Frank Cooper, a senior immigration police, remains a daily struggle against mafias operating between Mexico and the United States. Although it has a good standing with the poorest of Mexican towns near the border. Two are Leina and Benny, a couple of young boys who have decided to marry and have chosen Frank as best man. The problems are not slow to appear when Suarez, a mobster local forces Benny to work for him in their dirty business. Now, for Frank, the job becomes personal.

Karl Westover, an inexperienced farm boy, runs away after unintentionally killing a neighbor, whose family pursues him for vengeance. He meets Barbarosa, a gunman of near-mythical proportions, who is himself in danger from his father-in-law Don Braulio, a wealthy Mexican rancher. Don Braulio wants Barbarosa dead for marrying his daughter against the father's will. Barbarosa reluctantly takes the clumsy Karl on as a partner, as both of them look to survive the forces lining up against them.