Patrick Martin (Joseph Cotten), known as P.M., is a wealthy attorney and rancher big-man-in-town in the border town of Nogales, Arizona. He returns home to find his brother Donald (Van Johnson)hiding in his garage. A former drunkard, Donald had been sent to the penitentiary five years previously for killing a man in a barroom brawl. It was in self-defense but P.M. hadn't defended his brother and he was convicted. Donald has escaped and wants his brother to help him across the Santa Cruz River into the Mexico-side Nogales, where his wife (Shirley Patterson as Shawn Smith)and children (Kim Charney and Sandy Deschler) are in dire straits. The straits get even dier when P.M. tells him the river is flooded and it will be days before anyone can cross. And P.M. is all a'twitter because his wife Nora (Ruth Roman), whom he married after Donald had gone to prison, doesn't know about his jail-bird brother.