As an officer interrogates Cullen, flashbacks reveal that Hell on Wheels has been ransacked and burned to the ground. The officer is investigating the connection between the destruction and a letter about Durant's corruption that the Senate Committee on Railroads received from Lily. Cullen is silent except for a single whisper: "The White Spirit."
Before the destruction, the townspeople gawk as Durant tears through hospital tent in search of painkillers. He pries a bottle of Laudanum from a patient's hands but is stopped by Eva, who gives him opium pills from her purse. Once calmer, Durant confesses his fear that his addiction will be the ruin of the railroad.
At the railway office, Lily informs Cullen she's been demoted to freight clerk, and hurt that Cullen would reveal information to the Durants during their dinner with them, but not to her. Cullen cuts her off: "All I got right now is this job and you." He asks her to come watch him drive the train across the bridge the next day.
Hannah Durant thanks Eva for taking care of Durant and promises to see that Toole gets "a nice raise." Hannah suggests Durant return to the hospital in Chicago, but he insists on being present to explain the mileage situation to the board when they arrive. Hannah recommends offering Cullen a partnership if he will help handle the board.
At church, Ruth rebuffs Sean again: They can't marry because he's Catholic and she's a Congregationalist minister.
At his newly-finished home, Elam tells Psalms that Durant will let him keep the house if he agrees to kill someone. Psalms notes that Elam has killed before, but Elam says, "It was always somebody that needed killing. This is different."
That night, Toole confesses that he envies the way Lily looks at Cullen. Cullen, in turn, reveals he is increasingly enamored of Lily. At the sound of rustling in the darkness, Cullen says that Indians watch them every night, but he can't figure out why they don't attack.
In present-day, the officer asks why Cullen didn't send a scout to investigate the Indians. Cullen says scouts would have been killed and he couldn't spare any men.
Before the destruction, Hannah detains Lily on her way to the bridge crossing. Hannah hands Lily a ticket to New York and promises to write out a check and introduce her to a family in need of a governess.
Cullen starts the train as Durant and the crew wait anxiously on the far side of the bridge. He successfully crosses as the crew cheers.
Lily breaks into the railway office and steals Durant's ledger from the safe. Elam approaches as she leaves, and she tells him Durant is at the bridge. Elam watches her walk away.
Elam tells Eva about the riverside house, but she turns him down out of allegiance to Toole. "I got to pretend there ain't such a place."
At the bridge, Durant asks Cullen to help appease the board in exchange for partnership in the railroad and forgiveness of his debts. Cullen declines. "All my debts to you were buried with Doc Whitehead."
Hannah stands over Durant's shoulder as he grudgingly writes a check to Lily. He insists she won't leave the railroad, even for money. "I will do this my way if your way fails," he says.
Lily brings Cullen the ledger and proposes they take Durant down and build the railroad together. He implores her to burn the ledger before Durant kills her. "I guaran-damn-tee he's already thought about it."
A flame appears in the distance. Cullen shoots at the white figure holding the fire and it disappears. He investigates and finds a drop of blood on the bridge track.
The next day, Lily asks Elam to deliver a package for her if she is killed. He initially refuses, but relents when Lily acknowledges the home he built for Eva.
In town, Cullen asks Joseph what it means when an Indian paints himself white. Joseph says Cullen has seen the White Spirit, and it means the Sioux want everyone dead. Cullen asks Joseph to take him to the Sioux.
In the saloon, Sean tells Mickey he's converting for Ruth. Mickey explodes, saying Sean will burn in Hell. "I'll have to disown you," Mickey exclaims.
Psalms asks Eva to talk to Elam, who's heartbroken.
As they ride, Joseph tells Cullen that a blood moon is coming: "It's a time for bloodletting, the settling of scores." They peer over a hill and see a field filled with Sioux teepees.
In present-day Hell on Wheels, Cullen tells the officer that he telegraphed for reinforcements after his discovery, but the fort sent a meager five recruits and a small cannon.
Sean insists Ruth baptize him, but she points out he'll have to give up the saloon and whorehouse. He persists, asking, "Does your God allow you to deny me access to him?"
Elam finds Eva inside his house. "I'll always love you," she says, "but my future is with Mr. Toole." Outside, Toole calls for Eva. The two emerge and Toole aims his gun at Elam. Eva insists it's over with Elam but Toole says "God is a malicious bastard" and Eva's "heart is for this black son of a bitch." She pleads, "Don't!" But Toole puts the gun under his own chin and fires. Eva screams.