'The forces of the Dark Powers make war upon one another for their own amusement. It doesn't necessarily mean anything.'

'True, but all I have learned of the Iron Warriors from Librarian Tigurius leads me to believe that they are consumed by bitterness and malice, not given to capricious whims. Whoever is attacking this fortress is doing so for more than their amusement.'

'You could be right,' agreed Uriel. 'Come on, there is only one way to find out. The summit is near.'

Once again they set off, and after what could have been no more than another hour's climb through drifting banks of stinking steam and yet more piles of bones, they crested the summit before them. Uriel had expected the ground to drop away from them, descending to the plains below, but instead the ground flattened into a rubble-strewn plateau of jagged spikes of rock and snaking cracks that drooled a yellowish fog. One of the bloated balloons was almost directly overhead and Uriel now saw that the cables dangling from it were barbed and as thick as a man's thigh, scraping great furrows in the grey powder of the ground as it drifted.

'Listen,' said Uriel, dropping to one knee.

Pasanius was silent, cocking his head and listening for what Uriel had heard.

Amid the bass rumble of artillery fire and the hammering of distant forges, there was a pulsing, mechanical sound, such as might be made by a host of generators. Though it was hard to pick out any one sound from the omnipresent background noise of Medrengard, Uriel was certain it was coming from up ahead and was near.

'What do you think it is?' he asked.

'Engines perhaps?' suggested Pasanius.

'Maybe,' nodded Uriel.

'Maybe something we can steal.'

'My thoughts exactly,' grinned Uriel, pushing himself to his feet and moving cautiously through the rolling banks of stinking fog while hugging the tall pillars of rock. The noises grew louder as they approached, and as the clouds of smog parted, Uriel saw their source.

A sprawling complex of corrugated metal buildings, each the size of a large warehouse, squatted atop the plateau, surrounded by a high fence of razorwire topped with forests of iron spikes. Bodies hung draped from thick lengths of timber along the fence, their flesh desiccated and their limbs twisted at unnatural angles around the spars. Pillars of ashen smoke curled from a building of black brick near the centre of the camp and a low moaning permeated the air. A greasy, fatty residue coated the rocks and Uriel smelled a loathsome stench that reminded him of spoiled meat.

'This place reeks of death,' he whispered.

In the centre of the camp, a tall, armoured tower reared into the sky, thick iron girders and cable stays supporting a monstrous assembly that resembled the head of some gargantuan daemonic creature. Flames spouted from its eyes and nostrils, and its gaping mouth was filled with long gun barrels. Two bunkers guarded the entrance to the camp, their roofs sloped and festooned with spikes. Uriel could see the glint of heavy guns through the firing slits and knew that to approach this death camp, they would need to cross the interlocking fields of fire of both bunkers.

Beyond the razorwire barrier, Uriel could see warriors in iron grey armour patrolling the interior of the camp, and felt his instinctual hatred rise to the surface.

'Iron Warriors!' hissed Pasanius.

'Iron Warriors,' repeated Uriel, gripping the hilt of his sword tightly.

Traitors. Abominations. Chaos Space Marines… was there any other foe so vile?

These warriors sought the ruination of everything Uriel believed in and the destruction of the Emperor's realm. Every aspect of his soul cried out for vengeance.

'What is this place?' asked Pasanius as the shutter doors of one of the warehouse buildings screeched open and a host of the shambling mutant things they had killed earlier emerged. Behind them came a pathetic, shuffling mass of humanity, their heads cast down and their bodies swathed in baggy, flesh-coloured robes.

'Some kind of prison?' ventured Uriel, as the mutants herded the prisoners towards the gates of the camp. Were all these buildings filled with prisoners? The great daemonic head on the tower turned on grinding cogs to face the hundreds-strong column, huge streams of flame belching from its eyes. A booming voice roared from its mouth, speaking a language Uriel did not understand, but which sent aching spasms through his joints and muscles, as though the sound resonated within the darkest recesses of his brain.

The prisoners marched through the camp, the mutants stabbing at them with crackling prods and beating them with iron-tipped cudgels. The Iron Warriors marched ahead of the column, hideously perverted bolters carried across their breastplates. As they approached, the gate squealed open, the corpses hanging from it jittering in a grotesque imitation of life.

'Where are they taking them?' wondered Uriel.

'Oh, Emperor, no,' whispered Pasanius. 'They're taking them—'

'To be skinned alive…' finished Uriel as he saw that the prisoners were not swathed in baggy robes at all, but were all completely naked to the elements. Their flesh hung in huge flaps from their bodies, stretched beyond all normal proportions by some unknown means. Encrusted dewlaps drooped from emaciated arms, chests, legs and buttocks. Men and women clutched fold upon fold of stretched skin to their bodies for fear it would trip them, sagging bellies and drained teats hanging like empty sacks of dried leather from their wasted frames.

'They're taking them to the skinning platform. No, no…' said Uriel. 'But why?'

'Does it matter?' snarled Pasanius, gripping his flamer tightly his silver finger hovering over the ignition key. 'We can't let this horror go unpunished!'

Uriel nodded, feeling his hatred for the Iron Warriors reach new heights, but he forced himself to try and remain calm. To attack this column was suicide, they were directly in front of the bunkers and the gun tower, not to mention three Iron Warriors.

But to let such an affront against humanity go unmolested? To allow these traitors to butcher these people as though they were no more than animals?

Pasanius was right, such evil would not stand.

He could see righteous anger in Pasanius's eyes, but also something else, something darker. Uriel saw the light of a zealot in his battle-brother's eyes, the light of one who goes to battle with a death wish, where survival is irrelevant.

Was there more to Pasanius's desire to fight than the obvious reasons of humanity?

It seemed to Uriel that there was, but such were questions for when, or if, they lived through the next few minutes.

Uriel drew his sword, his thumb hovering over the activation rune.

He gripped Pasanius's shoulder guard and said, 'If we do not survive, then it has been an honour to call you my friend.'

Pasanius nodded, but did not reply, his gaze never wavering from the approaching column of slaves, mutants and Iron Warriors.

His eyes suddenly narrowed and he nodded at something over Uriel's shoulder. 'What in the name of the Emperor?'

Uriel turned and saw a number of figures moving stealthily through the high crags that surrounded the camp.

'Are these the things that have been tracking us through the mountains?'

'No,' said Pasanius. 'I don't think so. They look like…'

'Space Marines!' breathed Uriel as he saw two figures in green power armour rise from behind a cluster of boulders and aim missile launchers towards the camp. The Iron Warriors below had not noticed the figures moving above them and Uriel realised with wild enthusiasm that this must surely be an ambush!

A pair of missiles shot from the Space Marines' weapons and slashed towards the leftmost bunker, slamming into the rockcrete and obscuring it in a bright explosion of fire and smoke. Another flashing pair of contrails hammered into the opposite bunker from somewhere high above Uriel and Pasanius and the second bunker vanished in a fiery explosion.