Fundare, also from Erastus's squad, doused a squealing, shrieking plague-thing, its malformed body sporting only a single eye and a single horn, its bloated gut a mass of suppurating pustules. The abomination was sent screaming across the hall in a blaze of fire, gouts of blackening orange flame flying from it and igniting the filthy robes and clothes of other turncoat acolytes and troopers.

Yet another of the relentless Nurgle Marines loomed large before Gdolkin. The Iron-Father let out an involuntary gasp. Even he had seen few sights as appalling as this one. The Lord of Decay might grant his servants a repulsive aspect, but he did not so readily accompany such gifts with mutation. However, this was not the case of this debased Plague Marine. The Nurgle worshipper's head had changed into that of a facet-eyed fly, a tubular pink tongue as long as the haft of Gdolkin's power axe darting from an obscene insect proboscis.

How could a Space Marine brother of one of the First Founding Chapters of the Adeptus Astartes, who had been implanted with the gene-seed the immortal Emperor himself had engineered, have become as corrupted as this?

Gdolkin gave vent to his anger and horror with a vehement cry of, 'Die, plague spawn!' cutting down the fly-headed monstrosity with repeated blows of his crackling, energy-sheathed axe, before the vile thing even had time to raise its own corrupted bolt pistol.

And then they were through and the tech-guard were running past them, up the spiralling iron stairs to the top of the chamber's elevated central control tower. A flailing heretic fell past Gdolkin, screaming, as Captain Thrask and his men neutralised the resistance awaiting them at the top of the iron-latticed tower.

And yet still the plague devotees continued to throw themselves onto the Iron Hands' guns. The pox-ridden servants' faith in Father Nurgle had made them bold: bold and stupid, and insensitive to pain. They ran readily to their deaths on the end of the Iron Hands' chainswords, sacrificing great numbers simply to further the Plague Lord's perverse plan.

A yowling beast, all clawing talons and gaping intestinal abscesses, flung itself at Gdolkin. He kicked out at the daemon-creature from the step from which he was defending the control turret, his bionically assisted kick shattering its jaw and spraying deformed fang, black bile and scrofulous flesh into the battling mass behind.

The plaguebearer looked at the Iron-Father, its single jaundiced eye fixing him with a blood-shot stare of brooding hatred. Then, with a suddenness of speed that alarmed even the fast-reacting Space Marine, it lashed out with the raking claws of its talons. Claws like steel needles tore through the ceramite greaves of Gdolkin's left leg and snagged a piston part of the Iron-Father's artificial leg. He was immediately aware of a drop in effectiveness in that limb that was echoed by the runes appearing in the red glow of his heads-up visor display.

That was all it took. Bellowing with rage, Gdolkin turned his bolt pistol on the plague-beast. The scene of carnage was lit by the strobing muzzle-flash of the pistol firing as the unreal ectoplasmic fabric of the daemon was shredded by the exploding bolter shells. In seconds all that was left of the monster was a rapidly dissolving, bubbling mess of green slime dripping through the gaps in the grilled floor of the chamber.