The year is 1915 when sixteen-year-old Eliza Williams arrives at the Billings School for Girls in Easton, Connecticut. Her parents expect her to learn the qualities of a graceful, dutiful wife. But Eliza and her housemates have a dangerous secret: They're witches.

After finding a dusty, leather-bound spell book, the Billings Girls form a secret coven. Bonded in sisterhood, they cast spells--cursing their headmistress with laryngitis, brewing potions to bolster their courage before dances, and conjuring beautiful dresses out of old rags. The girls taste freedom and power for the first time, but what starts out as innocent fun turns sinister when one of the spells has an unexpected and deadly consequence.

Magic could bring Eliza everything she's ever wanted...but it could also destroy everything she holds dear.