A confederate soldier (Rod Steiger) fires the last shot of the Civil War, injuring a Union lieutenant (Ralph Meeker). Unable to accept the South's defeat, Steiger goes West to live with the Indians, joining the Sioux tribe after enduring their nearly impossible initiation rites - the Run of the Arrow - and continues his fight against the United States. Later, Steiger has to shoot Meeker again, with the very bullet he fired at him at the war's end, but this time it is to save him from torture by his adopted Indian tribe.