Convinced that Theodore Roosevelt is responsible for his arrest on murder charges, the Marquis de Morés challenges Roosevelt to a duel. While the Marquis sits in jail, his rivals in Chicago dynamite one of his refrigerated train cars.

Theodore Roosevelt travels to Bismarck to attend the murder trial of his old rival, the Marquis de Morés. Back in the Badlands, the Marquis' wife, Medora, is visited by her father, who tries to convince her to leave her murderous husband.

When Theodore Roosevelt assists a Sioux brave in finding his stolen horses, they help identify a notorious horse thief. Though found innocent of murder, the Marquis de Morés must still repair his damaged reputation with his father-in-law.