A woman, whose car breaks down on the highway, is picked up by a crazed stranger and his obviously threatened girl friend. Despite potential escape opportunities, she stays with the couple who is involved in some kind of unexplained thievery involving a computer disk. After a series of murders, including the girl friend, the woman manages to escape to a scientific lab where time travel is being experimented with. Here she asks to go back in time to try to stop the killings. Repeated attempts results in the same deaths.