Italian journalist Walter Mancini (Franco Nero) and his American wife, Eve (Corinne Clery), are on a camping vacation Nevada, but all they do is bicker and have angry, punishing sex. Eve complains that Walter drinks too much, Walter resents the fact that Eve's father is his boss, and during a sordid, drunken scene at the communal campsite, Walter drunkenly stumbles over another camper's tent line and breaks his hand. The following day they begin the drive back to Los Angeles, towing their comfortable caravan. Ignoring Walter's warnings, Eve picks up a hitchhiker, Adam (David Hess), who almost immediately establishes himself as a boor. Walter tries to throw him out after an obscene remark about Eve, at which point Adam reveals that he's one of a trio of thieves who pulled off a bloody robbery in nearby Barstow and killed a cop in the process. Adam has the money — $2 million in a battered suitcase — and if he's going to get past the police roadblocks, he needs the Mancinis to drive him to Mexico.....