Undercover agent Mark Owens is sent to aid the Border Patrol in the trans-border town of Hernandez in breaking up a well-organized band of smugglers. Since the town is also noted for a place for obtaining quick marriages on the Mexico side, Mark obtains the job of pilot on "The Honeymoon Express." He does not realize that he has been recognized as a G-Man by "Hot Cake" Joe, operator of a sandwich stand and an informant for the smugglers. Reporter Nancy Rawlings, assigned to the airport on the American side of the border, sees Mike running the matrimonial express in his flamboyant uniform, and thinks he is ridiculous enough to make a good story. Her suspicions are aroused when he refuses to be photographed. She is further convinced he is a smuggler when she sees him accepting money from Kurt Feldon, suspected head of the smugglers. Feldon has accepted Mike as a genuine pilot for wedding parties and is paying him to steer customers to his café. Learning the truth from Joe, Feldon orders his henchman/flyer Blast Reardon to get rid of Mike. Blast, with a gang moll as his accomplice, charters Mike to fly them across the border to get married. A waitress at the airport, who Nancy has bribed to watch Mike's activities, tips her off about the flight and Nancy hides in the plane. Once in the air, Blast forces Mike to land at the smuggler's hideout, where he is imprisoned.