Concerned for his autistic daughter's health, a father sees her removal from the hospital by force as the only option. An elevator break-down prevents a smooth exit and renders them trapped with others. Yet the incident is only the beginning of the nightmare. As the doors open the hospital appears mysteriously deserted. When mutilated bodies are found, creatures from a dark world start a frightening attack. It soon becomes clear that the survival of the group may rest solely on the little girl.