The last job of Calvary Captain Nathan Brittles (John Wayne) before retirement is to soothe relations with the Cheyenne and Arapaho Indians after Custer's last stand. At the same time, he must transport the wife (Mildred Natwick) and niece (Joanne Dru) of his commanding officer to a safe destination. After both his missions stall, Brittles attempts a face-to-face meeting with an important Native American chief in order to stave off an impending war.