1883, Wyoming Territory. The death of Ida Sawbridge is mourned by her cousin George Gault. Learning that Ida died after drinking an elixir sold by a traveling theater troupe, Gault goes on a blood ride to track down the troupe and exact vengeance. Among Gault's posse is Alworth Nevins, a young Easterner who abandoned his Yale education to explore the West. Alworth has no interest in vengeance. Rather, he secretly hopes to protect a certain member of the troupe: Two Robes, a young Lakota Sioux woman. The paths of the various bands move toward a deadly convergence outside the town of Black Powder. There, a final reckoning will determine the fates of all involved.