After a mysterious serial killer named Mr. Frost (Jeff Goldblum) confesses to the murder of two dozen people in England, he is shuttled around psychiatric hospitals throughout Europe as topnotch shrinks attempt to penetrate his psyche and discover why there are no known records of his existence. During this two-year period he refuses to speak to anyone until he arrives at a French facility, where he finally opens up to Dr. Sarah Day (Kathy Baker), who becomes intrigued by his insistence that he is the devil. Throughout their various confrontations, the duo debate the nature of good versus evil and science versus spirituality. While Dr. Day is skeptical, she begins to wonder about Mr. Frost's true identity as he seemingly exerts a psychic influence on the staff and patients of the facility. Meanwhile, Felix Detwiler (Alan Bates), the cop who prosecuted Frost's case tries to warn the doctor of Frost's mesmerizing powers, afraid he is trying to take control of her. If her patient is the devil, what can Sarah do?
