 Trampas, a cowhand from Medicine Bow, Wyoming, is sent to Mexico to buy a bull for his employer. The ranch foreman warns him to watch out for himself in Laredo, a tough town on the Texas/Mexican border. Despite the warning, in a western version of the Dumas classic, "The Three Musketeers", Trampas manages to get himself engaged to fight three separate Texas Rangers within an hour of his arrival. Unlike D Artagnan, he has no notion of actually fighting the Rangers: all he wants is out of Laredo. He s on his way out of town when he runs into the three Rangers--who turn out to be partners--on their way to track down a missing train carrying a payroll. The Rangers, learning Trampas is headed in the same direction they are, suggest they all ride together--that way, they can fight him after they have fulfilled their mission. Without much choice, Trampas wryly agrees. When they find the train, however, they quickly forget their quarrels--the train was robbed and everyone aboard killed, except for one infant covered by his mother s body. Concerned the baby won t survive long without care, they proceed across the Rio Grande to the nearest town, where they know of a cantina owner with innumerable children. They get the baby to Mama Dolores, but not without run-ins with Mexican Urales and marauding Yaquis. Somewhere along the way, the Rangers begin to suspect it was the Yaquis who robbed the train--but Yaquis don t rob trains and they have no use for money...and where did they get those fancy new rifles?