Sarah is an autistic little girl whose father is worried about her health. Concerned for her, the father sees her removal from the hospital by force as the only option. An elevator breakdown prevents a smooth exit and leaves them trapped with others. Yet the incident is only the beginning of a descent into 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.