Cullen awaits the birth of his baby, laboring under The Swede's thumb at Fort Smith. Durant deals with the fallout from a railroad accident.

As Cullen plans an exit from Fort Smith, he challenges The Swede; when a new adversary arrives, Cheyenne feels his presence.

Cullen goes back to work on the railroad and butts heads with his new boss. Durant and Campbell battle over a valuable piece of real estate.

Cullen deals with trouble at home as he takes railroad matters into his own hands. Campbell makes a move against Durant and Mickey.

Cullens's family is at risk when a stranger arrives, stirring up old feelings; The Swede faces the consequences.

Following an attack by a bear, Elam struggles to survive in a Comanche village and find his way back to Cheyenne.

Cullen makes a decision to ensure his family's safety. Campbell hires a new federal marshal to clean up the streets.

Cullen goes head to head with the new marshal to recover his arrested railroad workers. Campbell confronts Louise over a story.

Cullen, Durant, and Campbell try to negotiate a settlement on how the streets will be policed. An act of terror strikes Cheyenne.

Cullen and Durant fight to save the life of a criminal. Meanwhile, Louise tries to provide support as Ruth copes with a great loss.

Cullen grapples with Ruth's unexpected decision; Louise jeopardizes her reputation to fight for a story she believes in.

As the railroad prepares to leave Cheyenne behind in the Season 4 finale, Cullen returns to Fort Smith to retrieve his family.