The tech-priest dropped to the floor. Smoke poured from his ears as his remaining flesh cooked. Silence spread. The babble of voices and the hum of signals vanished. In her cradle the lone servitor remained, twitching in place, shouting the only thing her slowly melting brain could hear.

‘Samus! Samus is here! Samus is the man beside you!’

Darkness bubbled up out of the hull along the Phalanx’s spine. Swarms of creatures pulled their wings from the dark and launched into the vacuum. Close-defence turrets opened up. Las-bolts blasted ghost flesh to slime. One of the Phalanx’s escorts became a scream of detonating void shields and splintering armour.

Su-Kassen was shouting as the darkness poured into the chamber she and Dorn had been waiting in. Coiling strands of night flowed through the open doors. Beyond, she had a glimpse of a dark shape, like the shadow of a vast wolf cast against a wall by an inferno. It was growing, stretching. The Huscarls around her and Dorn were firing. She could smell ozone and blood, spun sugar and sulphur. The shadow of the wolf beyond the door turned its head as she looked at it. Red eyes met hers. She raised her shot-pistol and pulled the trigger. A cloud of metal fragments tore into the space between her and the shadows and became flares of light.

A shape detached from the spreading dark. It grew as it moved, sheathing itself in bloody meat and bone as it ran. Su-Kassen fired again, and again, punching the dog-like thing backwards.

Dorn moved past her, a golden blur against the shadow. She had never seen him in battle. They had conducted war together for over half a decade, but it had always been remote, his genius and nature expressed in insight, in cold logic and plans that unfolded at a distance. She had never seen him fight in front of her. Not so close that she felt the rush of his passing. He did not have Storm’s Teeth. The great chainsword that he bore in battle was in his chambers. But he was still a primarch, a weapon that needed no other.

His first blow hit the daemon hound and exploded its skull and body down to his hind legs. The wall of shadow drew back, rising like a cresting wave as it touched the ceiling. Dorn had his bolter in his hands. Shots punched into the oily matter. It rushed forwards.

‘No!’ Su-Kassen went forwards, firing her pistol. Dorn stood his ground, a lone figure, face set, lit by muzzle flash. The tide coiled above them.

Dorn fired another burst and turned to one of the still-open exits from the chamber.