Arthur Wanamaker, a land baron based in Denver, is going home by train and when he arrives he is found dead. And a man who works in one of his mines is found with him. Jared Stone, the Marshall goes there and takes the man in. Everyone wants to hang the man but Stone wants to investigate. Stone is informed that because Wanamaker was killed while on a train, the railroad deems it as their concern so they send a Pinkerton Detective, Lattimer Finch to investigate. And he uses new methods to help find out what happened like finger printing and forensic medicine. Stone learns Wanamaker was a troubled man and there are other people who wanted him dead.