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

Cullen and Fong find themselves in peril as they transport a locomotive over the Sierra Nevada mountains. The Swede gains Phineas' trust.

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.

Unexpected violence erupts in Chinatown during the festival of Tin Hau Don; Cullen confronts the Swede; and Durant involves Maggie in his latest scheme.