The activities of a bandit, known as "The Fox" and working out of Mexico, rouses the Texas Rangers into action. Rankin, head of the Rangers, decides upon a ruse. Texas Ranger "Hopalong" Cassidy is to submit himself to arrest after means have been taken to ruin his reputation as an honest lawman and force him from the Rangers. As an outcast, he is to go to El Rio, headquarters of the "Fox" gang and try to contact the bandit, Cassidy agrees and leaves, much to the dismay of fellow-Ranger Johnny Nelson, who isn't in on the scheme. In El Rio, Cassidy, after snubbing his old friend, "Windy" Halliday, takes up with the town's riffraff, which includes "Loco," a half-wit. Through an emissary, Loco overhears "Windy" tell young Molly Rand that he thinks Cassidy is putting on an act. This leads the pair to be kidnapped and held hostage by "The Fox" in case Cassidy gets too close to finding out his true identity.
—Les Adams <longhorn1939@suddenlink.net>