Ep 1. The Elusive Eden

As the fourth season of Hell on Wheels kicks off with "The Elusive Eden," Cullen Bohannon (Anson Mount) has all but disappeared from the Union Pacific Railroad's construction site after his wife's brutal murder by the hands of a Cheyenne Indian in the closing moments of season three. But after spending the winter surviving on his own and living off the land, Cullen makes his return to the camp to the surprise of many. Though he is struggling to come to grips with the loss of his wife, he is willing to plunge back into the fray.

Cullen's return coincides with the arrival of a new group of Chinese immigrants who are brought to Hell on Wheels to work on the project. Fleeing persecution, these immigrants have come to America in search of a better life and the promise of opportunity. However, they are met with hostility and racism from many of the workers on the railroad. The Chinese laborers are forced to live in subpar conditions, and they are not given basic necessities such as food and water. This results in a tragic incident that leaves Cullen wondering where he fits in the fight for equality.

Elsewhere, Thomas "Doc" Durant (Colm Meaney) is still scrambling to keep the project moving forward. Facing financial ruin and the threat of losing control of the railroad to his rivals, Durant is desperate to secure more funds to keep the project moving forward. He strikes a deal with the senator who he helped to get elected, but Durant's loyalties are called into question when the senator asks him to make a bit of a sacrifice for the greater good. The ensuing struggle puts Durant's relationship with the senator and the future of the railroad in jeopardy.

"The Elusive Eden" also sees the return of Swede (Christopher Heyerdahl), the former chief of security who was revealed to be working against Cullen and the railroad in the previous season. Swede has made his way to Mormon country, where he quickly establishes himself as an ally of Brigham Young and his followers. Swede's presence in this specific location suggests he is working on a potentially dangerous mission that could put the railroad's future in jeopardy.

Overall, "The Elusive Eden" is an emotional and suspense-filled episode that establishes the new conflicts and challenges that Hell on Wheels faces in its fourth season. It introduces new characters and storylines, while still delivering on the tension and drama that fans have come to expect from the series.