Johnny Yuma returns home one year after the war's end to find a gang of thugs have extorted a local mine and murdered his father while his father's deputy and the rest of the town live in fear and despair.

Yuma arrives in a town in which an old friend of his father is sheriff. He learns an advance team of marauders, including the man who killed Yuma's father, has arrived. But none of townspeople, including the sheriff, want to defend the town.