Farrell is taking advantage of the proximity of the rancho of Don Jose to the Mexican border by smuggling Chinese across the line into the United States. Dave, a border patrol officer posing as a tramp, is out to put an end to Farrell's activities. He is aided by police dog Rinty who gets to growl and show his teeth a lot. Pepita, the Don's daughter, gets to strum her guitar and sing a couple of songs.