An escaped criminal pretends to be a member of the Royal Canadian Mounted Police in order to prove his innocence of murder. Star Dennis Morgan plays two roles.

Northwest Mounted Policemen Fitzgerald and Herrick, who are later joined by Indian guide Uncas, have been detailed to track down a gang of whiskey-runners.

Rousing tales of the North-West Mounted Police are brought to life through photos and artists' sketches. In 1873, the North-West Mounted Police were established to maintain law and order in the North-West Territories. They undertook a trek from Fort Dufferin, south of Winnipeg, to Fort Whoop-up, near present-day Lethbridge, Alberta. The force raised the flag and proclaimed the Queen's Law, ensuring that the Canadian West would not become a lawless, American-style frontier.