When Ruben Beeler finds a rancher friend shot to death and mutilated, he calls on Marshals Marion Daniels and Homer Poteet for help. That call begins a chase that takes the men from St. Joe into Kansas and down to Hell on the Border and the Fort Smith court of Hangin' Judge Issac Parker. In pursuit of the killers, the marshals venture into the Oklahoma Territory, or "The Nations" as it was known at the time, following a path of bloodlust that began before the killing of Arkansas Bill Cole. Serial killers are nothing new, as the marshals find out on the Cutthroat Trail.