Kristen (Amber Heard), a beautiful but troubled young woman, finds herself bruised, cut, drugged, and held against her will in a remote ward of a psychiatric hospital. She is completely disoriented, with no idea why she was brought to this place and no memory of her life before being admitted. All she knows is that she isn't safe.
The other patients in the ward--four equally disturbed young women--offer no answers, and Kristen quickly realizes things are not as they seem. The air is heavy with secrets, and at night, when the hospital is dark and foreboding, she hears strange and frightening sounds. It appears they are not alone.One-by-one, the other girls begin to disappear and Kristen must find a way out of this hellish place before she, too, becomes a victim. As she struggles to escape, she will uncover a truth far more dangerous and horrifying than anyone could have imagined.