'Aye,' agreed Honsou, marching towards the Imperial Fists as the Iron Warriors spread out to surround them, weapons raised.

A stillness fell as the ancient foes faced one another in the glare of the burning citadel and a massive shadow fell across the square as the Pater Mortis strode from the ruins.

A warrior stepped from the ring of Space Marines and removed his helmet. Honsou could feel the hatred this warrior had for him as he spat, 'I am Brother-Captain Eshara of the Imperial Fists, proud son of Rogal Dorn, soldier of the Emperor and scourge of deviants. Face me and die, traitor.'

The Warsmith faced Eshara and Honsou grinned as he saw the effect his presence had upon the Space Marine. As the captain's face twisted in sudden pain, the Warsmith leapt forward, his mighty axe sweeping down to cleave Eshara in two.

Eshara crossed his swords above his head, blocking the blow, the impact driving him to his knees. He grunted and spun low, slashing a blade across the Warsmith's flank. Black blood gouted from the wound. The Warsmith smashed his fist against Eshara's chest, cracking his breastplate open.

As Eshara fell, the Imperial Fists charged, the name of Rogal Dorn on their lips.

Gunfire erupted from the Iron Warriors, cutting them down as battle was joined.

But it was an unequal struggle and though the Imperial Fists fought hard, the outcome was never in doubt.

Honsou drove his sword through an Imperial Fist, watching in amazement as Eshara groggily rose to his feet, coughing thick wads of blood. The Warsmith roared and hammered his axe down upon Eshara's shoulder guard, cleaving him from collarbone to pelvis, the blade shearing through his armour like paper.

Eshara crumpled, but weakly raised his head as the Warsmith sheathed his massive axe and stooped to lift him from the ground.

'Know this, son of Dorn,' hissed the Warsmith. 'I will gorge myself on your gene-seed and I shall make you and all your kind extinct.'

The Warsmith lifted Eshara's dying body to his head where there was a monstrous cracking, sucking noise. Blood splashed the steaming ground at the Warsmith's feet and he bellowed in orgiastic pleasure, dropping Eshara's mutilated corpse.

Even Honsou was shocked as he saw the Space Marine's entire chest cavity had been bitten through, the organs within sucked from his body and devoured by the Warsmith.

Honsou dismissed the incident from his mind and set off after the Warsmith as he charged through the gateway that led into the mountains and their ultimate goal.

Leonid hammered his rifle butt through the glass of an incubation tank and stood back as the amniotic fluid spilled out along with its foetal cargo. He used brute force because his lasgun's power cell had long since drained. He moved onto the next capsule, staring in awed wonder at the sheer scale of the cavern stretching before him. Its end was lost in shadows, the vastness broken up by wide avenues of incubation capsules. Thousands of tanks ran in ordered lines into the darkness, their clear surfaces frosted and cold to the touch.

Now Leonid understood the danger inherent in this place. If what Naicin had told them was even partly true, there was enough genetic material stored here to create untold thousands of twisted warriors of Chaos. The very thought of such creations being birthed from here was truly horrifying.

Worker-servitors with shoulder-mounted illuminators were spots of light in the darkness, moving silently through the echoing cavern as they tended to their biological charges. Hundreds of his soldiers rampaged through the cavern, shooting, burning and smashing everything they could. But Leonid knew it was a hopeless task, the sheer scale of the facility here would defeat them. There was no way they could destroy it all before the Iron Warriors came to kill them.

But they would try. It was all they had left.

Honsou and the Iron Warriors followed the Warsmith as he sped down through the corridors beneath the mountains. There was a desperate hunger to the Warsmith now, like a fleshhound with the scent of blood in its jaws. His body pulsed like a heart in the throes of a massive seizure, as though containing a whirlwind of potentiality that strained to be born.

Ahead, Honsou heard sounds of destruction and knew they were approaching the prize the citadel had jealously guarded. As the passageway widened and levelled out, he saw a massive set of gold doors, green lightning dancing across their surfaces, and a cavern beyond.

Shouts and the sound of shattering glass quickly turned to cries of alarm as the humans saw the charging Iron Warriors. A few brave souls attempted to stand before the Warsmith, but quickly crumpled as he neared them, screaming and spasming in agony.

The Iron Warriors plunged into the cavern, gunfire echoing from the walls as they slaughtered the last defenders of the citadel.

The Warsmith halted beside a shattered incubation capsule and dragged out a limp rag of pink flesh, sodden and only vaguely humanoid. The Warsmith feasted upon the genetic host matter, feeding on the soft, boneless tissue and Honsou felt his skin crawl as though a powerful electric charge was building.

The Warsmith moved to the next capsule and fed once more. He turned to Honsou and rasped, 'Finish them all.'

Leonid worked his way back to the cavern's entrance, his power sword gripped tightly and his face set with grim resolve. There was no more they could do here to make a difference and he felt their failure as a bitter weight in the pit of his stomach. If this was to be their end, they would meet it head on, not hiding. His men had no ammunition left and the sounds of battle around him were brutal and short lived.

He and perhaps fifty soldiers followed a revolting sucking, guzzling noise, determined to sell their lives as dearly as possible now that the end was inevitable.

Leonid rounded a corner of dripping capsules and recoiled at the sight before him.

The Warsmith cast his arms to the cavern roof as he felt the power of the gene-seed coursing through him, though he realised that its power was largely symbolic. He had succeeded and the power of the dark gods poured into their chosen vessel, ripping him from his mortal flesh and gifting him with the boon of immortality.

His armour sloughed from his body, its material form no longer appropriate for such a magnificent creature of Chaos. A spiralling vortex of dark energy surrounded him, cracks exploding in the rockcrete floor as power flared from his limbs.

As the psychic energy built up, the Warsmith swelled, roaring as he felt his power magnifying.

His chest hiked convulsively as the might of Chaos poured through him. He was aware of his warriors and the Imperial soldiers, but he needed all his concentration to direct the incomprehensible energies that remoulded his new daemonic flesh.

The Warsmith roared in ecstasy and agony as unprecedented power engulfed him. His body swelled hugely, bloated by the maelstrom of energy that cycloned within.

A ridged horn burst from his forehead in a welter of blood and tissue. The mottled spike writhed like a living thing, swelling and wrapping itself around his head. His skin darkened, taking on a loathsome scaled texture. His spine cracked and he screamed as it elongated and thickened, roaring as the shadows at his back solidified and the dark wings spread wide and flapped powerfully.

The newly elevated Daemon Prince was lifted from the ground, hanging suspended before the horrified witnesses to its birth as the last of the psychic energy drained from its body in an explosive wash of power.

Though he knew it meant death, Leonid raced towards the floating daemon, his sword raised to strike it down.