'So that's it, eh? Just shut up and trust you? Like we trusted Luther, and Jonson, and all those vultures from the Administratum?' Thuriel shouted back. His right hand fell to the pistol holstered at his hip. 'Never again, Daviel! You hear me? Never again!'

The nobleman glared at Daviel for a long moment. The knight regarded Thuriel coldly, pointedly folding his arms in the face of the other man's threat. The rebel gunmen at the back of the room fingered their weapons nervously. Before the situation could escalate further, however, Lord Malchial leapt from his chair and gripped Thuriel's left arm.

'Leave it, cousin,' Malchial hissed fearfully. 'Nothing good can come of this.'

Thuriel gritted his teeth in consternation, weighing his options. Finally, he drew his hand away from his weapon.

'For once, Malchial, you may be right,' the nobleman said. Thuriel swept a haughty gaze over the knights, Lady Alera and Zahariel. 'We're finished, do you hear? You'll not get another coin from me to finance your little games of deception. I'll find another way to set our people free from the likes of Jonson and his ilk. See if I won't.' He turned and stormed from the room, with a nervous Malchial close behind.

'Damn that Malchial,' Sar Daviel said as the door slammed shut behind them. 'Another moment more and Thuriel would have done something foolish. Then we could have been rid of the both of them.'

Zahariel frowned. 'Was it wise to let them go?' he asked.

'You'd rather he were here, using up good air?' Alera said disgustedly. She waved her hand in dismissal. 'Thuriel provides us with money and outrage, and not much else. He doesn't have any real support inside the movement. Let him go. We've got much more important things to worry about.'

Sar Daviel looked to Remiel. 'Things are far worse than we feared,' he said gravely.

Remiel nodded, but he continued to stare searchingly at Zahariel. 'Why have you told us this?' he asked his old pupil.

'Because we're running out of time,' Zahariel replied. 'We've got to stop the Terrans before they unleash their master ritual, but if we send in a major force of Astartes to search for them we risk drawing the attention of the Administratum.'

'Who wouldn't hesitate to condemn the planet - and its people - if they learned the truth,' Remiel concluded.

'Condemn?' Alera said. 'What does that mean?'

'The Imperium views warp taint as… a cancer, if you will. A tumour on the human soul,' Remiel said. 'Not without reason, of course. No sane person wants to see a return of Old Night. But the problem here is that Caliban's taint runs deeper than just a handful of debased individuals; it permeates the very bedrock of the world.'

'Then how does one go about curing it?' she said, her voice rising with exasperation.

The old master sighed. 'With fire. What else?' He eyed Zahariel coldly. 'The Imperium would relocate the Legion and as many of its loyal servants as it could. Perhaps a few hundred thousand could be saved. The rest…'

'That's why this must be kept secret,' Zahariel said calmly. His eyes never left Remiel's.

The old master's eyebrows rose. 'That sounds like something very close to rebellion, young Zahariel.'

The Librarian shook his head. 'Luther and I swore an oath to protect the people of Caliban, long before the coming of the Emperor,' he replied. 'As did you.'

Sar Daviel nodded slowly. 'All right,' he said. 'What do you want from us?'

'A truce,' Zahariel said simply. 'Help us find the Terrans quickly and quietly, and we'll send in a kill-team to eliminate them.'

Alera shook her head. 'I don't think so,' she said. 'Leave these sorcerers to us. We can take care of them.'

'Would that were so, Lady Alera,' Remiel said heavily. 'But Zahariel is right. Our people are no match for these creatures. This is a task for the Astartes.'

'But we don't even know for certain that these sorcerers are here,' Alera protested. 'A truce at this point benefits the Imperials, not us! Their control of the arcology is balanced on a knife edge; if we give them time to catch their breath, bring in more reinforcements…' the noblewoman's voice trailed away as she watched a wordless exchange pass between Remiel and Sar Daviel.

'There's something else, isn't there?' she asked.

Daviel nodded. 'We didn't tell you before for reasons of security,' he said gravely. 'But we've lost contact with a number of our sub-level cells over the last two weeks.'

'How many cells?' Alera demanded.

'Fourteen,' Remiel answered. 'Possibly as many as sixteen. Two others missed their last scheduled report this morning, but that could be the result of equipment failure.'

The news sent a jolt down Zahariel's spine. 'How many cells do you have in the sub-levels?'

Daviel shifted uncomfortably. 'A significant number,' he said. 'The Jaegers don't have the manpower to penetrate much beyond sub-level two, so we keep our combat teams on the lowest sub-levels between raids.'

'How many men have you lost so far?' Zahariel pressed. 'Tell me!'

'One hundred and thirty-two,' the maimed knight answered. 'All of them well-trained and well-equipped, and all of them lost without so much as a single vox transmission. Frankly, we were starting to suspect that you'd sent Astartes teams into the sub-levels to root us out.'

Zahariel shook his head. 'It's begun,' he said. 'They're gathering bodies, just like they did at Sigma Five-One-Seven.'

Alera's face twisted in a bitter grimace. 'As though the Terrans would have a hard time finding corpses in that charnel house.'

'Charnel house?' Zahariel echoed. 'What do you mean?'

Lady Alera stared open-mouthed at the Astartes. 'Don't pretend you don't know,' she said, her eyes blazing angrily.

Zahariel held up a hand. 'On my honour, lady, I have no idea what you're talking about.'

'Then who is responsible for the atrocities committed in your name?' she said coldly. 'Five million people, crammed into three levels built to hold a quarter of that number. No power, intermittent supplies of food and water, no functioning sanitation… What did you think was going to happen? People are dying by the hundreds every day. The bodies are tossed down maintenance shafts or piled in lifts and sent to the lower levels, so the survivors don't have to live among the corpses.'

The news stunned Zahariel. 'This wasn't reported back to us at Aldurukh,' he said, his voice choked with outrage. 'Is there any way to know how many have died?'

Remiel shook his head. 'Tens of thousands, son. Perhaps more.'

Zahariel nodded thoughtfully. 'The Terrans knew. That's why they returned to the arcology.' He looked to Remiel. 'The incident at Sigma Five-One-Seven was a field test,' he said, like a pupil solving a problem for his tutor. 'They needed to refine the ritual, test its effects on a smaller scale before unleashing it here.' An image came to him, of an army of animated bodies shambling and crawling up out of the depths to slaughter the millions penned like sheep in the sub-levels above.

'There's no time to waste,' he said. 'If there's another outbreak of violence here, the Terrans will have all the psychic energy they need to begin a large-scale ritual. We've got to find them before it's too late.' Zahariel stepped forward, holding out his empty hand to the rebels. 'Will you agree to the truce?'

Alera and Sar Daviel looked to Remiel. The old master stared at Zahariel's open hand for a long moment, a tormented look on his face. Finally, he straightened and looked his former student in the eye.

'For the pact to be binding, it must be sworn by both leaders,' he said sternly. 'If Luther gives me his hand, then I shall take it. Until then, we can have no truce between us.'

'Then come back with me to Aldurukh,' Zahariel said, his voice taut. 'We can be back at the fortress in two hours.'