 A thief named Hooper poses as a road construction worker in order to flag down late model cars so that he and his accomplices (Yvonne and Dave) can transport them across the nearby Mexican border to be painted and sold. Since the stolen cars are not turning up anywhere in the U. S., Dan Mathews deduces that they are being sold in Mexico and he enlists the aid of Mexican Highway Patrol Captain Julio Gonzales to set up roadblocks on both sides of the border. When one of the stolen cars is identified, Yvonne is permitted to pass through the roadblock so she can be tailed to their hideout. The thieves suddenly and unexpectedly find themselves in an armed confrontation with Dan, Capt. Gonzales, and their officers.