Effie blushed when she remembered how self-important she must have sounded before when she’d stepped forward and introduced herself.

“Yes,” she said. “But it’s not—”

The librarian sighed. “I’ve heard your name in the prophecies.” He frowned. “Aren’t you due to save the world today?” He peered at Effie more closely, as if trying to work out whether or not to let her off a large library fine. “I’m not sure I care if I’m saved or not. But other people probably do. All right. Come on.” He creaked himself out of his chair. “Warrior cleric’s prayers, you say. Pretty specific. And you’re clearly not a warrior or a cleric. . . .”

Effie followed him into the part of the library where Lexy and Raven had gone last time, with all the tall, dusty stacks. He carried on muttering to himself as he peered at the numbers on the shelves, none of which seemed to have any logic to them at all.

“Aha,” he said, and started to unwind a stack with a creaky brass lever. “Here we go.” He unwound the shelves until there was just barely enough space for him to squeeze in. He plucked the book from the shelf quickly, as if he was taking it from the cage of some ferocious animal. And then he gave it to Effie as if it was contaminated.

“There you go,” he said. “Take it away. Take all the blooming—”

“Thank you,” said Effie. “Do you also have a book on the Flow?” she asked him.

“The what?”

“The Flow. It’s like a magical current that you—”

“Shhh,” said the librarian. “No spoilers! No spoilers! Not so blooming loud. You’re not supposed to speak of it to those who don’t know.”

“But you obviously do know.”

“Well, I do now.”

This was confusing Effie.

Nevertheless, the librarian had set off in the direction of the Otherworld section, muttering as he went.

“You’d better not ask me for anything else after this,” he said. “Ever. Right. The Flow. The Flow.” He reached to get the book from the shelf but it must have been mis-shelved or something, because he didn’t pull it out straight away. He scrabbled around for a while but then came back empty-handed.

“Oh,” he said. “Oh dear. I forgot. It’s on loan. Never mind. Come back next week if you like, once we reopen after the world ends.”

“You only have one book on the Flow?”

“Yes, and that’s generous, considering what a big secret it’s supposed to be. But it’s the classic hypergeographic study of Thomas Lumas. Only book on the subject you’ll ever need. But anyway, like I say: It’s on loan.”

“Who to?”

“To whom,” corrected the librarian.

“Please,” said Effie. “The end of the world doesn’t care about my grammar. Who has the book?”

“That Diberi woman,” said the librarian. “The Russian one. The poet.”