Trevor Blackburn (Andras Jones) is a man with no memory of his past. Haunted by nightmares he awakens from a coma to find himself under the care of Dr. Ek (Jeffrey Combs) who informs Trevor that he has been committed to Ek's sanitarium for the sacrificial murder of his fiance.
Trevor is sent to a halfway house to join a group of recovering psychotics overseen by Dr. Abbey Thalama (Wendy Robie). Reality and fantasy converge in Trevor's nightmares - nightmares of his own brain surgery and a strange trunk locked in the attic that conceals the entrance to a mystical infinite space. As Trevor's grip on reality slips, his fellow residents are being murdered and Trevor is the prime suspect. Trevor's paranoia increases with the body count and his dead fiancÈe Faith (Beth Bates), reappears to him in his waking life and threatens to possess a fellow resident and kill him. Behind it all, Dr. Ek watches his experiment, to plot Trevor's fate -complete insanity, to the horror of the visiting Dr. Coffee (Ted Raimi).