Fur trader Jules Moreaux is killed by raiders terrorizing the section patrolled by Canadian Mounties Sergeant Jim Cameron and his brother, Constable Bob Cameron, who find Jean Duncan hiding in a back room of the trading post. She says she is not sure she can identify the gang leader as Pierre Ledoux whom the Mounties suspect. Ledoux reaches Moosehead ahead of the Mounties and reports to Mart Duncan, Jean's uncle and secret leader of the fur raiders. LeDoux is ordered to backtrack and try to kill Jean in the event she recognized him, but misses. At the suggestion of RCMP Inspector Wylie, Jean goes to work for her uncle, sees Ledoux, but Jim is forced to release him for lack of evidence. Jim is suspended from the Mounties and his actions become suspicious to both the raiders and the Mounties, he attempts to loot Moreaux's cabin and is attacked by LeDoux, there for the same purpose. Jim hides the raider when his brother shows up. Duncan, about to flee town with the raider's money, is stopped by Ledoux, now friendly to Jim. The Mounties arrest Jim for apparently trying to rob Duncan, and he is drummed out of the service and jailed. Ledoux helps him break jail and takes him to the gang's hideout where Jean is a captive.