"A contemporary Buffy" - Publishers WeeklyThe thrilling and action-packed supernatural mystery from Jennifer Lynn Barnes, no.1 New York Times bestselling author of The Inheritance Games series.Every other day, Kali D'Angelo is a normal sixteen-year-old girl. She goes to public high school. She attends pep rallies (reluctantly). She's human.And every other day in between . . . she's not.Though she's not quite sure what she is on those days, Kali knows what she does . . . she hunts, traps, and kills demons, hellhounds, and other supernatural creatures that threaten her world. On those days, she is practically indestructible.But when Kali notices a mark on a popular girl at school, she knows instantly that the girl is marked for death by one of these unworldly beings. And she knows she has only twenty-four hours to save her.There's only one problem . . . it's the wrong twenty-four hours.