"It had become a chimney poking from a vertical universe of bookshelves.

There was motion below her. There were people on the shelves.

They clung to the edges of the cases and moved across them in expert scuttles. They wore ropes and hooks and carried picks on which they sometimes hung. Dangling from straps they carried notebooks, pens, magnifying glasses, ink pads, and stamps.

The men and women took books from the shelves as they went, checked their details, leaning against their ropes, replaced them, pulled out little pads and made notes, sometimes carried the books with them to another place and reshelved it there.

...

"I'm Margarita Staples." She bowed in her harness. 'Extreme librarian. Bookaneer.' "
— China Miéville