While Theodore Roosevelt and his men help catch a horse thief, the town of Medora is thrown into turmoil when its enigmatic founder, the Marquis de Morés, is unexpectedly arrested and taken to Bismarck to stand trial for the murder of a rancher.

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.