When fifteen-year-old Leah Ackerman witnesses her father murder her mother, she discovers a terrifying truth: he's been possessed by a demon. Now orphaned and grappling with newfound magical abilities, Leah is thrown into a hidden world of supernatural warfare. Taken to a remote outpost by her estranged uncle, she must learn to control her dangerous powers while training with other young mystics. As she uncovers her mother's secret past as an elite demon hunter, Leah realizes the demon that destroyed her family isn't finished with her yet.