Acclaimed director John Carpenter makes his long awaited return to the screen with a thriller about a young woman in a 1960s mental institution who becomes terrorized by malevolent unseen forces. Kristen, a beautiful but troubled young woman, finds herself bruised, cut, drugged with laughing gas. 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.