Howard Keel, Yvonne De Carlo, John Ireland, Marilyn Maxwell, Scott Brady, Brian Donlevy, Barton MacLane, James Craig, & Roy Rogers, Jr. as Roy. A Confederate prisoner of war takes advantage of an opportunity to enlist in the Union army and patrol the Western territories. Narrated by James Cagney.

Lee Travis, a captured Confederate riverboat gambler and gunfighter, is given the opportunity to join the Union Army and help bring law and order to the West. When residents of Colton, Arizona, learn that a turncoat is going to replace Sheriff Grover, everyone complains except Mayor Joe Smith. He hopes that Travis can help rout Tom Rile, who has been bribing the corrupt Grover; in truth, however, Travis is a Southern spy assigned to transport arms and ammunition hidden near the town to a group of Confederate soldiers. Hoping to rid the town of the drunks and bums hanging around Rile's saloon and gambling house, Travis wins the saloon from Rile in a dice game, then closes the place and orders Rile out of town. Travis learns from bar girl Molly, whom he has mistaken for his Confederate contact, that Rile has been selling weapons to Apaches. Realizing that Rile has been availing himself of the hidden Confederate supplies, Travis tries to apprehend him but is shot and taken to a doctor by milliner Jill Wyler, who, he has learned, is his contact. In the meantime, Dan Shelby, Grover's deputy, discovers that Travis and Jill are spies and is about to turn them over to Mayor Smith when Grover returns to announce that the war is over. The ex-sheriff also informs the mayor that Rile and the Indians are about to attack the town. The small band of citizens defend themselves against the raid, killing Rile, his gunmen, and most of the Apaches. Jill and Shelby are romantically united, and Travis gives Molly the deed to the saloon before riding out of town.