A cowhand named Trampas is sent to Mexico to buy a bull, but instead gets himself into a series of fights with three Texas Rangers in Laredo. Despite their initial animosity, they team up to track down a missing train carrying a payroll, only to find it was robbed and everyone killed except for a baby. They take the infant to a cantina owner, Mama Dolores, and encounter Mexican Urales and Yaquis along the way, leading them to suspect the Yaquis were behind the train robbery, despite their lack of interest in money and new rifles.
Backtrack!
A rugged cowboy and gambler ventures into Mexico to capture a prized bull, but instead finds himself teaming up with three Texas Rangers on a perilous cross-border adventure.
