An exhilarating and un-put-downable middle grade story from New York Times bestselling and Edgar Award–nominated author Lauren Oliver, about a young girl and her epic quest to find out what happened to her missing father.

Cordelia Clay loves the work she and her father do together: Saving and healing remarkable creatures that other humans might call “monsters.” Their home, Clay Manor, is full to the brim with dragons, squelches, and diggles—and Cordelia loves every one of them.

But one morning, Cordelia awakens to discover that her father has disappeared—along with nearly all the monsters.

With only a handful of clues and a cryptic note to guide her, Cordelia must set off to find out what happened to her father, with the help of her new friend Gregory, a baby dragon, and a small zuppy (zombie puppy, that is).