Jesse James (Brad Pitt), the most famous robber during the Civil War, formed the James Gang with his brother and their minions, and committed countless robberies. Even the best-defended banks could not escape their clutches. Jesse became a legend in the hearts of ordinary people with his superb marksmanship and experience. After middle age, Jesse gradually got tired of the life of wandering and playing hide-and-seek with the government. His minions were either dead or injured, and his brother chose to leave because of Jesse's bad temper. Robert Ford (Casey Affleck), a cowardly boy who had just joined the "James Gang", regarded Jesse as a super idol and lived in seclusion in the countryside with the increasingly tired Jesse. However, after years of getting along, Robert eventually became the one who pulled the plug on the legendary thief's life...