'Do not speak another word, novitiate. I will judge your complicity in this sacrilege once the mission is complete.'

Burias bowed his head in deference and backed away.

Bel Ashared stepped carefully around the corpse. Its flesh was rotting at an accelerated rate, liquefying and sloughing from the contorted bones.

Marduk was rising, his face slick with his own blood. Bel Ashared lifted him back to his feet and slammed one of his gauntleted fists into his face, splintering teeth and breaking his nose. The force of the blow put Marduk straight back down.

'To become one with the forces of the empyrean is something honoured and revered,' said Bel Ashared. 'It is a holy union. To force it on an unbeliever is abhorrent! An affront! Sacrilege. Such is the decree of Kor Phaeron himself.'

'Decrees can be wrong,' said Marduk, spitting blood and shards of tooth. 'The Emperor's lapdogs will find that out soon enough. Once even you worshipped the Emperor as a god.'

'The Legion has seen the folly of its former ways,' said Bel Ashared.

'And it will once again,' said Marduk.

'Enough!' Bel Ashared roared. 'How did you do this? Tell me!'

'You could never master it,' sneered Marduk. 'You're pathetic. You want so badly to be ushered into the Gal Vorbak. It will never happen. You're too unwilling to open yourself up to the Dwellers Beyond. The lack of knowing, the uncertainty it terrifies you.'

The silence of the other assembled Word Bearers was absolute. Bel Ashared laughed, almost in disbelief.

'I do not have time for this,' he said. 'I will not be shamed in this manner. Hold him.'

Two of his warriors stepped forward, grabbing Marduk roughly between them, and Bel Ashared unslung his axe. Insulated cabling linked the weapon to his armour's power source; its head was fashioned in the likeness of a leering hell-creature, and its crescent blade hummed as it came to life in his hand.

'By your actions have you damned yourself, postulant,' said Bel Ashared. 'Kneel and accept your fate.'

Marduk spat at the captain's feet.

'The knowledge of your limitations has blinded you with bitterness, Bel Ashared,' said Marduk. 'I pity you. You are cursed. You know your limitations, but you cannot accept them. You are doomed to mediocrity, and that knowledge eats away at you like a cancer.'

'Kneel,' the captain growled.

Marduk was forced to his knees. Bel Ashared's axe blade crackled. The scorched ozone stink was strong.

'This is a path that I had hoped to avoid,' said Marduk, glaring up at his appointed mentor, his eyes narrowed venomously. Bel Ashared's emerald visors, set deep in his grim Mark VI helm, glowered down at him. 'But you leave me no option.'

'You brought this upon yourself,' said Bel Ashared. 'It is time for you to swim the Sea of Souls, and be damned for all eternity.'

'No,' said Marduk. 'The time is yours.'

The shadows coiled, knowing what was to come.

Dhar'khor'del'mesh Arak'sho'del'mesh Drak'shal'more'del'mesh.

The voice stabbed into Marduk's mind like a needle. Fresh blood trickled from his nose, and his eyes turned black.

'Dhar'khor'del'mesh Arak'sho'del'mesh Drak'shal'more'del'mesh,' he said. The words made his mouth bleed.

Hidden runes carved inside Bel Ashared's armour flared, and then in one sudden, violent twist of unreality, he was turned inside out.

Kor Phaeron pursed his blackened lips. 'With no instruction, you were able to do this?' he asked.

'Yes,' said Marduk, still on his knees. 'The Primordial Truth itself guided me.'

Kor Phaeron turned away, staring out through the view portal at Calth. The uncomfortable tingling in Marduk's flesh lessened somewhat in response.

Marduk waited for Kor Phaeron to speak, knowing that his fate would be decided here and now.

'Bel Ashared was a fine soldier,' said Kor Phaeron, finally. 'But he was limited, perhaps in ways that you are not.'

A ghost of smile crept onto Marduk's face. 'You will teach me, then?' he said.

Kor Phaeron turned back towards Marduk. Impatient energy played across his skin, lighting it from within.

'Jarulek spoke highly of you,' he muttered. 'He tells me that you acquitted yourself well during the Purge.'

'I did what was asked of me,' said Marduk. He raised a hand to his throat where a knot of old scars encircled his flesh like a necklace. 'I did my duty.'

'And what did you feel as you killed your own kin?'

'They were not my kin.'

'They were of the XVII and the blood of Lorgar ran in their veins, as it does in yours,' said Kor Phaeron, though Marduk felt that the Dark Cardinal was pleased with his answer.

'They were not of Colchis,' said Marduk. 'They were not my kin. It felt... good to kill them.'

'Why?' said Kor Phaeron, leaning forwards like a predator. His eyes glittered.

'Their deaths were significant. They had meaning. There was power in their sacrifice.'

'Ah. "Power" once again.'

'Am I wrong, master?' said Marduk.

'No. Even the most primitive cultures instinctively understand that there is power in death. A child ails with fever? His parents sacrifice a feed-beast and beg whatever god they pray to for his recovery. They sacrifice to the Primordial Truth, no matter what name they give to their bloodthirsty deities.' Kor Phaeron took on an evangelical tone, as he might be delivering one of his potent sermons to the Legion. 'But some things require larger sacrifices, something more significant. Famine and plague ravage your cities? Your enemies march upon your walls with murder in their hearts? The sacrifice of a lowly bovid will not suffice then. It is in the human psyche to understand this. Without needing to be told, we all know that some deaths are intrinsically more meaningful than others. The death of a man is more powerful than the death of a beast and as men are raised above beasts, so too are the Legiones Astartes raised above men. It follows that their sacrifice has a subsequently higher significance.'

Kor Phaeron turned.

'And much more can be achieved with the power that blossoms from such a sacrifice.'

Marduk's gaze drifted towards the vision of Calth beyond the station's viewscreens.

'What could be achieved with the death of a world?' Marduk wondered out loud.

'What indeed.'

'And the death of a primarch?' whispered Marduk. 'I see the truth of it. They are the next step.'

'Yes,' said Kor Phaeron, 'they are. Ferrus Manus will not be the last.'

A klaxon blared, and Marduk saw Kor Phaeron's thin lips part in an unpleasant, grimacing smile. He had a fevered, hungry look in his eyes.

'Teleport signature,' said one of the dark magi hunched over a console. 'We are boarded.'

'Guilliman,' hissed Kor Phaeron. 'At last.'

'He's here?' said Marduk. 'You knew he would come?'

Filthy light gathered around Kor Phaeron, and Marduk could hear the gibbering beasts of the empyrean whispers and cries that crowded in through every speaker, vox-link and console on the station.

Kor Phaeron seemed to grow in stature, coiled in darkness.

'This is my time,' he said, rising up from the deck, black vapours oozing from his eyes and mouth. Unholy energies played across his splayed, skeletal fingers, and the currents of the warp washed over Marduk like a drowning tide, emanating from the Dark Cardinal in waves.

'Today is a great day, my sons,' said Kor Phaeron, his voice raised to be heard over the infernal cacophony. 'Today we will see a primarch brought to his knees. He comes to us, drawn like a moth to the flame, not realising that the flame will be his ending.'

Marduk made to rise, but felt a hand upon his shoulder, holding him in place. The grip was strong; it was that of Sorot Tchure. He had a blade in his hand.

An athame.

'My lord?' said Tchure. 'The postulant?'

Kor Phaeron was like an angel of darkness, haloed in terror. He looked down at Marduk. There was no mercy in his expression, merely a vicious hunger and yearning. His eyes had turned completely the deepest black of the dark spaces between the stars.

'He has their favour,' rumbled Kor Phaeron. 'This is the source of all power. Release him.'

Tchure's blade disappeared, and Marduk was raised to his feet. He gaped up at Kor Phaeron, bathing in his unholy majesty.

'Whatever power I have is yours,' he said, eyes shining with devotion.

Kor Phaeron drifted down towards him, dragging the darkness in his wake. Marduk bowed his head and dropped to one knee, this time as a devotee rather than a prisoner. He felt the heat radiating from Kor Phaeron's body as he came close, and he flinched as a burning hand was placed upon his head.

Marduk struggled not to cry out. His skin blistered under the unholy benediction.

'Do not attempt to use your new talents in this battle, postulant,' Kor Phaeron hissed. 'The power of the empyrean flows strong. I will have all of it.'

'It will be as you wish, my lord,' said Marduk.

'You are blessed, child,' said Kor Phaeron. 'Today, you will witness an act that will echo down through the ages. Today you will witness true greatness.'

Kor Phaeron released Marduk and stood resplendent as the warriors of the Legion readied themselves for battle around him.

'Today, my sons, you will witness the death of Roboute Guilliman,' declared Kor Phaeron, his voice resonant. 'Or perhaps,' he added, slyly, 'something greater still...'

A bolter was pressed into Marduk's hands without ceremony.

'Be ready, lad,' said Sorot Tchure. 'They come.'

Marduk cast the bolter aside, its magazine spent. He picked up a heavier double-barrelled weapon from the dead grasp of a fallen veteran and squeezed the trigger, unleashing a torrent of fire into the charging horde of Ultramarines as they stormed the master control room.

The Ultramarines were dying, but the Word Bearers were dying faster.

Bodies lay scattered across the deck. The giant leading the Ultramarines was like unto an unstoppable force of nature.

The hated primarch. Guilliman.

Nothing could stand in his path. He swatted Word Bearers aside, sending Gal Vorbak and legionaries flying. A grim warrior in a red helm fought at the giant's side, wielding an exotic longsword that sliced through armour like wet fabric. Some sort of champion, most likely.

Marduk dropped one Ultramarine with a well-aimed bolt round, and sent another reeling, his armour shredded. He tried to gun down the red-helmeted swordsman, but another warrior was caught in the crossfire ceramite chunks were blasted from his armour, before he was cut in two by the scything arm-claw of one of the Gal Vorbak. The clash of armoured bodies as the Ultra-marines slammed into the Word Bearers was almost deafening.

Kor Phaeron flew at Guilliman, black energies trailing in his wake.

Marduk had no chainsword, and his athame had been taken from him. He stepped backwards, trying to keep his distance from the rush of the enemy. The combi-bolter bucked like a wild beast in his hands; he fought to keep its aim down.

There was a flash through the press of bodies and a blade cleaved his weapon in two in a shower of sparks. The red-helmed swordsman made to lunge for him, but the surging melee kept them apart, and moments later the disarmed postulant was evidently forgotten amidst the throng.

Marduk cast his ruined weapon aside. There was a blinding flash of plasma and an Ultramarine's chest was burned out not three paces away Marduk plucked a power maul from the dying warrior's hands and set about with it. Chainswords were built to rend flesh, not power armour, but a power maul was more effective against Legion plate, crushing ceramite and bone with equal vigour.

Beyond them, Marduk could see the hunched figure of Kor Phaeron, robed in shadowlight, standing triumphantly over the downed giant, Guilliman.

Marduk saw Kor Phaeron's blade at the giant's throat, and his bitter hearts sang.

Victory was at hand.

The postulant cried out in elation, swinging his maul left and right. He would be a righteous agent of the Word until the end of time. The heavens themselves would Something changed. The currents of the warp fluctuated for a moment, before a cry of anguish went up.

The Dark Cardinal had fallen.

Marduk shrieked, staving in the skull of an Ultramarines officer with a dozen frenzied blows.

The Dark Cardinal had fallen.

There was a scramble of armoured bodies, a frantic press which obscured Marduk's view of the scene. Beyond, fires were breaking out across the control deck. Alarms sounded with renewed vigour.

In a single moment of horror, Marduk caught sight of Kor Phaeron again.

He was being dragged across the deck, pulled in several directions by Ultramarines and Word Bearers alike, who screamed and spat and struck at each other as they heaved and tugged.

Both sides wanted to claim the body.

'Help us, damn you!' Sorot Tchure cried over the din. Half of the veteran's face was missing, exposing bone and teeth. Marduk did as he was bidden, his eyes wide in shock.

This was not how it was meant to be. Guilliman should be dead. This should be their moment of triumph. Marduk skidded on the deck plates, smeared with Kor Phaeron's dark blood.

Together with the last remaining members of the Gal Vorbak, Marduk helped to bear the shattered body of Kor Phaeron from the burning master control room.

How the Master of the Faith still drew breath was beyond him. His chest was a mangled ruin. The gaping hole in his breastplate and fused ribcage exposed a pulsing crater of ruined flesh. Black, foul-smelling fluid covered his armour and bubbled from his lips, while wisps of warp-shadow streamed from his eyes, mouth and nose.