‘No,’ Alberich said. He smiled at her, abruptly calm. ‘No, it isn’t funny. I’ll take that book. You will give it to me.’

‘Or you’ll cut your hostage’s throat?’ Irene said. She was still shaken from the sudden flux. Everything about it had been wrong. The Fae were bad enough, but this softening of reality had been much worse. She’d been ready to face death, even, but that – no.

‘Be reasonable,’ Alberich said. ‘I’ll need a new skin soon. Another Librarian’s skin would suit me quite well. So would Vale’s position in society. Don’t give me any excuses, Ray. Don’t give me any more reasons to slit this man’s throat and then rip your skin off. Be very polite, be very helpful, and listen to what I’m about to tell you.’

Irene simply jerked her head in a nod. She was afraid of touching off that anger again, afraid for Vale’s sake – and, more honestly, terrified for herself.

‘Where was I?’ For a moment he reminded her of Dominic Aubrey, making her wonder how much of that charade had been imitation and how much had been genuine Alberich, filtered through a dead man’s skin. She’d liked Aubrey. ‘Ah yes. Motivations. Tell me, Ray, what is the purpose of the Library?’

‘To preserve,’ Irene said automatically.

Alberich nodded as though he’d expected that answer. ‘Now tell me – tell me honestly and sincerely – that you’ve never thought about using the knowledge you’ve helped preserve. To change the worlds around you for the better. Or do you think that they’re already perfect?’ His voice dripped sarcasm.

Irene felt as if she was having to run through a minefield blindfolded, with no idea what the correct answers were. ‘Of course I’ve thought about it. But you know that they don’t send us – ’ For a moment she wished she hadn’t used the word us. It brought them onto the same level. – ‘out on missions unless they’re certain that they can trust us.’

‘And you accept that so readily?’

‘It’s the price I chose to pay to get what I wanted.’ She’d never wanted anything else.

‘Don’t think I make this sort of offer to just any Librarian,’ Alberich went on. ‘You’ve shown a degree of intelligence which has impressed me. Not all Librarians know when and how to break the rules.’

‘Excuse me a moment,’ Vale said politely, while Irene wondered if Alberich gave the normally I wouldn’t spare your life, but you’re special spiel to every Librarian he met. ‘Might I ask what happened to the original Miss Mooney?’

‘Who?’ Alberich said blankly.

‘The woman whose body you are occupying.’ Vale’s tone dripped with cold disdain. ‘Jennifer Mooney, one of the more influential figures in the Iron Brotherhood. I recollect the face from one of Singh’s photographs. I wish I had remembered it earlier.’

‘Oh.’ Alberich smiled. ‘Ah, Ms Mooney – I had to take her identity in quite a hurry, in order to use the Brotherhood as a diversion.’

Irene could have kicked herself. Of course. The alligator attack on the Embassy, to distract Silver. She clearly remembered him dashing off to protect ‘a book’. And Alberich had been right on the scene afterwards, leading to their almost-drowning. Then there was the assault on the Natural History Museum – all of it made sense now. That was what he’d meant earlier when he’d said that he had taken control of the Brotherhood. She saw Vale’s face twitch in mortified humiliation. He must be having the same chain of thought, and blaming himself for not deducing it earlier.

‘And they have the most baroque ideas about false names and false identities. You’d think that a pro-technology group would be more efficient about record-keeping, wouldn’t you? Now if only you’d said “Damocles”, I’d have known precisely whom you meant.’

He didn’t even know her name. For some reason, that utterly chilled Irene through and through. And Alberich must have seen it in her face, for he went on, ‘And now, Mr Vale, no more words; your vocal cords are locked shut.’

Irene saw the sudden flare of panic in Vale’s eyes and saw his mouth move, but he made no sound.

I don’t think he copes well with being helpless.

Anger fought with the fear that held her still too, its heat against the cold. And I don’t think I cope well, either.

‘Let us assume that you have three options, Ray,’ Alberich said, dropping back to his conversational tone. ‘The first is that you agree to help me. Give me the book, swear your loyalty by certain oaths which I shall dictate to you, and join me. The Library was never meant to be just a storehouse for books and a school for the obsessive. It could change worlds. It could unite alternate worlds. It has potential, you have potential, and that potential is being wasted. I would swear my protection to you, just as you would swear your loyalty to me, and you would be safe. You could learn to use Fae powers, just as I have done. Perhaps in time you would challenge me, but together we would do terrible and wonderful things. You know that some key books can change the worlds to which they are linked. Help me, and we will change them for the better. You’ll have the power to make things better. If you refuse that power, then that’s a choice in itself, isn’t it?’

All the worlds for her own. Of course she wasn’t going to take the bargain. Of course she could never be his minion and slave. But the thought of the pure irresponsibility of doing precisely as she wanted, with the power to do it . . .