, blocking their way: one of the safety barriers that locked into place during a shutdown. Grayvus had considered turning back, finding an alternative route, but that meant doubling back and passing the spore mines again, and worse, it meant wasting time. He consulted his auspex. Going through the bulkhead was the quickest way to the reactor. They were only a matter of metres away. Once they were through they could set the reactor to overload and get out of there. They would have to break through with bolters and chainswords.

He was about to outline this plan to the others when he heard a distinctive tap-tap ringing out against the metal floor plates. He glanced at the others inquisitively but was met with only blank stares. He hesitated, a cold sensation spreading across his chest. There it was again, tap-tap, like the clicking of a claw. Grayvus stiffened. His finely tuned hearing had detected breathing now, a ragged, rasping breath. A hissing. Something drew a claw across a wall plate, scratching a loud warning. It was toying with them. He knew what it was. They'd been herded into a trap.

Grayvus turned to see not one but two genestealers appear at the far end of the corridor, their heads bobbing, their multiple, viciously clawed arms tapping the walls menacingly as they approached. Wriggling proboscises surrounded their mouths and their eyes were blood-red and shone with a startling intelligence. They crept forwards, taking their time with their cornered prey.

The Scouts formed a line, keeping their backs to the bulkhead.

'Don't let them get close!' Grayvus barked. 'Don't let them get anywhere near you.' He knew first-hand what this genus was capable of.

Grayvus squeezed the trigger of his bolt pistol, spraying the genestealers with shells. But the creatures were too fast. They pounced, launching themselves into the air, springing off the walls to land only centimetres away from the Grayvus and the others. Grayvus's bolt pistol went spinning away down the corridor, wrenched from his grip by a glistening talon.

Corbis squeezed off a series of shots with his shotgun, catching one of the genestealers across its left flank, slowing it for only a second. It whipped out a claw and pinned the Scout by the throat, dragging him closer, its proboscises writhing with anticipation.

'No!' Grayvus's chainsword roared to life. He would not let this happen again. And he would not fail his captain.

He charged the nearest alien, swinging his chainsword in a wide arc, aiming to take off its head. The creature swiped at him with a claw, battering his blade to one side and sending Grayvus sprawling to the ground. He wasn't staying down, however, and twisted quickly up onto one knee, forcing the chainsword up. The genestealer's claw came down, centimetres from his head, but clattered uselessly to the floor as Grayvus's blade tore through the alien's carapace, chewing out its belly. It squirmed and thrashed, but Grayvus pressed the blade home even harder, twisting it round to maximise the damage. He stood, grabbing a fistful of the quivering mouth tentacles, yanking the creature's head to one side. The alien's claws raked his chest plate as it tried to pull itself free, but Grayvus was lost to his rage. He left the chainsword buried in its innards and reached for his combat knife. He looked deep into the creature's eyes as he buried the knife to the hilt in its exposed throat. 'That's for Erynis,' he whispered, as he saw the life flee its body. The genestealer squirmed once in his grasp and then fell still. Grayvus dropped the corpse to the floor.

Beside him, the other genestealer still had Corbis pinned by the throat but was also grappling with Tyrus, who had managed to draw his chainsword and was busy sawing his way through the creature's chitinous armour plating. He was bleeding freely from a long wound in his arm. Grayvus calmly pulled his own chainsword free of the corpse at his feet, stepped across the corridor and wordlessly lopped off the head of the occupied genestealer. It fell to the metal floor with a dull thunk and the body went limp. Corbis and Tyrus both disentangled themselves from the mass of limbs. Tyrus was breathing heavily. What with the acid burns and the fresh injuries caused by the genestealer, he was in a bad way.

'I told you not to let it get close to you,' Grayvus said, without a hint of irony in his voice.

Corbis laughed grimly. 'What now?'

Grayvus motioned to the bulkhead. 'Through there. The reactor is on the other side of this barricade. Corbis — see if you can breach it with your shotgun.' He stepped back to make room for the other Scout. 'And be quick. I don't want to be cornered by any more of these things' He kicked at the dead remains of the nearest genestealer and moved off in search of his bolt pistol.

The shotgun soon punched a series of irregular holes in the thick metal plating causing the steel to splinter like rotten wood. Grayvus kept watch, keen to avoid another encounter with the genestealers that were likely haunting the corridors around them, drawn in by the sounds of the battle. Presently, however, the bulkhead issued a long groan and a large section of plating dropped inwards, clanging loudly where it fell.

Corbis called him over.

Grayvus approached the makeshift door, his bolt pistol clutched in his fist. He could see little through the hatch but a bank of winking diodes and controls: the reactor room. He dipped his head and pulled himself through the opening.

And that's when he saw it: the biggest tyranid biomorph he had ever seen, squatting inside the reactor room, its enormous, dripping maw bared in what he could only imagine was a wicked smile.

Koryn thrust and cut, parried and spun: a riotous dance of destruction. He could barely see for the blood spray hanging in the air all around him. He was injured, but was choosing to ignore the warning sigils that flashed up inside his helm, alerting him to the deep gash in his thigh. Analgesics had already flooded the area and his body would have time to repair itself later. If he survived.

Many of his brothers were dead. He knew that instinctively. He had no need to witness the sorry ranks of the lost, the discarded bodies, ripped apart by uncompromising alien jaws. He knew it, and it filled his heart with sadness. The Raven Guard were few and they could ill afford to sacrifice themselves. But his brothers had died with purpose. They had died in the glory of battle, holding the tyranid army at bay while their brethren engineered the means of their victory. He only hoped that Grayvus was close to achieving his goal. They could not hold out for much longer. Koryn could see the hive tyrant was growing restless. The end was in sight, one way or another.

* * *

Grayvus eyed the creature warily. It was huge, towering at least three times his height, with a flared crest of blood-red chitin atop its massive head. Its lower jaw was wide and pink, splayed like a shovel and connected to two mandibles that twitched ominously from side to side as it regarded him. Its fangs were as big as his forearms and coated in dripping venom. Its body was long and snake-like and — Grayvus realised — disappeared into the ground, from where the monster had evidently burrowed its way into the generatorium, digging its way in from beneath the city. Three huge pairs of limbs terminated in scything talons, with two sets of smaller, more human arms bursting out from its chest. It filled the reactor room utterly.

The creature emitted a shrill chirp and shifted its bulk, lowering its head to show them its fangs. Its foetid breath smelled of moist earth and decay. It couldn't twist itself around enough to reach them with its talons.

Once again, Grayvus was taken aback by the intelligence displayed by the xenos. Had they known the Scouts were coming? Was that why the biomorph had burrowed its way here? Or worse, had they planned to use the same trick? Were the tyranids actually intending to use the power station for the same purpose as the captain, to detonate it at a time when it would prove most devastating to the Imperial forces? Either way, they had been out manoeuvred.

'What is it?' Corbis was standing beside him, staring up at the monstrous thing.

'It's between us and the reactor,' was Grayvus's only response.

Tyrus stepped forwards, brandishing his chainsword. 'This time, sergeant, I think we're going to have to cut our way through,' His slurred voice was barely recognisable.

The Scout was right. There was little else they could do. 'Corbis. Get to that reactor. Tyrus and I will keep it occupied.' Grayvus raised his bolt pistol. 'We don't have to kill it, Tyrus, just keep it busy. The reactor will do our job for us if we can get to it.'

Tyrus nodded, but Grayvus wasn't clear whether it was in understanding or something else entirely. The injured Scout seemed distant, distracted.

Corbis approached the creature tentatively, trying to search out the best route to the reactor. He moved left and it howled like a baying wolf, slamming its talons down into the churned earth, trying its best to reach him. The bony blades scratched the walls in frustration. Corbis fell back, raising his shotgun and loosing a handful of shots. They pierced its flesh but did little more than anger it.

Tyrus fired up his chainsword. He extended his arm and placed something in Grayvus's hand. It was a tiny bundle of bird skulls. 'Honour me, sergeant, in the fields of Kiavahr.'

'Tyrus!'

The Scout charged forwards towards the beast, his bolt pistol flaring as he fired round after round into the creature's open maw. It screeched in fury and lashed out with its scything talons, one of them catching him full in the chest, bursting out of his back and spattering Adeptus Astartes blood across the room.

Tyrus growled in agony as he was lifted fully from the ground. His chainsword roared, biting deep into the monster's flesh, as it pulled him closer to its slavering jaws.

'Corbis. Get to that reactor, now!' Grayvus swung his bolt pistol around and fired into the alien's wide mouth, satisfied to see the bolt-rounds flashing inside its head as they exploded brightly, cracking its teeth. The creature reared its head and thrashed alarmingly, swinging Tyrus violently from side to side. Tyrus was still alive, barely, speared on an outstretched claw. With one hand he was firing his bolt pistol into its face, with the other he was driving his chainsword repeatedly into the thick hide of its torso, searching for any vital organs.

Gravvus moved back and forth in a wide semi-circle, keeping his weapon trained on the monster, firing clip after clip at its head, desperate to keep it from realising that Corbis had now passed it and was working on the reactor controls behind it. He reappeared a moment later, scrambling over the mound of earth and rushing towards Grayvus.

Too late, Grayvus saw the arcing talon as it swung down from above, catching Corbis square between the shoulders and pitching him forwards. The Scout stumbled and dropped. The talon raised again, ready to finish the prone Corbis.

Grayvus dived forwards, grabbing at his brother and flinging him across the reactor room. The talon sliced down, puncturing his shoulder and opening his chest, bursting a lung. Grayvus slumped to the floor. The world was spinning. The creature pulled Tyrus's now unconscious body towards its mouth and chewed off his head.

Behind it, the reactor was reaching critical levels, warning sirens blaring.

Grayvus saw only darkness.

Koryn heard the explosion from almost four kilometres away, even above the clamour of the raging battle, even above the screams of the dying aliens and the screeching of their claws across his power armour. He heard it, and he knew they were victorious.

The ground rumbled and groaned, knocking him from his feet. He heard the vox-bead buzz in his ear but made no sense of the words as, all of a sudden, the planet seemed to lurch violently to one side. He heard a sound like rending stone and scrambled to his knees in time to see the city walls give way, crumbling to the ground as titanic forces rent the earth apart. All around him, the tyranids were scrabbling for solid ground, their animal minds unable to comprehend what was happening.

Koryn caught sight of the hive tyrant, its head thrust back, bellowing insanely at the sky. He watched as the ground cracked open beneath it, sucking the creature down into its rocky depths, pulling it into the canyon opened by Grayvus's destruction of the power station. It was as if the planet itself was enacting its revenge against these insidious invaders, swallowing them whole, crushing them with its immense power. The Raven Guard had executed their plan to precision: the fault line had opened right beneath the heart of the tyranid army, exactly where the Space Marines had pinned it in place.

Scores of aliens spilled into the newly opened crevasse like a tide, unable to prevent themselves from falling. Their screams were a violent cacophony, a tortured howl that Koryn would never forget. That was the sound of triumph. That was the sound of the Emperor's might.

Those aliens that still swarmed around Koryn himself seemed suddenly to lose direction, their psychic link with the hive mind interrupted by the death of their tyrant. They pressed on with their attack, but they had lost their cohesion, their underlying purpose, and were now fighting on instinct alone. It would be a simple matter for the remaining Raven Guard forces to mop up what was left of the alien brood.

Koryn sliced another alien in two with his talons. He was covered in xenos blood and his leg wound was still causing warning sigils to flare incessantly inside his helm. He watched as a group of hormagaunts turned and fled from an approaching assault squad, who showed no mercy, mowing down the retreating aliens with their bolt pistols.

He turned to see Argis approaching from behind, striding across the battlefield towards him, his power armour rent open across the chest in a wide gash, his bolter hanging by his side. Clusters of  corvia hung from his belt, signifying the losses his squad had sustained during the thick of the battle. The veteran stopped beside Koryn, surveying the scene across the battlefield. After a moment, he spoke. 'Faith, you said, captain.'

Koryn nodded. His voice was subdued. 'Faith.'

Argis put his hand on Koryn's pauldron. 'That is most definitely our way.'

Grayvus sucked noisily at the air and winced at the lancing pain it caused in his chest. He peeled open his eyes. He was outside, slumped against a wall. The meteor storm had abated and the sun was perforating the clouds. His mouth was full of gritty blood and he was gripping something tightly in his fist. He glanced down. It was Tyrus's corvia. He allowed his hand to drop to his lap. He would take them back to Kiavahr, bury them in the soil from whence they came.

Corbis was standing over him. When he saw Grayvus was awake, his pale face cracked into a wide grin. 'Sergeant.'

Grayvus spat blood. 'Corbis. You should have left me.'

Corbis didn't answer.

Grayvus stared over at the enormous cavity that had opened in the ground behind them. The power station had been completely subsumed. What remained of it after the explosion had slid noisily into the hungry earth, tumbling down into the depths of the fractured landmass. Its destruction had opened a canyon across the face of Idos like a long, puckered scar, a fault line stemming from the site of the explosion and stretching for kilometres in both directions. Much of the city had been swallowed in the ensuing devastation. And the biomorph, too, along with most of the tyranid brood.

Corbis dropped to his haunches beside the wounded sergeant. 'What now, sergeant?'

Grayvus put his hand on Corbis's shoulder pauldron. 'Now, brother? Now you may call yourself Adeptus Astartes.'

ABOUT THE AUTHOR

George Mann has written two Raven Guard audio dramas for the Black Library, Helion Rain and Labyrinth of Sorrows. He is the author of the Newbury & Hobbes steampunk mystery series and has written new adventures for both Sherlock Holmes and Doctor Who.

He lives in Grantham, UK, with his wife, children and rather large collection of books.

ABOUT THE ARTIST

Karl Richardson was desperate to escape a life of painting greetings cards on the mean streets of Leicester and scaled the fence many years ago to draw Space Wolves. Unfortunately, the Black Library didn't have a Space Wolves comic strip at the time so he was forced to cut his teeth on the second book of Daemonifuge until the day he received the call from Fenris. Karl hasn't looked back since... except for on the occasional rainy afternoon when he can still be found working on the odd Valentine's Day or Christmas card.