‘Very well. Your associate Bradamant arrived here before you did, and created an identity as the thief Belphegor. An intelligent piece of work. She must have planned to conceal her theft of this specific book among the thefts of other books. A needle in a haystack, as the saying goes. Do you suppose she would be prepared to return the other ones?’

Irene thought about it. Vale’s theory made a great deal of sense, and was a step ahead of where she’d managed to get to. (She’d always wondered, or even daydreamed, what it was like to actually work with great detectives, rather than just read about them. It was more annoying than she’d expected.) The odds were that Bradamant had kept the books – after all, if her private mission had been successful, then she could have donated them to the Library as well. ‘I can ask her,’ she offered. ‘The current mission is definitely more important than these other books.’

‘But it’s our mission!’ Kai put in.

Irene sighed. It was well past midnight. It had been a very full day. She was tired to the bone. ‘Look, Kai. At the moment, the most important thing is keeping that book out of Alberich’s hands. If he wants it, then it’s paramount that he doesn’t get it. And the second most important thing is getting it to the Library. I admit it’s not going to look good on my record if I fail. But when it comes down to it, I don’t care if I bring it in, or you bring it in, or if Bradamant brings it in and takes the credit and ends up spending the next ten years rubbing my nose in it. And if that means promising her the book in exchange for handing back the other books to Vale, then I will do it.’

‘That’s very noble,’ Kai said dubiously, ‘but it doesn’t solve our original problem. Where is the book?’

‘I believe that is something we can discover when Madame Bradamant is here to be questioned,’ Vale said briskly. ‘She agreed to come and see you tomorrow, I think? And if Singh does not release her, then we can go and question her in prison.’

Irene nodded. She was about to continue, when Vale held up his hand. ‘One thing more. When you made that reference to “significant connections” and “books specific to an alternate” – would you mind expanding on that?’

Damn him. Irene had been hoping to skate past that without going into further detail. Belatedly, she decided that she should never have mentioned that bit in the first place. Stupid of her. ‘Some books have a significant connection to the alternate that they come from,’ she said reluctantly. ‘They help anchor the Library to that alternate. It’s not a bad thing in itself. The Library’s a stabilizing force, so it even helps ward off chaos influences like Fae.’

That was half of it. The other half of it – the possibility that books with a significant connection to the alternate world could affect that world itself, could somehow even change it – was only a theory at her level in the Library. It was a theory that she was increasingly wanting to research in more detail, but there wasn’t time for that at the moment. It was also something that she definitely wasn’t going to tell Vale. Call her a cynic, but Irene suspected that if she were to tell him that, then there would be no way in hell that he’d cooperate in getting the book for her. He’d be far too concerned at what it might mean for his own world. After all, he’d made it clear that he didn’t necessarily trust the Library’s intentions.

‘And my world?’ Vale pounced on her words. ‘Which books are “significant” here?’

‘I don’t know, sir.’ She saw Vale was about to object, and she shook her head. ‘No, please. Believe me, Mr Vale. We don’t get told. They don’t tell us. It’s dangerous knowledge.’

He leaned back in his chair, his expression hungry and unsatisfied. ‘And aren’t you ever curious, Miss Winters? Don’t you want to know?’

‘You’re suggesting that I have some sort of academic curiosity about the fact,’ Irene said curtly. Out of the corner of her eye she could see Kai leaning forward. ‘I’ve already told you that our interest is in books. Not . . .’ She looked for words that would convey her meaning with sufficient strength. ‘Not in overarching world-changing forces.’

‘Yes, Miss Winters,’ Vale said drily. ‘That is indeed what you have told me.’

The unspoken accusation of lying, or at the very least prevarication, hit her like a slap across the face. It didn’t help matters that it was in some respects true. She lowered her eyes and couldn’t answer him. Worst of all, for the first time in years, we’re just doing this to save the books sounded petty, and choosing not to know more seemed childish.

‘And yet there might be good reasons for not knowing,’ Vale went on, talking over her bowed head. ‘Perhaps for fear this Alberich fellow might find out. Perhaps simply the senior members of this library would refuse to tell you, if they knew themselves. And perhaps you would simply refuse to tell me, for your own safety, or for mine.’ His voice was dispassionately kind. She didn’t deserve it. ‘It must be very frustrating, Miss Winters. Wondering.’

She still couldn’t bring herself to look up. ‘If it was important,’ she said, ‘then they’d tell me.’

‘Or possibly it is too important to tell you,’ Vale answered. ‘Just as with the suggestion that the book contains classified information, which we discussed earlier. We lack sufficient information to know for certain which is true. But one thing is sure. We cannot allow this book to fall into Alberich’s hands.’