Two cowboys fight to protect a jewel shipment slated to help Mexican earthquake victims.

After an earthquake devastates northern Mexico, a relief expedition, consisting of goods, jewels and money, is organized in Arizona by wealthy Mexican-American rancher Anita Castro. Just before the expedition is to leave, Rod, a slick outlaw, poses as a concerned contributor in order to gather information about Anita's plans. Rod reports his findings to saloon owner Bat, who plots to rob the expedition before it crosses the border. At the same time, cowboys Ed Porter and Chito Rafferty ride into town looking for work. After ladies man Chito is snubbed by Rod's girl friend, saloon singer Stella, he and Ed are hired to mend fences on the range. Anita and her major domo, Felipe, meanwhile, see Dimmick, one of Bat's henchmen, spying on the expedition's mule train and fire warning shots at him. Chito hears the gunshots and rides to investigate, while Dimmick races back to town to tell Bat the train's location. Later, on the range, a masked Bat mistakes the passing Chito for an expedition member and holds him at gunpoint until Rod, who has spotted the mule train, corrects his error. To protect the train, which is now hiding among some rocks, Felipe deliberately rides by the gang, who shoot and capture him. As Bat tries to whip Felipe into revealing the train's hiding place, Chito and Ed ride up and begin firing on the gang. After the cowboys drive off the outlaws and deliver the wounded Felipe to a nearby mission, they go to town to find Sheriff Kerrigan. Unable to locate the sheriff, Ed and Chito visit the saloon, where Chito recognizes a ring on Bat's finger and accuses him of the attack. Bat then engages Ed in a fistfight, which finally ends with the arrival of the sheriff. Bat is arrested, and Rod assumes control of the gang. Ed and Chito, meanwhile, return to the range to hunt for the mule train and are fired upon by Anita. Ed soon out-manuevers Anita and convinces her to keep the train hidden until the next morning. Ed then instructs Chito, who is smitten with Anita, to ride to town and tell the sheriff where the train is hiding. The sheriff is unavailable, however, so Chito writes the location down for Pokey, the dimwitted deputy, unaware that Stella is watching him. The next morning, Stella, who stole the paper away from Pokey, Rod and his gang, wait near the rocks for the expedition to pass. To draw Ed and Chito away from the train, Stella pretends to lose control of her buggy and races by, screaming for help. Then, while the cowboys are busy rescuing her, Rod and his men rob the train, causing Anita to accuse Ed and Chito of betraying her. Eager to clear themselves, Ed and Chito go to town to question Stella. Just outside the saloon, Chito overhears Stella and Rod discussing a diamond necklace that was part of the relief package. Ed then sneaks into Stella's room to search for the necklace and becomes entangled in a fight when she unexpectedly returns. As Bat and his men fire on them, Ed and Chito flee the saloon with the necklace and return it to Anita at the mission. Having convinced Anita of their innocence, Ed and Chito connive to have Bat escape from jail and follow him to the gang's hideout. While Chito rides back to town to alert the sheriff, Ed stays at the hideout. There Bat confronts Rod at gunpoint and demands his cut. As he is collecting the booty, however, Stella sees Ed outside and warns the gang. Ed and the gang exchange gunfire, and during the confusion, Rod tries to escape with Stella but is shot down by Bat. After the sheriff and his posse arrive with Chito, Bat and his gang are apprehended, and Ed outdraws Stella. Later, at the border, Ed and Chito say goodbye to Anita and return to their cowboy existence.