The attack was aimed at Decius's shoulder, poised to penetrate his armour and cut his primary heart in two, but the Astartes moved. Decius succeeded in avoiding a killing impact, but still his reflexes were not enough to save him from a slash that cut his ceramite armour wide open. He fell down, turning and yelling as he did so. Pain erupted along his nerves as his power fist malfunctioned where the knife had torn into it.

His eyes widened as he saw rust and corrosion worming out across the damaged metals, a time-lapse pict of decay made real. Decius felt agony chewing at his veins and marrow, and sweat burst out all over him as his implanted organs went into overdrive to stem the tide of secondary infections.

Corruption! He could already see his skin distending and blistering where the plague knife had cut him. Decius's gut churned as the invisible phages that swarmed across Grulgor's blade massed inside him. He fought back bile as the twisted Death Guard loomed over him.

'No man can outlive entropy!' spat Gralgor. The mark of the Great Destroyer claims everything!'

His joints swelled and became inflamed and painful. With monumental effort, Decius swung up

his chainsword and hefted it. The corpulent mutant rocked back, out of range if the young Astartes tried to slash at him with it, but instead Decius brought it down hard across his arm, just below the elbow joint. With a scream of hate, the young Astartes severed his own limb, letting the plague-ravaged flesh and crumbling metal of his gauntlet fall away.

His vision fogged, the youth's body was at its limits fighting infection and injury, and it could not support his consciousness. Decius's eyes fluttered as his body went slack and dormant.

Grulgor snorted and spat out a gobbet of acid phlegm before raising his plague knife again over Decius's unmoving body. Heavy bolt shells tore into his back and ripped away curls of dead flesh, knocking him off-balance before he could deliver the killing blow.

GARRO'S AIM WAS exact, and it sent the Grulgor-thing stumbling, back towards the hull wall and away from Decius. Nathaniel wanted to look to the boy, to be sure that he was still alive, but his old rival was only wounded and from what Garro could see these reanimated men healed as fast as he could hurt them. All around him, Voyen, Hakur and the others were caught in their own small battles. He pushed questions of the why from his mind and concentrated on the how - how can I kill him?

Grulgor spun around and let loose a gargling roar, emerald-tinted blood trailing from him in a wet arc. Garro's old foe snatched at him, the plague knife and his cancerous fingers slicing through the air and missing. Garro fired again and heard the hollow clack as his bolter ran dry. Without missing a beat, he let the gun drop and took Libertas in a two-handed grip.

'I knew this moment would come,' gurgled the mutant. 'I would not be denied it. My enmity for you is beyond death!'

Garro grimaced in return. 'You have always been a braggart and a fool, Ignatius. On the field of battle you served a purpose, but now, you are an abomination! You are everything the Astartes stand against, the antithesis of the Death Guard.'

Grulgor spat again and made a clumsy, furious pass that Garro parried with quick replies. 'Nathaniel! So blind! I am the harbinger of the future, you pathetic wretch!' He pounded a crooked-fingered fist on the rusted armour over his breast. The warp's touch is the way forward. If you were not so blinkered and mawkish, you would see it! The powers that exist out there dwarf the might of your Emperor!' Grulgor pointed his knife at the throbbing crimson light beyond the starship. 'We will be deathless and eternal!'

'No/ said Garro, and took the sword to him. Libertas swung low and cut into Gralgor's fleshy, fish-belly white gut, and tore. Nathaniel's blade met diseased meat and to his alarm, it sank inwards.

Instead of cutting through pliant skin, the sword became enveloped in a doughy morass that drew on it like quicksand. Flickers of power from the blade sparked and died. Grulgor rumbled with amusement and puffed out his barrel chest, sucking the weapon into his body. 'There is no victory here for you,' he hissed, 'only contagion and lingering agony. I'll make this ship an offering of screaming meat-'

'Enough!' Garro could not draw the sword out. Instead, he ran it through. With all his might, the battle-captain rode the blade down and carved it out across the mutant's abdomen, forcing a full charge through the crystalline matrix steel. He opened

Grulgor with an angry snarl and Libertas at last came free.

Fatty ropes of serpentine intestine writhed and fell from the cut in loops across the wet decking. The former Astartes wailed and struggled to catch them in his hands, stuffing them back into the maw of his belly. Garro rocked back, the putrid gas from inside the bloated body making his eyes stream and throat clog.

The Eisensteiris deck shivered beneath his feet and for a split-second the captain's attention was taken by a rolling flash of chain lightning that surged around the flanks of the frigate.

He heard Hakur shouting. 'The Geller Field! It's failing!'

Garro ignored Grulgor's hooting laughter as glimmering motes of firelight began to form in the heavy air over their heads. He thought of the homunculus plague bearers and the slashing razor-disc predators from the navis sanctorum. If they came to bolster Grulgor and his changed army, the tide would turn against Garro's men. He could sense the engagement slipping away from him, the certain prediction of the battle's play hard in his thoughts just as it had been on the jorgall bottle-world and a hundred times before. He had only moments before the fight was lost to him.

Grulgor saw the expression on his face and laughed. The mutant Astartes spread his hands to the roiling, churning hell-light outside as a willing supplicant, basking in the alien energies. Outside, the membrane of artificial force that separated the frigate from the madness was disintegrating. Already weakened by the incursion of the pestilent touch that made Grulgor live and the breaches of the warp-beasts, the Geller Field unravelled in flares of exotic radiation, layer upon layer peeling back as if it were flesh flensed from bone.

Garro shouted into his vox, a desperate gambit coming to the fore of his thoughts. 'Qruze!' he cried, 'Heed me! Get us out of the warp, crash reversion! MowV

Over the clash of the skirmish and the buzzing interference, he heard raised voices in the background, the bridge crew reacting with shock at his demands. The Luna Wolf was wary. 'Garro, say again?'

'Drop out of the immaterium! These intruders, the warp must be sustaining them somehow! If we stay here we'll lose the ship!'

'We can't revert!' It was Vought, her words laced with panic. We have no idea where we are, we could emerge inside a star or-'

'Do it!' The order was a thunderous roar.

'Captain, aye/ Qruze did not hesitate. 'Brace yourself!'

'No, no, no!' Grulgor pounded across the deck towards him, raising his blade. You will not deny me my satisfaction! I will see you dead, Garro! I will outlive you!'

The battle-captain brought up his sword and batted Grulgor away. 'Be gone, you stinking freak! Back to your hell and choke on it!'

Through the armoured window slits, a flurry of brilliant blue-white discharges signalled the creation of a warp gate, and the frigate dropped through the screaming maw and back into the realm of real space. Grulgor and his freakish kindred bawled a chorus of agony and frenzy, and dissipated.

Garro saw it with his own eyes and still he could not explain it. He witnessed a roaring, shimmering phantom tear itself from the meat sack of a body, drawn up and away as if it were a leaf caught in a hurricane, and for an instant he saw the shapes of both