Concerned for his autistic daughter's health, the father sees a 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 a descent into 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.