Claire wakes one day to find herself chained in a basement. Her horror is amplified when she discovers that her captor is her own mother. Helen assures Claire that the situation is necessary and "for her own good." And to add to Claire's terror, in the days and nights to follow she is beset by strange apparitions and frightening experiences, finding herself precariously balanced on a razor's edge between reality and insanity, and ultimately forced to face a dark truth.