The Great Library is a twenty-three story building divided into four wings (north, south, east, and west). Each level has book stacks and private study rooms. The books are marked with a single identifying number determined by the order in which they were acquired. They are shelved in this order, too, with lower numbers on higher levels and higher numbers on lower levels.
The Catalog is a large book permanently affixed to a large ruby pedestal. It is a semi-sentient being that understands any spoken language and communicates by magical writing appearing on its pages. Anyone can use the Catalog. It can find any book by author, title, or subject matter. It also has records of every book and when and by whom every book was searched for or checked out, though it does not always share those records.