“What the hell?” Eliot said. He seemed if anything more surprised than she was.

The pool was sunk level with a marble floor. Water trickled into it from the open mouth of an angry stone face at one end; at the other end steps led up and out like a Roman bath, blue water graduating stair by stair up to clear. They stroked over to them in sync.

“This isn’t right,” Eliot said. “This isn’t the Neitherlands, I don’t think. We’ve been hijacked. Button-jacked.”

Magic water streamed out of their clothes as they climbed out, leaving them instantly dry. Awesome. The walls of the room were covered in bookshelves.

“Who puts a fountain in the middle of a library?” Plum said. “It can’t be good for the books.”

“No. It can’t.”

It was a library, maybe the grandest one Plum had ever seen. She would have known it was a library with her eyes shut: the hush of it was enough, like a velvet nest in which she’d been carefully nestled, and the smell, the heavy spicy aroma of slowly, imperceptibly decomposing leather and paper, of hundreds of tons of dry ink. Every square foot of the walls was bookshelves, and every foot of every shelf was full. Creamy spines, leather spines, knobby and ribbed spines, jacketed and bare, gilded and plain, blank spines and spines crammed with text and ornament. Some were as thin as magazines, some were wider than they were tall.

She ran her fingers along them, one after the other, as if they were the long back of some giant, friendly vertebrate that she was petting. In three or four places a book had been taken down and the one next to it was left slightly aslant, leaning its head against its fellow, as if in silent mourning for its absent neighbor.

Even the beams and buttresses had been fitted with shelves—rows and arches and fans of books. In the corners of the room, up near the ceiling, there were little book-sized doors like cat doors. As she watched one of them swung open with a squeak and a book came through, floating in midair, sailed the length of the room, and left through a cat door on the other side.

“I take it back,” Eliot said. “I think this must be one of the libraries of the Neitherlands. I’ve never been inside one.”

“I thought normal people weren’t supposed to be allowed in them.”

“You’re not.”