Irene considered and rejected all the arguments that started There’s more to it than just stealing books. ‘Because you’d have to swear yourself to the Library,’ she said. ‘Permanently, full-time, life and death. Would you actually do that, Zayanna?’

Zayanna laughed, but there was something a little forced about the sound, and Irene couldn’t see her face. ‘How true, darling! I’m just a frivolous, self-obsessed little mayfly. How well you know me.’

Part of Irene wanted to kick herself for saying the wrong thing, while depending on Zayanna to lead her to Alberich’s sphere. Another part felt unreasonably guilty. She’s admitted to working for Alberich and against us, to trying to kill me and Kai, and I’m embarrassed because I hurt her feelings. This is neither logical nor intelligent. ‘I’m sorry,’ she said. Whether or not Zayanna deserved an apology, it felt like a good idea to give one. She couldn’t afford to have the other woman turn against her now. ‘I know you were just doing your job. And I’m sorry for branding you. It was the only way I could think of to save your life.’

Zayanna rubbed at the angry burn on her neck. ‘Try and be more artistic about it next time, darling. That’s all I ask.’

For a while they walked in silence. Irene wanted to go faster, but Zayanna was the one setting the pace. The Fae’s steps had grown slower, and she forced herself forward as though she was struggling against a high wind. The air was thick and close, like the end of summer, full of dust and smelling of dry grass and overripe fruits. Zayanna’s face was marked with sweat, and she pushed her hair back from her face with her free hand, muttering a curse.

‘Can I help?’ Irene asked, breaking the silence.

‘No.’ Zayanna sounded as if she was in the middle of running a marathon. ‘Told you it was going to be difficult to bring someone else along. Just keep on walking. Keep on going.’

The walls on either side were red-brick now, and the two women had to turn sideways to squeeze between them. Beyond the walls Irene thought she could hear the sounds of machinery, great pumping presses and turning gears.

Zayanna stopped, and Irene went up on her toes, peering over her shoulder to see what lay ahead. She saw a small door set into the wall, unobtrusive and constructed of plain metal, looking positively unimportant. An incongruous letter-flap was set into it.

‘Ah,’ Zayanna said. ‘Here we are.’ She opened the door before Irene could stop her.

CHAPTER TWENTY-FOUR

It was something of an anticlimax to find the space beyond the door full of bricks. They were cemented in place, and even dusted with cobwebs in places. For all that Irene could tell, the doorway might have been bricked up for decades.

‘It wasn’t like that before,’ Zayanna said. She tilted her head to look at it from another angle, but that didn’t make the bricks miraculously disappear.

‘Is this where anyone trying to get to this sphere would arrive?’ Irene asked. ‘Or is it just that you used this door last time, and so you came here again?’

‘Not exactly, darling.’ Zayanna rubbed her nose thoughtfully. ‘It’s more as if this sphere is like a carriage in motion, and we’re running alongside and trying to jump on, and this is the point where you can scramble into the carriage from the road. I know that’s a really bad simile – or is it a metaphor?’

‘It’s a simile,’ Irene said, glad of a question she could actually answer. ‘You said “like”.’

‘Simile, right,’ Zayanna said. ‘But that’s basically how it is. This is how anyone would get in, if they tried to reach it the way I just did. It does look rather as if Alberich doesn’t want visitors.’ Implicit in her tone was a suggestion that perhaps now that she and Irene had made the effort, they could turn around and leave, with honour satisfied.

‘And the letterbox? Was that there before?’

Zayanna nodded. ‘It was there so we could pass urgent information to him.’

‘Like what I was doing – yes, quite. And it’s a reasonable supposition that he wouldn’t want Librarians getting in here, either,’ Irene said, thinking out loud. ‘So if I were him, I’d booby-trap it against someone using the Language, in case one of us told the bricks to get out of the way.’

‘He’s not really giving us much of a chance,’ Zayanna said unhelpfully. ‘How are we supposed to get in there?’

‘But he doesn’t want us getting in there . . .’ Irene started, then paused. Alberich had hijacked a high-chaos world. In high-chaos worlds, stories came true. No narrative would ever finish with And so the protagonist shut himself up in a convenient castle until his plan came to fruition – tale over. He could brick up doors and lay traps, but in any classic story the intruder would eventually enter the castle. ‘Are we in a high-chaos area at the moment, ourselves?’

Zayanna wobbled her hand. ‘Fairly. Quite a bit. Not as much as Venice was, but more than that world you were living in. There’s a strong gradient between this sphere we’re in at the moment and the one through that door.’

‘Do you think we could get through the wall at any point other than that door?’ Irene asked.

‘No.’ Zayanna was quite definite. ‘At least, not by any way I know.’

Irene nodded. ‘All right. We need to stand well back.’

Zayanna looked alarmed but interested. ‘What are you going to do, darling?’