A Mountie (John Preston) catches fur thieves with the help of his horse, Dynamite, and dog, Captain.

Inspector Dawson promises "Morton of the Mounted" a long-awaited vacation as soon as he solves the mystery of who killed an old fur trapper called Old Parker and a Mountie named McGee. Morton and his Mountie sidekick, Corporal Tiny Anderson, hit the tundra and Morton saves Mildred Boyd from a tormentor.