Jackson Tait, a railroad surveyor, and Peter Chow, his adopted Chinese son, arrive and announce that a railroad will run through Colorado Springs or Soda Springs. Meanwhile, Matthew discovers he's not included in blueprint plans for Sully and Mike's new homesite. When Sully finds out the railroad may be routed through Colorado Springs, he wants to move the family, but Mike doesn't. At the town meeting, Mike casts the deciding vote for the railroad, and Sully's angry. But when Dog Soldiers launch a scare attack upon railroad dignitaries and Mike refuses to join the townsfolk in embroidering Colorado Spring's virtues to the visiting dignitaries, it seems the railroad may not come after all. Meanwhile, Colleen's embarrassed when she stumbles upon Peter Chow bathing naked, but gets over it when she treats him for malaria. Sully tries to give his old homestead to Matthew, and comforts him when Matthew confesses that he feels left out. Against Sully's wishes, Mike influences Jackson Tait that the railroad would be good for the town, and he decides it will go through Colorado Springs. At home, Sully and Mike argue, and Brian, blaming the impending railroad for the strife, crashes his beloved train set. Mike and Sully comfort Brian and Colleen and assure them they're still getting married. Alone, they reaffirm their love, with Mike telling Sully the reason the train was so important to her was because it was where Sully first told her he loved her. When he assures her he still does, she promises that if she ever sees his heart breaking, she'll agree to leave. Paralleling Sully's hammering in the first nails to their new homestead, Mike drives the first spike for the railroad at the christening ceremony.