The Apache chief Geronimo is on the loose in the territory. In Tonto, a motley group of passengers board a stagecoach headed for Lordsburg. Buck, an affable if silly driver, takes the reins beside Marshal Curley Wilcox. In Tonto, Doc Boone, an alcoholic doctor, is being kicked out of town for his incompetence, along with a local prostitute, Dallas, and they both get on the stagecoach to Lordsburg, along with an exceedingly polite whiskey salesman, Mr. Peacock, and a corrupt banker, Gatewood, who is making off with a large sum of cash. Also aboard is Lucy Mallory, a wealthy Southern woman who is traveling while pregnant to visit her husband, who is a soldier stationed in Lordsburg. Looking to protect the fragile Mallory on the trip is Hatfield, a former Confederate soldier and disingenuous gambler.
On the way to their first destination, the stagecoach encounters the Ringo Kid, an outlaw who has recently escaped from prison in order to avenge the death of his father and brother, who were killed by the evil Plummer brothers. Ringo was sent to prison falsely, but Curley arrests him and he joins the group on the stagecoach. When they arrive at their next stop, there are no cavalry troops to bring them along their way, but the passengers vote to keep going towards Lordsburg alone.
When they reach the next stop, Lucy Mallory learns that her husband has been taken to a new location, and she promptly falls ill and has her baby prematurely. Doc Boone sobers up and delivers the baby, and Dallas dutifully looks after it. Dallas and Ringo fall in love and he proposes that she come live with him at his ranch across the border. Dallas does not accept, worried that once Ringo finds out she is a prostitute, he will not want to be with her. Later, she encourages Ringo to escape Curley's watch and flee to his cabin, where she will meet him at some other point. As he leaves, he sees an Apache war signal and stays with the group. They hastily make their way to Lordsburg, but on the way are set upon by Apache warriors. Peacock is wounded and Hatfield dies. At the last moment, just when it seems that all hope is lost, the cavalry troops show up and save the day, and the stagecoach makes it to Lordsburg.
In Lordsburg, Gatewood is arrested for embezzling money, and Lucy and her baby are brought to safety. Ringo has a dramatic shootout with the Plummer brothers, successfully killing all three even though he is outnumbered. Afterwards, Curley gives him his freedom and he rides off to his ranch with Dallas to live in domestic bliss.
