When a 200-year-old witch attacks her, sixteen-year-old bookworm Lainey Styles is determined to find a logical explanation. Even with the impossible staring her in the face, Lainey refuses to believe it—until she finds a photograph linking the witch to her dead mother.

After consulting a psychic, Lainey discovers that she, like her mother, is a Keeper: a witch with the exclusive ability to unlock and wield the Grimoire, a dangerous but powerful spell book. But there’s a problem. The Grimoire has been stolen by a malevolent warlock who is desperate for a spell locked inside it—a spell that would allow him to siphon away the world’s magic.

With the help of her comic-book-loving best friend and an enigmatic but admittedly handsome street fighter, Lainey must leave her life of college prep and studying behind to prepare for the biggest test of all: stealing back the book.