U.S. Marshal Noah Randall of New Mexico Territory is in pursuit of four outlaws, they call themselves the Slater Gang. Gus Slater is the ring leader along with brother Clyde and two other members. They are all considered to be ruthless killers. The gang holds up a Santa Fe train just outside Las Cruces, New Mexico. Shooting two men and assaulting the conductor.

The marshal goes in search of the outlaw gang only to discover they have likely fled across the border into Mexico? He has no jurisdiction there, but he is determined to track them down and bring them back to New Mexico for justice to be served.

His search takes him into Mexico, there he stops at a Mexican Mission where he befriends a padre. With no place to stay, the padre offers him a room to sleep in the church. While there, he resumes his search for the four outlaws. He removes his badge to hide his identity as a lawman. He visits several of the surrounding cattle ranches to see if they might be hiding out at one of ranches, Using the pretense of looking for a job.

While rooming at the church, he meets a young fellow, who was the church's handyman. Also, a mother and daughter who run a small cafe behind the cantina. He senses the handyman is sweet on the cafe owners, daughter. The marshal is a newly married man himself and is missing his wife back in Las Cruces. He notices a budding romance between the handyman and the cafe owner's young daughter.

He soon learns the Spanish Mission is a haven for rowdy drunks, and men who have run afoul of the law. As he continues his search for the four outlaws, he encounters many twists and turns in his pursuit of justice, and many surprises along the way.