O'Hara realizes that Vickers suspects him to be one of the killers of his fiancée. An ambush attempt fails, so he deserts the Army and flees. A wagon train is formed to evacuate civilians while Custer prepares to do battle at Little Big Horn, but along the way, Molly, her father and Vickers are taken captive. O'Hara is a prisoner, too, and when he learns Custer's men will be hopelessly outnumbered and slaughtered, he tries to go warn the general and sacrifices his own life, distracting the Sioux until the others can escape.