‘Your face is an open book, Magos Drusher,’ she said. ‘Micro-spasms in your platysma, zygomaticus and levator labii superioris. Involuntary dilation of the pupils. You are terrified. Your composure is a front. Bravado.’

‘My levator labii superioris is doing just fine,’ replied Drusher. ‘Of course I’m terrified. You just killed a man, and you’re aiming a gun at me. You realise your fate will be appalling. I don’t know what it will be precisely, but I doubt the Inquisition treats heretics with much mercy.’

‘It does not,’ she agreed. ‘But then, you’re not with the Inquisition. The Rot-God-King’s Holy Ordos have no inkling of this affair. Eisenhorn is a rogue, magos. He is extreme and dangerous, even by their standards. They declared him hereticus many years ago, and they hunt him as keenly as they hunt the Cognitae. There – the platysma again. You didn’t know that.’

‘I guessed,’ said Drusher. ‘This whole operation lacked legitimacy. I don’t know him well, but I believe he is determined–’

‘Oh, Eisenhorn believes his cause is just. In his arrogance.’

‘And he hunts for you?’

‘Bringing down the Cognitae is his life’s work,’ she said. ‘The ruthless zeal with which he pursues us is the main reason he was disowned by his ordo masters. Be clear, Magos Drusher. No one is waiting to hear from him. No one is coming to save you. No one knows you’re here. He’s done. You’re all done.’

‘You say that confidently, Mamzel Jaff, but you’re not certain, are you? A twitch of the masseter, a little tremble of the corrugator supercilii. Doubt, plain as day.’

Jaff frowned and shot her free hand to her face, involuntarily.

‘You’re a little shit,’ she said, glaring at him.

Drusher smiled back. He was no reader of micro-expressions. He’d made it up just to rattle her.

He heard footsteps. A man was coming up the metal steps onto the gantry. He was tall and heavyset, with piercing violet eyes that contrasted strangely with his olive skin, jet-black hair and full beard. He wore a leather-jack suit with a mesh-armour jacket. A large autorifle hung across his shoulder. Three people followed him: a hard-faced woman with cropped red hair, a tall, heavily tattooed man and an overweight man with hooded eyes.

‘Why is he alive, Jaff?’ the bearded man asked. His voice was extraordinarily deep.

‘A useable subject, Gobleka,’ she replied. ‘High intelligence quotient.’

The man looked at Drusher as if he were an annoying stain on good carpet. Gobleka. Drusher recognised the name. The heretic Eisenhorn’s interrogator had been hunting on Gershom.

‘Have you questioned him?’ Gobleka asked Jaff.

‘He knows nothing.’

‘Establish that as a fact,’ hissed Gobleka. ‘Thanks to your poor work, the agents of the damn ordos are inside the hall. I want them all found and extinguished, so we’d better know everything they know.’