Kai drifted downwards: as before, the velocity and wind didn’t reach Irene or do more than ruffle her hair, and she could enjoy the view of oncoming clouds and smog. Typical weather for this world, or at least for this London. ‘Can you go to any world?’ she asked, curious.

‘To any world I know, or to any person I know.’ Kai sounded smug again, which wasn’t surprising: Irene’s travel through the Library was rather more specific and limited. ‘I could find you wherever you were.’

‘Even in the Library?’

There was a pause. ‘Well, no. I can’t reach the Library. None of my kindred can. It’s barred to us by our usual way of travel. The only way I can get to it is by being taken there by a Librarian. Like you.’

Well, that explains why the dragons haven’t taken us over for our own good. Irene made some soothing noises of agreement, and wondered exactly why dragons couldn’t reach the Library, and if she had a hope in hell of finding out while acting as mentor to a dragon apprentice. Her superiors could be very paranoid, and it might earn her some much-needed favour.

Kai snaked through the air. ‘Ready to go down?’ he said.

It would have been nice to sit up here above the clouds for a while longer, discussing metaphysics and dragons and other interesting topics, but there was simply too much on her schedule. ‘Let’s do it,’ Irene said.

They came down with a rush, slicing through the clouds and leaving streamers of mist behind them, with a speed that would have left Irene prostrate if it had been natural flight – well, as far as any flight on the back of a giant supernatural pseudo-reptile could be termed natural. She realized, with the technical part of her mind that wasn’t occupied with Oh my god please slow down, that Kai must be going as fast as possible to make it less likely that people would see him. Even in London, a dragon might attract attention and would be hard to mistake for an airship.

She could see the British Library below, and the glass pyramid on top of it. There was a small zeppelin tethered to the roof, floating there ready for action, and Kai had to adjust his flight path to avoid it. Two guards had seen him incoming and came running to intercept him, hands on truncheons.

Plus several points for duty, minus a lot more points for intelligence, for running towards an approaching dragon rather than running away from an approaching dragon. Irene waited till Kai had settled to the ground, then slid off his back. Ideally she would have walked towards the guards, but for some reason her legs didn’t want to work, and she leaned against Kai instead. ‘Good afternoon,’ she said, trying to sound charming.

The guards looked her up and down. Admittedly her National Guard costume, her harshly braided hair and the fact that she’d been gently smoked (or lightly kippered) didn’t make her look like the most trustworthy person. Time for the other option.

She pushed away from Kai, standing upright, and took a deep breath. Light flared behind her. That must be Kai turning back into a human. Good, it’d make the phrasing easier. ‘You perceive that I and the person behind me are normal but unimportant people, who have a right to be here on the roof, but are not worth your time and interest.’

The use of the Language to affect someone’s perceptions always took energy. She swayed as she felt the drain on her reserves. But it worked. The guards developed the vaguely puzzled look of men trying to remember exactly what had been so important. One of them waved her and Kai towards the door into the main building, with a mumbled, ‘Please enjoy your visit to the British Library.’

Of course the problem with using the Language that way was that it might wear off at any moment. It was only useful up to a point. Kai knew that just as well as Irene, so the moment they were inside the building, he led the way in a rapid trot down the book-lined storage corridor, and they didn’t stop till they were a few turnings away.

‘Are you going to open a direct portal to the Library from one of these rooms, or do you want to go down to the fixed entrance?’ he asked.

Irene ran her hands over her hair and grimaced at the amount of ash that came away. ‘I think we’ll use the fixed entrance,’ she said. ‘I know we’ll probably run into people on the way down there, but at least we know where we’ll come out in the Library, that way. Besides, after last time I stashed a couple of overcoats in the room next to it. It’ll do to cover up these outfits till we can get back to our lodgings.’

‘We could just change clothing in the Library,’ Kai said hopefully. He had much better taste in clothing than Irene did, and frequently exercised it.

‘Time,’ Irene said. ‘I’d rather get back here as soon as we can. We can collect any mail in the Library, but other than that . . .’ She shrugged. ‘We’ve been away from here for nearly a fortnight. As Librarian-in-Residence, it’s my duty to make sure nothing’s happened in our absence.’

‘Li Ming and Vale will both be glad to know we have returned, too,’ Kai agreed. ‘As you say, then.’

Irene led the way down the stairs and passageways at a fast walk, ignoring the looks of surprise, shock and sheer horror. Ladies in this world did not wear trousers. Zeppelin pilots and engineers did, but they weren’t generally ladies, and they wouldn’t go wandering around the British Library in them.

The room containing the permanent entrance to the Library was cordoned off with ropes and signs, declaring hopefully REPAIRS IN PROGRESS. Irene had to admit to a certain responsibility there, involving a small fire and a pack of werewolves, but on the positive side, it did make it easy for the two of them to march in while looking like workmen.