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

Cullen's search for the sergeant nears its end; Durant keeps to his hidden agenda while assisting in Lily's recuperation.

When Lily goes missing, Durant organizes a search party. A subsidiary request prevents Cullen from his continued search for the sergeant involved in the murder of his wife.

A bare-knuckle brouhaha between Elam and Cullen is spurred by Durant's latest attempt to deal with the railroad's financial crisis.

Durant challenges the Cheyenne to a competition in an effort to bring a halt to ongoing negotiations. Meanwhile, Elam and Cullen try to prevent bloodshed in town.

A former confederate soldier journeys to the transcontinental railroad to seek vengeance.

Cullen helps Elam track down a dangerous criminal; the town prepares to move down the tracks.

Cullen and Mei escort precious cargo through the California wilderness; Eva nurses Louise back to health.

Lily encounters natives in the wilderness. Cullen is questioned in regards to his recent actions against others. Meanwhile, Durant continues his push for political gain through his persuasions.

When a cholera epidemic hits Hell on Wheels, Cullen must find fresh water before his workers die. Durant faces political fallout.

After his workers defect to the Mormons, Cullen recruits Durant to help get them back. Meanwhile, Sean and Mickey's past comes back to haunt them.

Cullen is in California with the Central Pacific Railroad, and must deal with the new workers.

Cullen contends with violence in Chinatown set off by disgruntled railroad workers. Meanwhile, the Swede manipulates Phineas in his plot against the Mormons.

Cullen solves a Chinese labor strike in the wake of violence. Meanwhile, Durant pulls Mickey deeper into Union Pacific business.

In the aftermath of tragedy, Lily and Cullen struggle to maintain order in Hell on Wheels. Meanwhile, Elam makes plans for the future.

Cullen and Elam try to secure a new lumber source following a railroad accident; Durant tells Louise a secret about Cullen.

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.

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

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

Cullen faces life-changing decisions in Utah as Truckee adapts to life without him.

Cullen's nitroglycerin experiment provides an explosive backdrop for the railroad life in Truckee. Durant's plan turns deadly.

Durant dispatches Cullen and Elam on a mission of vengeance. Lily struggles to find her place.

In the Season 2 premiere, Durant and Lily steer the railroad further west, while Cullen and Elam land on opposite sides of the law.

Durant confronts a formidable threat to the rolling city, while a horrific crime leads Lily and Elam to join forces in order to attain justice.

A tragedy leads Cullen to defuse an internal threat to the railroad.