‘Through here,’ Vale said, pointing at a door in one of the smaller battlements circling the landing area. Beyond that bulged the wide glass curved roof of what must be the Reading Room. Irene hadn’t had time to admire it in this alternate, but she’d seen versions of it in other Londons, and she shuddered to think how close they came to landing on it. Though surely in a world of airships and personal helicopters, the curators must have taken some sort of precautions against things or people crashing through it from above?

She really hoped so. She’d seen too many glass pyramids and domed roofs and huge chandeliers that were just accidents waiting to happen.

Vale had a few quick words with the guard, who flung the door open and practically saluted them through. And then they were inside, and out of the wind, and surrounded by comforting walls and walls of books. The rich, delightful smell of old paper, leather and ink permeated the place, washing away the pettier odours of blood and oil and smog.

Irene felt a desperate surge of nostalgia for her Library. Her life was more than just airship chases, cyborg alligator attacks, and hanging out with this alternate universe’s nearest analogue to Sherlock Holmes. She was a Librarian, and the deepest, most fundamental part of her life involved a love of books. Right now, she wanted nothing more than to shut the rest of the world out, and have nothing to worry about, except the next page of whatever she was reading.

‘Which way is Aubrey’s office?’ Vale demanded.

Irene frowned, trying to remember the route. ‘Third floor,’ she said, ‘along from the south stairs, two rooms east, then one south, then east again, I think that most of the stuff along there was European history.’

‘This way,’ Vale said, leading the way down a gallery of drawings and prints. ‘Do you have a strategy?’

A couple of men looked up disapprovingly from their sketchbooks at the noise. Their faces were full of we are far too polite to say so, but really you shouldn’t be making any noise at all.

Irene ignored them. ‘Get the book,’ she said to Vale. ‘Secure this building against Alberich. My invoking the Library won’t keep Bradamant out, so she’ll be safe once she gets here. I’ll contact my central authority for direct assistance.’

Vale raised an eyebrow. ‘Aren’t you going to tackle the fellow directly?’

Irene couldn’t meet his gaze. ‘I’d lose,’ she said.

‘This language of yours—’ Vale started.

‘I’d find it very hard to believe that other Librarians haven’t tried that against him already,’ Irene snapped before she could help herself. ‘And confrontations with Alberich generally end with him sending parts of their internal organs back to the Library. In neatly wrapped parcels. Someone said that they can tell it’s a parcel from Alberich because he always folds the paper in the same way.’

‘Miss Winters, just because this fellow has reached the status of an urban legend . . .’

‘He’s more than that,’ Kai said urgently. Their footsteps were loud in the stairwell. ‘You were there last night, Vale. He sealed us in the carriage and put a block on it which even I couldn’t undo.’ There was an unconscious arrogance to his voice. ‘And Aubrey, the Librarian stationed here previously. He would have been more experienced than Irene – no insult, Irene, but—’

‘Oh, don’t worry,’ Irene said with a shrug, surreptitiously flexing her hands and trying to decide how fully recovered she was. For the moment she was functional, if damaged. ‘You’re quite right. He wouldn’t have been stationed in an alternate like this unless he was competent, and he was older and more experienced than I am.’

‘It’s this floor,’ Vale said. They came out of the stairwell into a room blazingly full of painted hieroglyphics, icons and crosses with pointy end bits – Coptic, Irene decided. The light was artificial, presumably to spare the papyri from natural sunlight, but the colours leapt at them in a riot of gold, red and turquoise. ‘Straight ahead, then left. And may I suggest that Mr Aubrey had no warning that Alberich was coming. Presumably if he had done, then he could have secured himself and called for help from the Library, just as you intend to do?’

She didn’t want to hear this.

Casual strollers saw them coming and stepped out of the way. A couple of elderly ladies muttered something condemnatory about young people these days, as Irene strained to listen.

Irene knew that this was displacement behaviour, as the last thing she wanted to do was listen to Vale talking about tackling Alberich. Playing chess matches against masters who were certain to defeat you was one thing: you learnt about chess, and you didn’t die in the process. Getting into a fight with someone who would kill you (messily) failed to teach you anything useful, unless reincarnation was genuine, and you did die in the process. It was hard enough to have to consider how important the book might be to this world. She could only think in small steps. If Alberich wanted the book, that meant it was important, possibly even vital, to this world, and he mustn’t have it . . .

She was also trying to ignore Kai’s sympathetic glances from behind Vale’s back. Maybe there was a whole genre of literature written by dragons for dragons about how they sensibly stayed out of fights that they couldn’t hope to win, and flew away to do something very important somewhere else. Or maybe it was a bad idea to be distracting herself quite so thoroughly when they were almost at Aubrey’s office.