A band of masked robbers hijacks Durant's payroll train. As they make off with the payroll money, a guard shoots one of the bandits in the shoulder. The wounded bandit takes off his mask as he flees: It's Cullen.
The payroll train arrives at Hell on Wheels and a mob of railroad workers attacks the guard after the foreman sighs, "Not again."
At the railway office, Lily tells Durant that railroad construction has been slow and complains about the foreman, Mr. Schmidt. Elam informs Durant that the payroll train was robbed again.
Hawkins, ringleader of the robbers, hands Cullen his cut of the plunder. Cullen urges him to save their money for the start-up Confederate colony in Mexico, but Hawkins insists the men "deserve a chance to whoop it up" after their victory. Doc, an old friend of Cullen's, extracts a bullet fragment from Cullen's shoulder and apologizes for involving him in the gang.
At Hell on Wheels, Ruth approaches Sean, who's hawking plots of railroad land with Mickey. Ruth sweetly explains that she can't pay the church's rent, since her father's hiatus from preaching has resulted in a loss of collection money. Sean suggests they discuss it over dinner. She coyly declines but promises to have the rent soon.
Durant runs into The Swede, who's tending to his muckwagon. The Swede offers to help restore order in town, but Durant advises him to embrace his new job.
The train robbers drink at a shack, where a pair of former Union soldiers provoke Cullen with comments about Southerners. Cullen pummels them bloody, then rinses his hands while Doc encourages him to let go of the past.
Elam takes the train to Durant, Nebraska, where he pays a visit to Eva at her new home. "I guess you got what you wanted," she says when he confirms he's working for Durant. Mr. Toole joins them and says Durant appointed him the town's station agent. He puts his arm around Eva, prompting Elam to leave.
At Hell on Wheels, Nell finds one of the whores murdered in bed. A crowd watches silently as The Swede loads the body onto his wagon, but Sean whispers to Mickey that "this could be our opportunity."
Spying on another train, Cullen recognizes Elam as the guard then demands to be the first man on the train. "I think I've earned the right to take him down," Cullen says.
Durant informs Lily about the murdered woman, a first for Hell on Wheels. Lily insists they find and punish the killer but Durant says no one cares because she was a whore. Lily points out that he hangs horse thieves but Durant says horses are more valuable than whores.
As the bandits rob passengers on the train, Cullen barges into the payroll car and orders Elam to hand over the money — explaining that he's saving Elam's life. Elam refuses and Cullen urges the robbers off the train, saying Elam overpowered him.
The Swede enters Lily's room to change her chamber pot, acknowledging his demotion and Lily's rise to power. Lily gives The Swede money to ensure the dead whore receives a proper burial.
At his desk, Reverend Cole insists to Ruth that he's ready to preach again. She produces a bottle of liquor and moves to empty it on the ground, but he stops her for one last drink. She leaves him with the bottle.
Cullen urges the bandits to head straight to Mexico, but Hawkins insists they rob one more train and questions Cullen's motives. Cullen backs down and agrees to one more robbery.
Durant chastises Elam for letting Cullen live, but Elam points out he was merely hired to protect the payroll. He then offers to help get Hell on Wheels back on track. Durant hesitates, on account of Elam's race, but says he'll consider it.
At the brothel, Nell strikes a protection deal with Sean for of her profits. He later tells Mickey she agreed on the condition that they kill the whore's murderer. Mickey insists he's not a killer and storms off.
Doc urges Cullen to forgo the heist and leave, saying the others are unhappy with him.
Reverend Cole lies awake in bed, an empty liquor bottle at his side, as Joseph and Ruth make love in the next room.
The Swede feeds trash from his wagon into a bonfire. He finds Cullen's "Wanted" poster, crumples it up and throws it in the fire.
At the saloon, Elam turns down a prostitute's advances.
Lily approaches Durant's quarters in the dark of night. Bracing herself, she follows him in.
As Cullen's cohorts rob the train, Cullen points his gun at one who is terrorizing a mother and child. The bandit coldcocks Cullen.
Standing at the edge of a river, Lily tells Durant that the Sioux tribe considers the land on the other side sacred and Robert wanted to avoid it. Durant says the Sioux "will be the least of our troubles if we don't get this railroad under control."
Cullen sits in a prison wagon, where he hums and jokes with a fellow prisoner.
The Swede and Reverend Cole stand over the whore's grave. Cole is unable to pray so The Swede conducts a brief but scathing eulogy.
In town, Elam sees the Freedmen laughing around a fire but walks past them.
From his jail cell, Cullen watches a firing squad kill the other prisoner. Cullen sits back and closes his eyes.