In the late 19th century American West, lawman Wyatt Earp, who is widely respected for his strong sense of justice and bravery, arrives in the town of Fort Griffin, Texas. Earp is on the trail of an outlaw, but his mission takes an unexpected turn when he meets and befriends John "Doc" Holliday, a charismatic gambler and gunslinger suffering from tuberculosis. Despite their stark differences, Earp and Holliday form a close bond, united by a shared code of honor. Earp, determined to clean up the lawless towns of the West, convinces Holliday to join him as he moves on, setting the stage for their legendary partnership.

Their journey leads them to Tombstone, Arizona, a town under the thumb of the violent Clanton gang. Recognizing the threat to peace and justice, Earp decides to take a stand and bring law and order to Tombstone, with Holliday at his side. The escalating conflict between the Earp brothers, Holliday, and the Clantons inexorably leads to the historic showdown at the O.K. Corral. This confrontation, emblematic of the struggle between lawlessness and justice in the wild West, cements the legacies of Earp and Holliday, as well as the myth of the American frontier.