In 1870s New Mexico, Tom Herrera, the head of the Tonto Valley Wells Fargo stagecoach station, prepares to defend against an attack by an Apache war party seeking revenge for the cold-blooded slaughter of several Indians by an outsider. As distant smoke signals warn of the impending attack, a stagecoach arrives at the station with passengers Nancy Dekker, the daughter of a U.S. Cavalry major, Wells Fargo home office representative Cyril R. Snowden, Tom's old flame, Lorraine Sayburn, and Fanny Webson, a thrill-seeking gambling queen posing as a New England matron. The passengers, along with the stagecoach driver, become stranded at the station with Tom and his bandit father Peso. Peso, the "most sought after feller in the Southwest," is after gold contained in the casket of the stagecoach, and Tom, knowing this, takes his father's guns as a precaution. Tom is not pleased to see Lorraine, whom he no longer loves, but she manages to coax a kiss from him. Witnessing the kiss, Nancy, who has fallen instantly in love with Tom, becomes jealous. As the Apaches, under the command of Geronimo, begin their attack, suspicion is immediately cast on Peso as the source of the Apache rage. Tom and Fanny are the only ones at the station who come to Peso's defense when others suggest the bandit be turned over to the Indians to bring a speedy end to the conflict. Though Snowden threatens to report Tom's stubbornness, the station head eventually wins out, and Peso stays. With the help of Fanny, who idolizes the notorious bandit and gives her guns to him, Peso holds up Tom and the others and demands that they hand over the casket. Tom, however, outdraws his father and shoots the gun out of his hand. Despite the robbery attempt, Tom continues to believe that his father is not responsible for the war party. A fierce battle ensues between the Apaches and those trapped inside the station, resulting in the death of Major Dekker. During a lull in the fighting, an Apache emissary tries to negotiate for the surrender of the murderer, but Tom again refuses to turn his father out, and the fighting resumes. During the battle, Peso knocks out Pike Curtis, a local man who Peso knows is the killer, and turns him over to the Indians. With all doubt about his father's trustworthiness removed, Tom bids Peso farewell as he joins Fanny on her journey to San Francisco. As the stagecoach fades into the horizon, Nancy, who has remained behind to marry Tom, informs him that the gold is not as secure as he thinks, because Luis, the young boy assigned to guard the treasure, is actually another one of Peso's sons.
