Amy is an elementary school teacher who suffers from nightmares about doctors and hospitals, stemming from the circumstances of her father's death. On the afternoon of the day he proposed, Amy and her fiancé Nick are in a serious car accident. An ambulance takes Nick away without telling Amy which hospital they are going to. Amy and Lucas, the driver of the truck that hit them, try to find where Nick and Lucas' sister have been taken. Amy begins to hallucinate, seeing disfigured faces, including her own in a mirror. A little girl in her class, Melissa, claims she can help Amy find Nick, and gives Amy the name of St. Rosemary's Hospital. Amy and Lucas learn that St. Rosemary's, which was rumored to be the home of devil worshipers, was destroyed in a fire some 70 years ago, along with all the nurses and staff, who refused to leave. Meanwhile, Nick is having his own strange experiences at St. Rosemary's, such as nurses who spray blood on each other and eat another patient, and a hallway that repeats itself.