Joseph Black Moon and Reverend Nathaniel Cole travel into Cheyenne territory in hopes of a peace talk. Lily Bell and Thomas Durant discuss the future of the railroad construction. Cullen Bohannon and Elam settle their differences in a public fight.
Durant and Lily travel to Chicago - he, to further discuss the railroad with Senator Crane; she, to meet with her deceased husband's family. The Irishmen from Hell On Wheels prepare to hang Elam. Cullen interferes and helps him escape.
A train is derailed by the Cheyenne. Durant orders Cullen to lead a team to track them. Lily moves out of Durant's coach and into her own tent beside the brothel. Tension mounts for Cullen's team in the pursuit of the renegade Indian tribe.
Cullen and the search party find the natives who attacked the surveyor's camp and later derailed a train; Elam and Eva discuss their future, before getting a strange visitor; and the railroad crew reaches the important 40-mile mark.
Durant and Lily conspire to gain investors' interests. Sean and Mickey McGinnes exact their own revenge on The Swede. Elam and Eva each begin to see the future differently. Cullen tracks down the elusive Sergeant Harper.