The final battle for Khalan-Ghol was about to begin.

'We cannot stop this attack,' said Onyx, watching as the Titans of Berossus began their inexorable advance up the ramp to the fortress. Though still many kilometres away from the top, the scale of their daemonic majesty was magnificent. 'Berossus will sweep us away in a storm of iron and blood.'

Honsou said nothing, the ghost of a smile twitching at the corner of his mouth. He too watched the huge force coming to destroy them. Hundreds of screeching daemonic warriors spun and looped in the sky above phalanxes of weapon-morphing monsters whose flesh seethed and bubbled with mechaorganic circuitry. Scores of howling, spider-limbed daemon engines clanked and churned their way up the ramp, jetting noxious exhaust fumes, the hellish entities bound to their iron bodies eager for slaughter now that they were free of their cages.

Clad in his dented and battered power armour, with a reckless look of battle-hunger creasing his pale features, and sporting a gleaming silver bionic arm in place of the one his former master had gifted him with, Honsou seemed unfazed by their approaching doom.

Onyx was puzzled by this, but had long since realised that the inner workings of Khalan-Ghol's newest master were a mystery to him - the half-breed did not resemble or behave like any of the warsmiths he had served in his aeons of servitude to the masters of this fortress.

'You do not seem overly concerned,' continued Onyx.

'I'm not,' replied Honsou, turning from the cracked ramparts of the topmost bastions of the spire. A hot wind was blowing, tasting of ash and metal. Honsou took a deep breath, at last turning to face his champion.

'Berossus hasn't let me down this far,' said Honsou, staring out at the great tunnel that led into the ramp and, no doubt, beneath his fortress. 'And I hope he won't now. Not at the last.'

'I don't understand.'

'Don't worry, Onyx, I know your concern is for your own essence, not my life, but you don't need to understand. All you need to do is obey me.'

'I am yours to command.'

'Then trust me on this,' grinned Honsou, and looked down to the level below, where smoke and crackling lightning conspired to obscure his own Titans and the masterful works he had prepared for Berossus. He stared up into the featureless white sky and the sun that burned like a black hole above him. 'I have fought the Long War almost as long as Berossus and Toramino and have stratagems of my own.'

'For your sake, I hope so,' said Onyx. 'Even if we manage to stop this attack, there is still the matter of Lord Toramino. His army is yet to be blooded.'

Honsou glanced to the glow of fires and forges beyond those of Berossus's encampments, where Toramino waited, unseen and unknown. Here, at last, Onyx caught a flash of unease.

'He waits for Berossus to grind us and his own warriors to dust before marching in to take Khalan-Ghol and become lord of its ruins.'

'And how will we stop him?'

Honsou laughed. 'One problem at a time, Onyx, one problem at a time.'

The hateful sound of massed artillery fire was muted and distant, though Uriel knew it must be perilously close to be heard this far beneath the mountains. Dust drifted in lazy clouds from the tunnel roof, and fine pebbles skittered and danced upon the floor. The darkness was absolute, even his enhanced vision had difficulty piercing the gloom.

Heat filled the tunnel along with the hot, foetid stink of animals, though these were no animals. They were, or at least had once been, human.

Hundreds of the Unfleshed filed along the fearful passages beneath the mountains, their winding route taking them through echoing crystal chambers, disused manufactorum and up dizzyingly steep stone channels hacked into the rock. Their massive bodies filled the passageways as they led Uriel and the others back towards Khalan-Ghol.

They travelled through dark and secret ways under the mountains, forgotten by all save them, the hidden, abandoned culverts and the lost, forgotten passageways that led towards their fate.

Behind Uriel, Pasanius grunted with effort, his journey made all the harder by virtue of his limb's amputation, but wherever he had encountered difficulty, the Lord of the Unfleshed reached back and lifted him onwards.

The giant creature led the way through the darkness, his huge form easily filling the width of the passage, and were it not for his hunched shoulders and stooped head, he would surely have dashed his skull open on drooping stalactites.

The Lord of the Unfleshed marched with newfound purpose, his long, loping stride setting a fearsome pace through the secret mountain paths. Uriel winced with every step, his breath painful in his single functioning lung and the pain of his cracked collarbone and ribs stabbing into him without the balms of his armour's dispensers to dull them.

Further back, a twisted creature with a withered twin fused to its back carried Leonid, the stunted sibling clutching the grimacing colonel tightly in its embrace. And further back yet came Ardaric Vaanes and his two surviving Space Marine renegades.

When the rapture of the Emperor's coming to life before the Unfleshed had died down, the creatures had embraced Uriel's cause with all the zeal and fervour of a crusade, mustering those who could hunt and fight to join them. It had made Uriel want to weep at the holy joy that infused every one of them and made his deception of them even harder to bear.

As he had gained his feet before the Lord of the Unfleshed, it had beckoned to one of its tribe, and another of the beasts loped towards him. Uriel saw that it was the creature he had fought in the outflow pool, his sword still jammed in its belly.

'Take blade,' said the Lord of the Unfleshed and Uriel nodded, gingerly gripping the hilt of the weapon. He had pulled, muscles straining as he fought the suction of flesh, bracing his feet on the floor of the manufactorum to gain better purchase. The sword was wedged tightly in the beast's body and he was forced to twist the blade to allow it to move. At last, it slid grudgingly from its sheath of flesh, the creature remaining stolidly silent throughout. As it came free, the giant beast moved to join the remainder of its awed brethren.

'Thank you,' said Uriel.

The Unfleshed nodded respectfully and Uriel had felt a glowing ember of hope fan to life in his heart.

But his initial relief and elation at such a turn of events had soon turned sour when he had been reunited with his comrades and Ardaric Vaanes spoke to him.

'They will kill you when they discover you have lied to them,' said the renegade as the Unfleshed had girt themselves for war, gathering crude iron cudgels. Most needed no weapons however, their horrific mutations equipping them for killing without the need for such things.

'Have I?' Uriel had said, guardedly. 'I do the Emperor's work, and so now do they.'

'The Unfleshed?' said Vaanes, aghast. 'You think the Emperor would work through such beasts? Look at them, they're monsters. How can you think that such creatures are capable of being instruments of His will? They are evil!'

'They carry the flesh of the Emperor within them,' snapped Uriel. 'The blood of ancient heroes flows in their veins and I will not fail them.'

'Don't think you can fool me, Ventris,' sneered Vaanes. 'You are no messenger of the Emperor, and I can see in your eyes that you know you're not either.'

'It does not matter what I believe any more,' said Uriel. 'What do you believe?'

'I believe that I was right about you.'

'What does that mean?'

'That I knew you were trouble the moment I saw you,' shrugged Vaanes. 'It doesn't matter anyway. As soon as we get to the surface, myself and the others will leave you and your motley band.'