William Munny is a retired, once-ruthless killer turned gentle widower and hog farmer. To help support his two motherless children, he accepts one last bounty-hunter mission to find the men who brutalized a prostitute. Joined by his former partner and a cocky greenhorn, he takes on a corrupt sheriff.

Legendary marshal Wyatt Earp, now a weary gunfighter, joins his brothers Morgan and Virgil to pursue their collective fortune in the thriving mining town of Tombstone. But Earp is forced to don a badge again and get help from his notorious pal Doc Holliday when a gang of renegade brigands and rustlers begins terrorizing the town.