The sheriff of a small western town dies of a 'heart attack' (actually shot in the back) and the crooked mayor, The Honorable Hiram J. Sellers (Edgar Buchanan), and leading crook Phil Decker (Lyle Bettger) appoint the town drunk, Reginald T. "Rags" Barnaby (Thomas Mitchell (actor)), as the new sheriff, believing that he will be easily controlled by them. Rags, however, announces he is giving up drinking and refuses to accept Decker as his new deputy, telling them that he has someone else in mind: Tom Destry.