Descending into the stygian darkness of the mountainside, the rock passageway had eventually opened into a wide chamber where perhaps some underground earthquake had ripped an underground manufactory apart. Buckled, iron columns supported a bowing ceiling on vast, riveted girders, and beams of murky light speared down through shattered coolant towers that pierced the roof and illuminated the echoing space. Twisting bridges of knotted rope connected the forests of columns and a great pit had been dug or drilled in the centre of the manufactory floor where something unseen glittered and twisted in the dim light.

Piles of shattered machinery lay rusting in pools of moisture and groups of the Unfleshed, hundreds of them, gathered around them, their red bodies wet and glistening. These Unfleshed were the true monsters, so mutated and deformed as to be unable to hunt, or - in some cases - even move. Piles of altered flesh, twisted limbs without number and warped symbiotes of fused flesh that gibbered and howled in constant pain.

'So many of them…' said Uriel.

Further comment had been prevented as they were herded down into the depths of the manufactory and the Lord of the Unfleshed indicated that they should sit in the lee of a great pressing machine, with hammers the size of a battle tank.

'You. Not move.'

'Wait,' said Uriel. 'What do you want with us?'

'Tribe needs talk. Decide if you Unwanted like us or just meat. Probably we kill you all,' admitted the Lord of the Unfleshed. 'Good meat on your bones and fresh skin to wear.'

'Kill us?' snapped Vaanes. 'If you're just going to kill us, then why the hell did you bother to bring us here, you damn freak?'

'Weak of Tribe need meat,' rasped the monster, staring at Ellard with undisguised appetite. The sergeant had surprised them all by surviving the journey, though Uriel saw that he surely could not live much longer. Blood soaked the makeshift bandage of his tattered uniform jacket and his face was deathly pale. 'They cannot hunt, so we bring meat to them.'

'You had to ask,' growled Pasanius.

Vaanes shrugged and slumped to the ground with his back to the Ultramarines.

The Lord of the Unfleshed had then departed, making his way down to the floor of the manufactory to rejoin his tribe, leaving them in the company of a dozen gigantic monsters, each larger than a dreadnought and equipped with a fearsome array of gnashing fangs and long, dripping talons.

Since then, they had waited for hours in the stinking twilight as their captors - or brethren - debated whether to kill them or not. The creature Uriel had fought in the outflow pool was one of their guards, though it still appeared not to care about the weapon lodged in its flesh.

'Damn it, but I wish I knew what they were doing,' said Uriel, turning from the creatures that surrounded them.

'Do you?' said Pasanius. 'I'm not so sure.'

'We can't stay here. We have to get back to that fortress.'

'Back to the fortress?' laughed Ardaric Vaanes. 'Are you serious?'

'Deadly serious,' nodded Uriel. We have a death oath to fulfil, to destroy the daemonculaba or die in the attempt.'

'You'll die then,' promised Vaanes.

'Then we die,' said Uriel. 'Have you heard nothing I have said to you, Vaanes?'

'Don't you dare lecture me about honour and duty, Ventris,' warned Vaanes. 'I have seen enough of what your honour has to offer. Most of us are already dead, and for what?'

'No warrior ever died in vain who died for honour in the service of the Emperor.'

'Spare me your borrowed wisdom, Ventris,' sneered Vaanes. 'I have had my fill of it. If we survive this, there's no way I'm going anywhere near that fortress again. I am done with your heroics and will leave you to die.'

'Then I was wrong about you, Vaanes,' said Uriel. 'I thought you had honour left within you, but I see now that you do not.'

Vaanes ignored Uriel and stared sullenly at the lumpen, misshapen beasts that watched over them.

Uriel turned to Pasanius and said, 'Then we are on our own, my friend.'

'So it would seem,' agreed Pasanius, slowly, and Uriel could see that his friend was struggling to speak - burdened by the terrible weight of guilt.

An awkward silence fell between the two friends, neither knowing the right way to break it or how to begin to say what needed to be said.

'Why didn't you tell me?' said Uriel at last.

'How could I?' sobbed Pasanius. 'I was tainted. Touched by evil and corrupted!'

'How? When?' asked Uriel.

'On Pavonis, I think,' said Pasanius, the words, now undammed, pouring from him in a rush of confession. 'You remember that I hated the augmetic arm the moment the artificers of the Shonai cartel grafted it to me?'

'Aye,' nodded Uriel, remembering how Pasanius had complained that the arm could never be as good as one grown strong through a lifetime of war.

'I didn't know the half of it,' continued Pasanius. 'After a while I got used to it, even began to appreciate the strength in the arm, but it was when we fought the orks on the Death of Virtue that I first realised something was wrong.'

Uriel well remembered the desperate fighting to destroy the ork and tyranid infested space hulk that had drifted into the Tarsis Ultra system and heralded the great battle against a splinter fleet of bio-ships from Hive Fleet Leviathan.

'What happened?'

'We were fighting the orks, just before you killed their leader, you remember? One of the greenskins got behind me, nearly took my damn head off with his chainsaw.'

'Yes, you took the blow on your arm.'

'Aye, I did, and you saw the size of that blade. My arm should have been hacked in two, but it wasn't. It wasn't even scratched.'

'But that is impossible,' said Uriel.

'That's what I thought, but by the time we got away and were back at the Thunderhawk, it was as good as new, not a scratch on it.'

'I remember…' whispered Uriel, picturing Pasanius's arm reaching down to haul him to safety when their demolition charges had begun to tear the space hulk apart. 'It shone like silver.'

'I know,' agreed Pasanius, 'but it didn't register on me until we were back aboard the Vae Victus that my arm should have been pulverised. I thought maybe I'd imagined how hard I'd been hit, but now I know I didn't.'

'How is it possible? Do you think the adepts of Pavonis had access to some form of xeno tech?'

'No,' said Pasanius, shaking his head. 'The silver-skinned devils we fought beneath Pavonis, the servants of the Bringer of Darkness, they could do the same thing. No matter how hard you cut, stabbed or shot them, they could get back up again, their bodies putting themselves back together right before your eyes.'

'The necrontyr,' spat Uriel.

Pasanius nodded. 'Aye, necrontyr. I think maybe part of the Bringer of Darkness went into me when it cut off my arm, something corrupt that waited and then found a home in the metal of my new arm.'

'Why did you say nothing?' said Uriel. 'It was your duty to report such a thing.'

'I know,' said Pasanius, dejectedly. 'But I was ashamed. You know me, it's always been my way to deal with things myself. I've been that way since I was a boy on Calth.'

'I know, but you should still have reported it to Clausel. I will have to report it when we get back to Macragge.'

'You mean if we get back,' reminded Pasanius.

'No,' said Uriel, emphatically. 'When.'

Uriel turned as he heard footfalls approaching. Colonel Leonid, his face gaunt and worn stood behind him and said, 'Sergeant Ellard is dead.'

Uriel looked over to where the big man lay, and stood, placing his hand on Leonid's shoulder. 'I am sorry, my friend. He was a fine man and a good soldier.'

'He shouldn't have had to die like this, alone in the darkness.'