'You kill Iron Warriors well, both of you,' he said.

Uriel took the measure of this Space Marine before answering, seeing a confident, almost arrogant swagger to his posture.

'I am Uriel Ventris of the Ultramarines, and this is Pasanius Lysane. Who are you?'

The warrior sheathed the lightning claws on his gauntlets and reached up to release the vacuum seals on his gorget. He removed his helmet and took a lungful of the stale air of Medrengard before answering.

'My name is Ardaric Vaanes, formerly of the Raven Guard,' he said, running a hand over his scalp. Vaanes's hair was long and dark, bound in a tight scalp lock: his features angular and pale, with deep-set hooded eyes of violet. His cheeks were scarred and he bore a trio of round scars on his forehead above his left eye, where it looked as though long service studs had been removed.

'Formerly?' asked Uriel warily.

'Aye, formerly,' said Vaanes, stepping forward and offering his hand to Uriel.

Uriel eyed the proffered hand and said, 'You are renegade.'

Vaanes held his hand out for a second longer before accepting that Uriel was not going to take it and dropped it to his side. He nodded. 'Some call us that, yes.'

Pasanius stood next to Uriel and said, 'Others call you traitor.'

Vaanes's eyes narrowed. 'Perhaps they do, but only once.'

The three Space Marines stared at one another in silence for long seconds before Vaanes shrugged and walked past them towards the wrecked camp.

'Wait,' said Uriel, turning and following the renegade. 'I don't understand. How is it you come to be here?'

'That, Uriel Ventris, is a long story,' replied Vaanes, as they passed through the gate into the blazing camp. 'But we should destroy this place and be gone from here soon. The Unfleshed are close and the scent of death will draw them here quickly.'

'What about all these people?' asked Pasanius, sweeping his arm around to encompass the weeping prisoners outside the camp.

'What about them?'

'How are we going to get them out of here?'

'We're not,' said Vaanes.

'You're not?' snapped Uriel. 'Then why did you come to rescue them?'

'Rescue them?' said Vaanes, gesturing to his warriors, who began methodically working their way around the warehouse buildings and placing explosive charges. 'We didn't come to rescue them, we came to destroy this camp and that is all. These people are nothing to me.'

'How can you say that? Look at them!'

'If you want to rescue them, then good luck to you, Uriel Ventris. You will need it.'

'Damn you, Vaanes, have you no honour?'

'None to speak of, no,' snapped Vaanes. 'Look at them, these precious people you want to save. They are worthless. Most do not survive to reach the skinning chasm anyway and the ones that do soon wish they had not.'

'But you can't just abandon them,' pressed Uriel.

'I can and I will.'

'What is this camp anyway?' asked Pasanius. 'A prison? A death camp?'

Vaanes shook his head. 'No, nothing so mundane. It is much worse than that.'

'Then what?'

Vaanes grabbed the handles of the roller shutter door of the nearest warehouse and hauled it open, saying, 'Why don't you find out?'

Uriel shared a wary glance with Pasanius as Ardaric Vaanes gestured that they should enter the building. A powerful reek of human waste gusted from within, mixed with the stench of rotted flesh and the stink of desperation. Flickering lights sputtered within and a low sobbing drifted on the stinking air.

Uriel stepped into the brick building, his eyes quickly adjusting to the gloom within. Inside, the warehouse was revealed to be a mechanised factory facility, with iron girders running the length of the building fitted with dangling chains and heavy pulley mechanisms on greased runners. Mesh cages on raised platforms ran along the left-hand side of the building, a mass of pale flesh filling each one, with gurgling pipes and tubes drooping from bulging feed sacks suspended from the roof.

A trough that reeked of human faeces ran beneath the cages, clogged and buzzing with waste-eating insects. Uriel covered his mouth and nose, even his prodigious metabolism struggling to protect him from the awful stench. He walked forwards, his boots ringing on the grilled floor as he approached the first cage.

Inside was a naked man, though to call him such was surely to stretch the term. His form was immense, bloated and flabby, and his skin had the colour and texture of bile, with a horrid, clammy gleam to it. Rusted clamps held his jaw open while ribbed tubing pulsed with a grotesque peristaltic motion as nutrients and foodstuffs laced with growth hormones were pumped into him as another tube carried away his waste. Coloured wires and augmetic plugs pierced the flesh of his sagging chest, no doubt artificially regulating his heart and preventing the cardiac arrest that his vast bulk should have long ago brought on.

His limbs were thick, doughy lumps of grey flesh, held immobile by tight snares of wire, his features lost in the flabby immensity of his skull, his eyes telling of a mind that had long since taken refuge in madness. Uriel felt an immense sadness and horror at the man's plight - what manner of monster could do this to a human being?

He moved on to the next cage, finding a similar sight within, this time a naked woman, her body also bloated and obscene, her belly scarred and ravaged by what looked like repeated and unnecessary surgery. Unlike the occupant of the previous cage, her eyes had a vestige of sanity and they spoke eloquently to Uriel of her torment.

He turned away, appalled at such hideousness, seeing that there were hundreds of such cages within this darkened hell. Repulsed beyond words, yet drawn to explore further, he crossed the chamber to see what lay on the other side of the building. More cages occupied the right-hand side of the building, but these were narrower, occupied by splayed individuals who looked like the poor wretches Uriel had once seen on a hive world that had been cut off from the agri world it had relied upon for foodstuffs. Starving men and women were hung from iron hooks, wired to machines that kept them in a hellish limbo between life and death as their body fat was forcibly sucked from them by hissing pumps and industrial irrigation equipment.

Their skin hung loose on their bodies and drooped from their emaciated frames in purulent sheets. Uriel now knew the fate of those in the cages behind him. Fattened up artificially so the skin might stretch to obscene proportions, then ultra-rapidly divested of their bulk that they might be skinned to provide swathes of fresh skin.

But why? Why would anyone go to such lengths to harvest such vast quantities of human skin? The answer eluded Uriel and he felt an all-consuming pity well up within him at the plight of these prisoners.

'You see?' said Ardaric Vaanes, standing behind him. 'There is nothing you can do for them. Freeing these… things is pointless and their death will be a blessed release.'

'Sweet Emperor,' whispered Uriel. 'What purpose does this cruelty serve?'

Vaanes shrugged. 'I do not know, nor do I care. The Iron Warriors have built dozens of these camps in the mountains over the last few months. They are of importance to the Iron Warriors, so I destroy them. The "why" of it is irrelevant.'

'Are all the buildings like this one?' asked Pasanius, his face lined with sorrow.

'They are,' confirmed Vaanes. 'We have already destroyed two such camps, and they were all like this. We must destroy it now, for if we do not, the Unfleshed will come and there will be a feasting and a slaughter the likes of which you cannot imagine.'

'I do not understand,' said Uriel. 'The Unfleshed? What are they?'

'Beasts from your worst nightmares,' said Vaanes. 'They are the by-blows of the Iron Warriors, abortions given life who escaped the vivisectoria of the Savage Morticians to roam the mountains. They are many and we are few. Now, come, it is time we were gone.'