His vision began to clear, enough to see Dralzir vault the barricade and bury his chainsword in the plasma gunner's neck, the teeth whirring madly as they tore through one of the variant plate's few weak points. He drove the weapon in deep, ripping into flesh, churning through meat and bone. Blood drenched the sergeant's faceplate and chest.

A bolter fired from behind the barricade. Dralzir staggered, struck from behind, and fell forwards over the mutilated body of the Ultramarine he had just cut down.

Now Marduk had a target lock once more. He squeezed off a pair of quick shots, but they missed the mark by scant centimetres. He was about to fire again when a red-armoured figure cut in front of him.

Burias.

Marduk cursed his name, and broke into a run.

Dralzir was trying to rise, struggling to push himself up off the ground. It was impossible to see the extent of his injuries, but it was clear that he was seriously wounded by his sluggish, pained movements.

'Whatever you traitors hope to achieve, it will fail!' roared the Ultramarine, leaning forward and jamming his gun barrel into Dralzir's exposed neck seal, ready to execute the Word Bearers sergeant. 'Know that before you die.'

'Infidel!' screamed Marduk as he drove forwards, only a few steps behind that over-eager fool Burias.

Two shots rang out, the bolts' detonation taking Dralzir's head almost completely from his neck and blowing out his eye lenses. He crashed down and blood pooled beneath him, and the Ultramarine shoved his body away.

Marduk spat, and grunted in frustration. Burias was still obscuring his shot.

With a bellow, the headstrong young novitiate leapt over his fallen sergeant's corpse, bringing his chainsword down in a double-handed blow. The Ultramarine used the stock of his bolter to block, but the roaring adamantium teeth still bore down towards the legionary's helmet, chewing and spitting against the weapon's casing.

With a swift movement, the Ultramarine stepped to one side and turned, shifting the angle of his bolter sharply and unbalancing Burias. The momentum carried the novitiate forwards, his chainsword roaring as it lost traction and slid down to the deck. Stepping back in close, the Ultramarine brought his elbow around in a perfectly timed strike that hit Burias square in the faceplate as he staggered into it.

The force of the blow dropped him onto his back, hard. He lay there, momentarily dazed. One of his visor's lenses had cracked, and his faceplate was visibly buckled.

Without pausing, the Ultramarine rounded on Marduk, but the Word Bearer was upon him before he could fire, slamming into him with a lowered shoulder. The armoured impact lifted the Ultramarine off his feet and drove him into a stabilising pylon, which gave a groan of tortured metal as it was wrenched out of shape. The Ultramarine's weapon clattered to the floor and Marduk kicked it away, sending it skidding across the deck.

The legionary recovered quickly. He grabbed Marduk and pulled him into a knee strike that took him in the midsection. The force of the blow would have broken a lesser being that was clearly what the warrior had been trained for, not the killing of other Space Marines. Until this day, the merest thought of such a thing would have been beyond his dim comprehension.

But not for Marduk.

He had killed Space Marines before. Battle-brothers of his own Legion, no less.

Still, the Ultramarine was a fast learner, as were all the warriors of Ultramar; they were not to be underestimated. Another sharp knee sent a hairline fracture splintering up Marduk's breastplate, and integrity warnings flashed within his helm. Rising fast, he struck the Ultramarine under the chin with his bolter, snapping his head back sharply.

The legionary reeled, and Marduk had a clear shot, but even as he squeezed the trigger the Ultramarine slapped the weapon aside. The report was deafening, but the bolt missed, slicing past the Ultramarine's smooth faceplate.

The veteran XIII Legion warrior had a hold of Marduk's bolter then, and he disarmed him with a vicious twist of the weapon's grip. He planted a boot squarely in Marduk's chest, sending him stumbling backwards, and took aim with the bolter.

Behind him, a chainsword revved.

The Ultramarine spun, turning aside from the murderous, decapitating strike from Burias. He avoided another wild blow and planted a fist into Burias's already damaged helmet. Sparks danced across the shattered faceplate. The stolen bolter came up again.

Marduk grappled him, wrapping an arm around his neck. In his other hand he held a blade not a combat blade, but his sacred athame, its hilt wrapped in copper wire. The Ultramarine dropped the bolter, grasping at Marduk's arm, but the Word Bearer's grip was like iron.

'The gods will feast on your soul, son of Ultramar,' Marduk hissed.

'There... are... no... gods!' the stricken legionary choked.

'You've been lied to,' said Marduk, 'but you'll know the truth soon enough.'

He wrenched the Ultramarine's blue helmet to the side, exposing the vulnerable fibre-bundles and cabling behind the gorget, and rammed his blade in.

The Ultramarine was not dead, though he was as good as.

Joint servos and interlocking gears whined as he continually struggled to rise. His strength was all but gone, and Marduk kept him pinned to the deck, one foot pressing down hard against his breastplate.

Blood had pooled. It was already congealing, turning the deck into a sticky, clinging quagmire. It continued to flow sluggishly from the Ultramarine's wounded neck. Even the hyper-coagulants in his bloodstream were unable to seal the cut that Marduk's athame had made.

He writhed weakly, gauntleted fingertips twitching.

'What are you doing?' demanded Burias. The novitiate still hovered at Marduk's shoulder, casting nervous glances up and down the corridor outside as the sounds of battle rang through the platform's superstructure. 'Just kill him.'

'Wait,' said Marduk.

'For what?'

'I want to try something,' said Marduk. 'Watch. Learn.'

He took his boot off the Ultramarine's chest. The breastplate groaned at the release in pressure. The legionary tried to push himself upright, lifting himself on one shaking, faltering arm. Marduk kicked it out from under him, and he fell back to the deck with a crash of ceramite on metal.

Kneeling, he cradled the Ultramarine's crested blue helm in his hands. Disengaging the locking seals, he removed the helmet with a hiss of venting air pressure and placed it to one side.

The warrior's face was an unhealthy, ghostly pallor. What little colour remained was being drawn out before Marduk's very eyes. It made the splash of blood upon his neck and cheek appear even brighter in contrast.

He had a strong, proud visage: angular and imbued of a cold, arrogant nobility that was utterly foreign to one born on Colchis. It was the lined, careworn face of a senator or a diplomat not a warrior, in spite of the scars, the blood and the three service studs embedded in his brow. Red foam bubbled on his lips. He struggled to focus upon his tormentor with eyes the colour of iron.

'Lorgar... is sending... children to fight us now?' breathed the Ultramarine, with a hint of cold mirth.

'I am no child,' snapped Marduk.

'But you are... a traitor...'

'History will not regard us so. We will be hailed as the heroes of this war, those who ushered in a new era of understanding and belief.'

The Ultramarine gurgled something that might have been a derisive laugh.

'You are... a foolish youngling,' he said. 'You will learn... the folly... of... of your actions.'

'Let me show you what can be achieved with true belief, noble son of Ultramar,' Marduk snarled. He leaned forward and placed a hand upon the Ultramarine's chest. The dying legionary jolted. 'Let me show you the power of the gods you would deny.'

'What is this?' hissed Burias, seemingly unable to look away.

'Can I trust you, brother?'

'Of course. Always.'

'Then be silent,' said Marduk, and closed his eyes.

Shapeless things writhed in the darkness behind his eyelids. Amongst them he felt the presence of another his true mentor. It pushed to the fore and the rest gave way before it. He felt its presence swell, testing the boundaries of reality. It longed to be made real.

Soon, he promised.

He breathed deeply, turning his focus inwards. Unreality blossomed like a flower, unfurling itself, and the sentient darkness spoke to him.

It knew what he wanted. It whispered to him, a thousand voices blended together into one insidious drawl. It spoke directly into his head, each unfathomable vowel and syllable stabbing into his brain like an incision.

Feal'shneth'doth'khaerne'drak'shal'roth.

Marduk opened his eyes.

The Ultramarine looked up at him, his unfocused gaze one of pure horror. He tried vainly to pull away. Even with his blunted mind he could feel that something was happening.

'Feal'shneth'doth'khaerne'drak'shal'roth,' Marduk intoned.

An electric itch crept beneath his amour, beneath the sub-dermal fibre-bundles and cabling of his mechanical musculature, beneath the bonded black carapace that was as one with his flesh. His eyes itched from the inside. Insubstantial tendrils scratched at the interior of his skull.

Dol'atha'lin'korohk'bha'naeth'la'kor.

'What is that?' hissed Burias, looking around them in the growing gloom. 'Where is it coming from?'

Marduk ignored him.

'Dol'atha'lin'korohk'bha'naeth'la'kor,' he said. He felt the power in the words even as he spoke them. They made his lips tingle and sting. He tasted an acidic burn on his tongue.

But it was working.

The Ultramarine began to shudder, moaning softly. He convulsed on the deck, turning his head from side to side. His eyes had rolled back, with only the blood-flecked whites now visible.

Raeth'ma'goerdh'mek'koeth.

Burias had fallen silent. Marduk was thankful for that.

'Raeth'ma'goerdh'mek'koeth.'

The Ultramarine's muscles tensed in a sudden, violent spasm that curved his back and lifted him off the deck. Marduk kept his hand firmly upon the legionary's chest.

The breastplate had begun to smoke beneath his touch.

Things moved beneath the Ultramarine's flesh, like ripworms wriggling under the skin. His armour began to bulge at the seals, as of great pressure building within.

'Blood of the Aurelian,' whispered Burias.

Bony spurs and thorn-like barbs rose along the edges of the Ultramarine's armour, twisting and contorting the armoured plates of his suit. It was of a design unfamiliar to the Word Bearers, but its regal lines were now marred by a more pleasing, corrupted aspect.

The Ultramarine's eyes were screwed tightly shut now, and bloody tears began to flow from their corners. When they snapped opened again, his eyeballs were gone, revealing only hollows of darkness rimmed by small, jagged teeth. Those teeth began to chatter. Burias laughed.

The Ultramarine scratched at his own face with fingers turned to claws, ripping at his flesh. Wriggling things were revealed in those rents ribbed, leech-like things with snapping lamprey mouths. An anguished cry escaped his lips.

'Don't fight it, kinsman,' said Marduk. His hand was still pressed to the altered warrior's chest. The Ultramarine's ribs had pushed through his breastplate, forming a crude exoskeleton that squirmed and twisted. 'This is a great honour.'

There was agitated movement in the corner of his vision. Marduk looked into the shadows with a smile.

'The Dwellers Beyond await you,' he said. 'Can you feel them? They are close.'

The Ultramarine cried out again. He was unable to form coherent words his tongue had become a grotesque lolling slug-like lump covered in hundreds of fleshy protuberances but the sound was undeniably one of horror and agony.

'What blasphemy is this?' roared a voice, suddenly loud and bold within the chamber.

Burias gave a low warning growl in the back of his throat, and Marduk removed his hand sharply from the Ultramarine's chest. Ceramite boots echoed upon the deck. Marduk stood and turned to face them.

Bel Ashared, flanked by four company veterans, was stalking towards him. Blood-matted furs hung from his broad shoulders. They swung from side to side with each determined, enraged step that he took. His face was hidden within his helm, but his anger was a seething, raging, palpable thing.

Marduk lifted his head high, undaunted. His master loomed over him, an intimidating, glowering presence. The slanted lenses of his visor gleamed with a hellish inner light.

'Only those with closed minds would see this as blasphemy,' Marduk shrugged.

The hulking captain struck him, and the blow dropped him to one knee. It took Marduk a moment to recover from the force of it.

When he did, Bel Ashared was staring down at the twisted, broken figure of the Ultramarine. This once proud warrior of the XIII Legion, his body now vacated by the energies that had been trying to inhabit it, was slumped lifelessly upon the deck limbs and spine bent at unnatural angles, his entire form twisted into something horrific. It looked somehow even more vile now that the warp-things had fled from its flesh. Acrid vapours rose lazily from the corpse.

Bel Ashared hauled Marduk to his feet, and wrenched his helmet off, but the postulant's eyes burned with defiance and belief. The captain hurled the helm aside and pushed his own visor in close. The steaming breath from his frontal grille washed over Marduk's grinning face.

'Your arrogance and your insolence I could tolerate,' growled Bel Ashared. 'But this is an abomination. This is'

'It is the next stage on our path,' Marduk interrupted him. 'To not use the Dwellers Beyond as a weapon is to hobble ourselves. We must use every advantage we possess, if we are to win the coming war.'

Bel Ashared pulled Marduk into a brutal head-butt, and pain exploded across the postulant's face. He would have fallen, but the captain held him upright. His feet were not even touching the ground.

'You are a foolish child playing with things that you do not understand,' Bel Ashared snarled, his vox-emitters turning his voice into a mechanical growl. 'Where did you learn this madness?'

Bel Ashared head-butted him again, fracturing his skull.

'Tell me!' he demanded.

'Are you jealous that you'd not be able to manage such a feat, my honourable mentor?' Marduk slurred. 'Your mind is as limited as your rigid adherence to your beliefs. You refused to teach me, so I found a teacher who would.'

Again, Bel Ashared slammed his armoured forehead into Marduk's. Pain blossomed across the dazed Word Bearer's skull, shooting through hairline fractures and into his temples, yet still he grinned lopsidedly.

'You lie,' said Bel Ashared. 'None of my warriors would teach you.'

'Perhaps I found a teacher beyond your company,' said Marduk, blood trickling from his nostrils. 'One with far more power than you could ever hope to wield.'

In disgust, Bel Ashared thrust Marduk away, sending him sprawling to the deck.

'The Ultramarine killed Sergeant Dralzir,' said Burias. 'Now he has been avenged. Does it matter how that death was achieved?'

The captain glanced over at Burias and levelled a finger at him.