Gov. Lubbock (Grandon Rhodes) of Texas has asked Todd Croyden (John Payne (actor)) of the Texas Ranger Division to spring a Union Army spy from a Confederate camp and bring him back. France is trying to seize Mexico and the governor is aiding the latter's defense effort. Guns and ammo are being stolen in Corales, so the governor wants the Ranger and the spy, Whitney Randolph (Dennis O'Keefe), to investigate. Croyden doesn't much care for Randolph, who wins his horse and harmonica gambling on the trail.