The story follows General George Armstrong Custer's adventures from his West Point days to his death. He defies orders during the Civil War, trains the 7th Cavalry, appeases Chief Crazy Horse and later engages in bloody battle with the Sioux nation.

After Custer's defeat an army captain tries to warn a small town that the Sioux are coming. The inhabitants own two machine-guns but don't want to lend them to him.