While transporting a car from Chicago to San Diego, Jim Halsey (C. Thomas Howell) picks up a hitchhiker named John Ryder (Rutger Hauer), who claims to be a serial killer. After a daring escape, Jim hopes to never see Ryder again. But when he witnesses the hitchhiker murdering an entire family, Jim pursues Ryder with the help of truck-stop waitress Nash (Jennifer Jason Leigh).