Beautiful girl Rebecca (Sarah Berg Sarah Bolger) is a girl's church boarding school student, cheerful and enthusiastic she made a lot of good friends at school, of which the blonde girl Lucy (Sarah Gordon Sarah Gadon) has the most harmonious relationship. The two are inseparable, say everything and are close to each other. At the beginning of the new semester, the tall and gorgeous Enissa (Lily Cole Lily Cole) is transferred to their school. Rebecca was uncomfortable with Ennessa's seductive mystery, but Lucy seemed to like it, and the two got closer and closer. At the same time, Enissa seems to evoke the unbearable memories of Rebecca. What kind of secret does the woman who seems to come out of the Gothic horror novel hide? This film is based on the best-selling science fiction horror novel of the same name Rachel Klein.