Anyone with a Hogwarts-shaped hole in their lives can't miss the third book and final showdown in this fantasy series. Return to Lundinor, the underground city that holds the world's greatest treasures . . . and its biggest threats."Part Tim Burton, part J. K. Rowling! A terrific series." --Soman Chainani, New York Times bestselling author of the School for Good and Evil seriesAfter years of searching, Ivy gets word that her best friend Valian's long-missing sister Rosie may