The bridge spanned a vast, round tower. On either side of Lenora, two soaring walls of books curved around to meet again in the distance, on the faraway end of the bridge. All along the walls were hundreds of those rolling ladders people use to reach tall bookshelves. The ladders clacked and squeaked, sliding along busily, with librarians climbing up and down them and plucking books from the shelves or putting them back. They were coming in and out of doors, thousands of doors, set in stone walls between the unending shelves. Here and there were broad balconies with librarians hurrying along past circular windows the size of Ferris wheels, their arms full of books. None of them took any notice of Lenora as she gazed at all this in astonishment.

She threw back her head. The shelves rose higher than the eye could see. Sunlight beamed in from more giant windows set haphazardly in the walls. There were more bridges, too, like the one she was on, arching gracefully between the walls in all directions. She could see round shapes floating past the shelves, too far away to make out exactly, but they reminded her of balloons.

Gathering herself, she trotted to a railing and leaned over to look down. There was no end to the walls below, either, but she could see more stone bridges, down and down, with specks crossing the lowest ones that must be other people. She staggered back dizzily as a blimp rose into view, with an elegant wooden cabin attached beneath. Through its portholes she could see it was full of bookshelves, too. A librarian navigated the blimp by a wheel like a sailing ship’s mounted at the helm.

Lenora walked a little farther along the bridge, until she got to a place where she could have a good look through one of the gigantic round windows in the tower’s walls. She saw the outside walls of several more towers—like the one she was in, she supposed—and besides those, the tops of all kinds of other buildings, like pyramids and stately, columned edifices that looked like … like … well, she couldn’t recall the name, but it was a building on a hill in Greece. All these were closely connected by bridges and webs of strange glass tubes through which dark shapes—she couldn’t tell what from this far away—sped along.

She was trying to make sense of this startling view when motion at the other end of the bridge caught her eye. A thin, very tall librarian with dark skin was striding through the opposite archway. The woman came swiftly toward Lenora and soon was towering over her. “You!” the woman said, pointing down. “You are not allowed in this part of the library!”