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 looming railroad deadline throws Cullen and Lily together; Joseph and Elam deal with what their violent mission has wrought.

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.

Cullen fights to save Hell on Wheels.