 Sgt. Shane Rollins is assigned to mediate disputes between an advancing railroad track-laying crew and French Canadian trappers in Northwest Canada. Flood, the railroad boss, is ruthless, uncompromising, and sadistic in his methods and recklessly plans to blow up the trappers  lucky cave where their equipment is stored. In addition, he has callously abandoned pretty Indian maiden Nina after meeting beautiful Dawn MacDonald. When Nina commits suicide, Indian trapper Black Wolf vows vengeance and prevents Flood from dynamiting the cave. Although he and Flood kill each other, Rollins and Dawn, who were in the cave, are saved. After Rollins restores peace between the groups, he and Dawn are married.