Pressure ripped at his robes. The explosion's electromagnetic pulse sent his implants haywire. For a moment, he lay stunned, machine senses offline, human senses numbed.

He pulled himself up with the help of his servo-arms.

The Sicaran was a blackened husk. The top half had been completely obliterated. The bottom half was cupped like a palm holding a guttering fire.

'So perish all who turn the gifts of the Machine-God against the Omnissiah,' intoned the myrmidon.

Cawl glanced up at them. He ran down the corridor, pleasantly surprised at the extra strength his power armour gave him. But he was too slow to catch his charges. The legionaries had been sheltering at a junction. The flash and rattle of weapons receded down the corridor to the left, leading to one of the vast cavern-fields. The cyborgs' in sight was immune to the overload that had floored Cawl, and they had already moved on. He looked around helplessly. Dead Night Lords and Word Bearers were scattered about the decking. Their colours were different to one another, but the grisly nature of the trophies they wore made them brothers of a sort, and set them apart from legionaries as Cawl knew them.

There was something else there, a ragged corpse in black with the stature of a standard human.

Sensing something amiss, Cawl approached it gingerly, priming his serpenta. He pointed the weapon at the figure, though he had no reason to believe it alive.

The figure had been felled by an access panel whose workings he seemed to have been in the process of subverting with a portable cogitation unit. He was face down, hidden by his robes, one pale hand stretched out to the side of him.

Cawl's Mechanicum power armour allowed him to roll the augmented figure over with his foot.

The corpse was a tech-adept. The augmetics told Cawl that But his robes were black, a colour no forge world wore, and the sacred symbology of the Cult Mechanicus was perverted. Around the machina opus stitched over his heart were eight arrows, like those of a compass rose, and the skull contained within the cogs wore a daemonic grimace.

Cawl looked more closely. There were strange malformations in the adept's flesh that augmentation could not explain. His jaw line was fringed with bony excrescence that had grown over some of the metal of his implanted voxmitter. Upon his head. Upon his head… Something moved upon his head, wet and sinuous.

Gripped with foreboding, Cawl leaned in to see what nestled between the cabling across the adept's scalp.

As Cawl bent down, the adept's eyes snapped open. They were like no eyes Cawl had ever seen. Vertical slit pupils split irises striated with purple and gold.

Instinctively, Cawl fired his volkite into the man's face. Metal and flesh vanished beneath the torrent of energy, exploding into steam. He shut off his gun when the body ignited. Dying augmetics sent the headless man's limbs into a maniac dance.