Rex Allen ('Rex Allen'), a U. S. government veterinarian, rides into the picturesque town of Pine Rock, near the Canadian border, to take the place of the regular vet who is on vacation. Used to doctoring animals in Texas, Allen finds out that herein the heart of the fox-farming industry, he is to doctor the most finicky and high-priced of fur on four feet. On the farm of Mel Richards (Tom London), Allen learns the habits of the valuable creatures from Richard's niece, Jane (Mary Ellen Kay, and her ten-year-old brother Danny (Jimmy Moss'), and on his own learns that the trusted owner of the trading post, Steve Baxter (Roy Barcroft) heads a gang that is smuggling counterfeit money across the American/Canadian border in the fox cages.

"RIDE!..REX...RIDE! - HIT THE TRAIL TO HIGH ADVENTURE!"