Doc Holliday (Stacy Keach) and Kate Elder (Faye Dunaway) spend time at the Continental Hotel in Tombstone, Arizona, hoping to find his old friend Wyatt Earp (Harris Yulin), deputy marshal of Cochise County, who is striving to become the town’s new sheriff in the election campaign.
Along the way, Doc meets up with Virgil and Morgan Earp, two of Wyatt’s brothers, and follows them to Tombstone. Once Wyatt becomes the sheriff, he and his friend face a fierce resistance from the “Cowboys” gathered around the Clanton family, who want to keep control of the town and don’t accept Earp’s authority. The Cowboys include Ike Clanton (Michael Witney), Tom and Frank McLaury, and Billy Claiborne.
Doc teaches The Kid (Denver John Collins) how to shoot a pistol. When the Civil War ended, he left Atlanta, Georgia and went to Richmond, Virginia and then to Baltimore, Maryland, to be a dentist. After some time he decided to go out to the West, looking for a drier environment to cure his tuberculosis, for which he visits a Chinaman for herbs. (At another point in the movie, he is taking laudanum.)
In the end, the showdown at the OK Corral takes place during a fiesta. John Behan (Richard McKenzie), Wyatt Earp, and Doc Holliday all survive the gunfight. Ike Clanton, Tom and Frank McClaury, and Billy Claiborne do not.