Melanie dreams of a child gutting a rabbit while sleeping in Big Alice's brig.
Alex comes in with her snow sample and tells her it contains water and dirt. Melanie asks if there was ammonium sulfate. Mel tells Alex it was snowing but she doesn't believe it.
Till picks Layton up for work. He warns Zarah to stay out of Third but she insists she'll be fine.
As they walk, Till fills Layton in on the situation on the train, including an assault near the tea room that resulted in a Tailie woman getting maimed.
When Layton asks her to investigate, she points out that she has no authority on the train. Layton takes her to Roche and they make her Train Detective.
Layton and Roche interrogate Kevin and get information about Big Alice by offering him real food. He lets them know that Icy Bob has been augmented for cold resistance and that there's a hundred crew aboard.
Alex and Wilford meet with Melanie and threaten to turn the power off.
A communique is delivered and Ruth rushes it to Layton. Wilford proposes a prisoner swap where they can meet.
As the prisoners cross over, Alex rushes up with the vial of snow sample. When Melanie asks her to come back to Snowpiercer with her, Alex smashes it on the ground.
Layton and Melanie consult on Wilford's next move. Melanie heads to the engine.
Till goes to check on the assault victim and discovers it's Lights and her fingers have been cut off.
Melanie tells Javi and Ben about the snow. She hypothesizes that the CW-7 is falling out of the atmosphere.
Kevin comes to give Wilford his report and Wilford pours him a bath as a reward. Wilford sends Alex away when Kevin reveals that he ate food aboard Snowpiercer. Wilford gets into the tub with Kevin and hands him a razorblade with which to commit suicide.
Zarah brings supplies down train and discovers Josie is in the recovery room, a Jane Doe. She poisons Josie's IV and leaves but changes her mind and goes back to prevent the poison from killing her.
Till questions the pastor who runs the tea room, a multi-denominational shrine car. There is a shrine to Wilford.
Till sells his weed from Big Alice to Terence for encyclopedias.
Osweiller and LJ come to Terence looking for work.
Zarah looks for Audrey in the Night Car. She's looking for advice and Audrey advises that she protect Andre at all costs because he's the train's only hope.
Javi sends a weather balloon into the atmosphere to measure the temperature up high and reports back to Layton that it's warmer.
Layton and Cavill discuss how to handle Wilford. Melanie recommends he get Ruth on his side. She sends a communique back to Wilford inviting him to a summit in the First Class dining car.
Wilford accepts and intends to attack Layton.
Ruth preps her team to host Wilford.
Till reports to Layton and Roche about Lights' assault. She suspects Wilford supporters of trying to stir up trouble.
WIlford and Alex discuss the plan to kill Layton. She secretes a razor blade in her mouth.
Zarah visits Josie.
As Wilford makes his way through Third, LJ approaches him and hugs him, telling him he still has friends.
Wilford is applauded as he enters the dining car.
Melanie announces their discovery and lays out the plan to collect data to find a warming spot on the globe where they can recolonize.
Wilford disputes the findings and calls Melanie and Layton untrustworthy. However, the Drs. Headwood inform him that the theory holds. Wilford points out that the station needs to be manned and it'll have to be Melanie.
Melanie agrees if he agrees to cease all hostilities and provide her with the equipment she needs. As the crowd cheers, Alex starts to make her move but Wilford calls it off and she injures her hand with the razor blade.
Wilford salutes the train with a three finger gesture that makes a "W" shape for his name. Till realizes that Lights' injury has turned her hand into the same gesture.
Zarah comes to Layton and tells him about Josie. He rushes to her bedside. She opens his eyes for him.
Before returning to Big Alice, Alex confronts Melanie and leaves a bloody handprint on the bulkhead.