Walter (Franco Nero) and Eve (Corinne Clery) Mancini are a couple on a road trip in the western USA. They argue and fight the whole way. Eve stops to pick up a hitch hiker (David Hess). The hitch hiker turns out to be a psychopathic killer, escaping from a bank robbery with $2 million in a briefcase. He forces them at gunpoint to drive him to the Mexican border. Along the way, the hitch hiker shoots 2 cops who pull them over. His 2 accomplices from the bank robbery catch up with them. However, the hitch hiker kills them, too. The hitch hiker ties up Walter, leaving Walter to watch as the hitch hiker rapes Eve. The hitch hiker is ignoring Eve as he is about to kill Walter. Eve shoots and kills the hitch hiker with Walter’s rifle.
Eve wants to immediately call the police. Walter insists they are keeping the money. Walter hides the hitch hiker’s body in their camping trailer. Later, as Walter and Eve are driving, 4 bikers force them off the road. Their car flips over. The bikers reach in and take $300 from Walter’s pocket, but leave the briefcase with $2million. Walter is able to get out, but Eve is pinned in the overturned car. Walter tells her that the bikers actually helped him. His plan was to kill Eve and keep all the money, and the bikers have made that easier for him. He gets the hitch hiker’s body from the trailer and puts it in the driver’s seat of the car. He flips a lit cigarette into the pool of spilled gas, igniting the car, with is wife who is alive and awake trapped inside to burn. Walter leaves with the $2 million.