The film follows the story of Michael Jones, a mental patient at Brookhaven Hospital, as he undergoes psychotherapy sessions with his psychiatrist Dr. Elizabeth Harvey. Much of the story takes place within Michael's mind, which is somehow linked to the Otherworld due to his psychosis. Scenes that take place within the Otherworld often appear more "real" than those that take place in the Real World, indicating Michael's tenuous connection to reality. Michael's descent through the layers of the Otherworld are often visualized by a swiftly falling, cage-like elevator in which he is trapped. Ever-present is a dark, demonic form that seems to be stalking him.
