Bob Holliday (Broderick Crawford), owner of the Bella Union saloon in Deadwood, sends his younger brother, Jim Holliday (Robert Stack), to St. Louis, Missouri to escort back Anne Grayson (Ann Rutherford), Bob's childhood sweetheart. On the riverboat journey back to Deadwood, Jim and Anne fall in love and are married by the riverboat captain. Whe Bob learns of this he is outraged and goes on a drunken binge and is beat up by the ruthless Jack McCall (Lon Chaney, Jr.) and is saved by a teamster called and known only as Jane (Frances Farmer). She loves Bob and has thought she and Bob would get married. Bitter Bob joins McCall's renegades who, disguised as Indians, rob the stagecoach gold shipments , aided by information supplied by Ransome (Bradley Page), the local agent for the stagecoach line. To end the lawlessness, leading citizens of the town decide to hire a town marshal. When Wild Bill Hickok, turns down the job, Bob suggests that the unqualified Jim be given the job. Bob thinks that Jim will be humiliated and possibly killed, so he can marry Jim's widow. With timely interference by Hickok, Jim arrests McCall but he escapes. And Jane makes an unsuccessful attempt to stop Bob riding with the renegades. Jim has a plan to capture the outlaws by having a posse follow the stagecoach, but it goes awry but Jim finds a watch-fob belonging to Bob. The latter claims he lost it when McCall beat him up. Jim buys his exclamation. Meanwhile McCall murders Hickok and Jim is going after him but is stopped when Jane warns the town that, based on smoke signals, it is about to be attacked by the Sioux. Jim sends stagecoach driver, Hurricane Harry (Fuzzy Knight), to bring General Custer (Addison Richards) and his 7th Cavalry troopers. The Sioux attack and set fire to the town, while Bob and McCall and the gang members, disguised as Indians and under cover of the attack, plan to rob the bank.