This book follows Elizabeth Scrivener, a curious teenager who grew up among the books and grimoires of her town. Abandoned at the Great Library as a baby, she was raised in the enormous building with the books of magic and mischief. The books are so magical, in fact, that they can even transform into monsters, depending on how powerful they are. Elizabeth is an apprentice librarian when she becomes a suspect in sabotaging the library. Outraged, she teams up with Nathanial Thorn, an insufferable sorcerer who claims he can help clear her name.