Brule Conway and his dog Rinny are the best trapping team in the arctic territories of Canada. His rival, Pepite LaJoie, is jealous of Brule's trapping prowess and his success with the only woman at the trading post, Beth McVey. While Rinny guards Brule's furs, the conniving Pepite manages to distract the dog's attention and steals the pelts. Brule angrily turns his canine pal away for dereliction of duty, but Rinny is given a final test of honor - track down LaJoie and retrieve the furs.
Rin Tin Tin, Jr., the second in a long line of heirs to the canine acting dynasty, successfully took the Rin Tin Tin series into the era of sound films. He appeared in dozens of films and serials, as well as his own radio show. Future descendants would bring the legend to television in the 1950s as well as a more recent revival in the 1990s.