 Hitchhiker Joe Porter disguises himself, robs drivers who offer him rides, then flees in his own car after meeting his wife Dolly. When he is forced to kill one of his victims, he leaves evidence that enables Dan Mathews to deduce that he and Dolly are traveling cross-country and that he wears actors  makeup while committing his crimes. Desperate for more cash, Joe and Dolly decide to stage an outright armed robbery of a businessman spotted at a roadside diner. A tip from the diner about the "loitering" couple enables Dan to find Dolly waiting in their car while Joe robs the victim. The Porters get away temporarily by using the businessman as a hostage, but they are quickly overtaken by Dan and Sergeant Williams.