The bridgecastle loomed overhead, an ebony mace wielded victoriously above the ship’s spire-encrusted spine. Kais glimpsed it again and again through the irregular viewing portals above the causeways, set amongst the distant rafters and buttresses of the inner surface of the hull. Around its base an amalgamation of stone fortresses rose majestically into a single buttressed chapel, steel pendants and icons infesting its multifaceted roof, lowermost walls penetrating the ship’s shell. It rose up from within the Enduring Blade like a blistered melanoma, turrets for singed hair follicles and the angular bridge at its tumorous apex.

He’d wondered what to do after the engines died. He couldn’t raise El’Lusha on the comms — couldn’t really believe that there was anyone friendly left in the universe. He seemed so cut off, so immeasurably enmeshed within the grinding wheels of this confrontation, that nothing else was real. He resolved, mind clouded by anxieties, that alone or not he would attempt to pursue the goals his commanding shas’el had set. So he headed for the bridge.

The chapel’s entrance, accessible only via a bridge that extended across a gulf between an outer and inner strata of the vessel’s segmentation, was a causeway-deathtrap. Its slender crossings were pocked by bullet holes and las-scorches and several dead tau lay in a huddle at its entrance. Kais sprinted past without stopping, his mutilated leg a dull crimson roar in his mind. The snipers, wherever they were, announced themselves in a flurry of ghostly ricochets and squib blasts, too distant for the sound of their firing to betray their positions. The dead shas’las wriggled and shook obscenely as they absorbed the crossfire, not safe from damage even in death. Kais hurdled the butchered pile and landed with a muffled shriek, feeling the abused flesh of his leg tearing as he braced against the impact.

He rolled awkwardly and sprung forwards, sensing rather than seeing the impact craters disappearing behind him, and crawled upright feeling winded and dazed. The chapel swarmed open around him, an impossibly vast space that made him stagger in astonishment. Every pillar was a granite behemoth, ascending with prehistoric grace into the distant shadows of the ceiling, where leering gargoyles and stylised figures hulked and glared. Gargantuan stained-glass lenses fractured the light, daubing primary colours across his dirtied armour. He stood for a moment and basked in the massiveness of it all, insectified in an instant. Again he was a maggot, invading something incomprehensibly huge. How could he hope to topple all of this?

Then he looked around and a group of Space Marines was staring at him.

He lurched away with a cry, mind still fizzing with the shock of the bomb blast and the pain of his leg, melting his thoughts into an ugly hash of impression and details. Their features swam before his eyes:

Glaring yellow vision slits and grey-green helmets.

Domed shoulder guards and grasping segmented gauntlets.

Gunmetal weapons, racked and glaring hungrily.

But there was blood too, and the features didn’t seem to interlink properly. There was something...

He shook his head, wincing, and took a deep breath. When he turned back the image slotted into place with grisly precision and for the second time within as many decs he had to force himself not to gag. It was another massacre, another abattoir zone of gut-churning carnage, but this time not mere frail troopers that had been shredded. Their helmets were cleaved and shattered, eye lenses fragmented and the pulpy flesh beneath drawn out like mollusc meat.

Great gash marks rent the shoulder plates and armour fragments open, brittle edges awash with lubricating fluids and thick pulses of blood, running together in colloidal swirls. Kais found himself running a gloved hand in morbid fascination along one such tear, wondering what manner of blade could have so neatly parted such powerful armour.

There was no sign of a culprit, only a shredded perimeter of bolter craters, plasma-scorched metal and smoothed puddles of solidified melta-damage to attest to these abstract chunks of armour and flesh ever having lived.

Kais swallowed hard and let his eyes wander upwards to the red carpeted staircase that rose from the airy centre of the chapel. Somewhere above this bloody grotto was the bridge.

He looked back down at the fleshy detritus and stooped to pick something up.

Delpheus, sprawled on the deck, gnashed his teeth together and fought to stay conscious. It was happening. It was all happening. The masked fiend, inverted. All coming true.

Bolter fire hammered at the air, a furious staccato making his ears ache. Phosphorescent light blossoms capered across his eyesight, amorphous puddles of purple and blue left hanging nebulously in their wake.

Something screamed. He felt his first heart, punctured cleanly with a single razor-sharp blow, palpitating faintly and beginning to die. He expelled a gurgled lungful of air and was unsurprised to taste a thick syrup of blood and bile pooling from his mouth.

“A...” His voice was a lugubrious swamp croak, bubbling pathetically. He spat a gobbet of filth and tried again. “A... Ardias...”

Something blurred above his head, a crackling haze of form and light, rocketing across his vision with a hyena’s giggle. Bolter fire chased it and it was gone, a scampering shape swallowed by the shadows. Nothing he was seeing made any sense.

“What’s...” he mumbled, brain too detached to operate. He wanted information, wanted to cry out for a weapon so he could help his comrades fight back this... this...

What is it?

His first heart died by degrees, contractions diminishing in strength until it perished with a final spasm, its artificial counterpart accelerating its pulse to compensate. The overburdened organ’s hammering exertions made his head pound and his eyes ache, every throb tightening his blood vessels with a percussive roar. His legs wouldn’t work. He couldn’t even feel them.

He’d lost his gun in a slick of oily blood spill, lurching around when the... When the whatever-it-was had ripped from the wall hungrily.

“Ardias?” he tried again, voice weak. “Captain?”

More bolter fire. More death. Another scream as another shape blurred past. It was all happening in another world to someone else, as abstract as a cloud formation and just as unthreatening. He almost laughed.

A Space Marine helmet, lacerated head rattling inside, tumbled past him on the deck. Somewhere a plasma gun foomed breathlessly, destructive energy orb roaring its impact into the air. Delpheus blinked agonised tears out of his eyes.

A pair of sky-blue pillars stomped heavily from the pain haze beside him, cold hands cupping his head with a tenderness belying their brittle form. Captain Ardias glared down at him, concern etched incongruously on his grizzled face. He sounded choked.

“Delpheus? There’s help on its way. You’ll be fine.”

Delpheus smiled through the blood slick, hearing the concern in his captain’s voice. Ardias was a terrible liar.

“I was right...” he gurgled.

“You were right. We’re needed.”

Ardias looked away with a growl, bolt pistol tracking something across the periphery of Delpheus’s vision. It screamed and disappeared in a gout of ichor and light. And then there was a voice in Delpheus’s mind.

Twisting, probing. It was a cruel, venomous thing: slicing through his weakened defences and sinking claws of shimmering empyrean into his brain, ripping and stabbing. Playing him like a puppet.

“Nnnn...” he gurgled, fighting it. The look in Ardias’s eyes told him: You’ll be dead soon.

The thought fortress in his mind fell, once-impregnable walls sundered. The other mind, wherever it was, surged inwards, gripping at his lungs and larynx and manipulating his tongue.