Marion, Homer, and Ruben are dispatched to Sioux Falls in the Dakota Territory to investigate the disappearance of another Federal Marshal, James Jacklin. While trying to gather information on Marshal Jacklin, the men come face to face with an entirely new situation that might be related...the kidnapping, selling, and forced prostitution of young Chinese girls. With the support of a determined and wealthy woman, the boys set out to find Marshal James Jacklin and to investigate a brutal market of slavery. Saddle up and join the marshals as they take to the Dakota Trail.