When a crafty gang of criminals begins using a Rin Tin Tin double to snatch valuable pelts from fox farms, undercover agent Don Brady (Dennis Moore) and his trusty canine companion, Rinty, are called in to track down the baddies and their pooch. But the investigation hits a snag when Rinty is mistaken for the crooks' dog -- and Don is fingered as the fur thief. Luana Walters, Tom London and Jimmy Aubrey also star.