In order to write a book about serial killers, yuppie writer Brian Cather (David Duchovny) and his photographer girlfriend Carly (Michelle Forbes) plan to take California as their destination and revisit the famous killer route in the United States. On the way, Brian picked up a pair of young lovers, Earle (Brad Pitt) and Alice (Juliette Lewis) to share the expensive fuel costs, but Carly always had doubts about these two sloppy and lazy young people. Sure enough, as the journey unfolded, the careful Carly discovered through various clues that the young couple was not as simple as it seemed, and there seemed to be some unknown secrets behind them. The two people who followed the killer's footsteps for thousands of miles did not realize that the real killer was lurking beside them...