Elam strikes a deal with the McGinnes brothers, then quits the railroad. The Swede discovers Durant's fraudulent mileage. Cullen and Lily have sex.
Durant's wife arrives. Cullen reveals his aristocratic past to the Durants. Cullen blames The Swede for sabotaging the bridge.
Rev. Cole hijacks Durant's train to chicago. When Cole calls for his children, Joseph kills him. Doc is captured and asks Cullen to execute him.
Rebels attack Hell on Wheels, killing Nell and injuring Durant. Cullen fetches Doc Whitehead, who stabilizes Durant and saves his life.
Indians burn down Durant, NE. Durant saves Cullen's life to bring him back to Hell on Wheels and restore order. Elam kills Schmidt.
Eva reveals she's carrying Elam's baby. Workers strike after a Sioux incident. The crew fight off replacements and agree to work again.
Sean and Mickey take credit for Schmidt's murder. Lily confesses and the brothers are freed. They kill the German butcher and feed him to the pigs.
Cullen robs Durant's payroll train with bandits. Durant assigns Elam to security duty. The town deals with a prostitute's murder.
Cullen is interrogated, recounting events that led to Hell on Wheels' destruction. Joseph shows Cullen the Sioux army. Toole commits suicide.
Lily convinces Elam not to kill her. The Swede returns, badly burned. Sioux attack, destroying the town. The Swede strangles Lily.