The
story begins: "New York is a city where many people have unusual occupations".
Trying to keep Doc Savage out of your business by secretly watching him is dangerous work as the swindler Mahal finds out. Doc has Renny spy on the skulker. Renny learns that Mahal is an agent of a mysterious villain named Stroam. Stroam wants to prevent a mining engineer named Ben Lane from revealing his discovery. A discovery that will ruin Stroam and the interests he represents. The beautiful Canadian detective Midnat D'Avis, hired by Ben Lane informs Doc of Ben Lane's plea for help. High in the Canadian snow country Ben Lane and four men are mushing sled dogs south on their way to find Doc. Doc and his aides battle Stroam's gang of French-Canadian thugs and some ill-informed Mounted Police in their race to find Ben Lane and secure his discovery - a mountain of Benlanium!