Robert Ryan

When the Clanton gang kills Wyatt Earp's brothers, he decides to go after them and enlists the help of his friend Doc Holliday.

When a flood of lawless gunmen invades his once peaceful town, Marshal Cass Silver knows it's up to him to force them out. But the only chance he might have is to gain the help of a gunslinger named Thad, who wrongly believes the marshal is responsible for his father's death. To save the town, Silver will have to earn the aid, and trust, of a man sworn to send him to his grave!

Outlaws on the U.S.-Mexican border face the march of progress, the Mexican army and a gang of bounty hunters led by a former member as they plan to rob a U.S. Army train.