Mr. Wilford arrives and threatens Snowpiercer, so Melanie makes a move that can't be undone.

An exchange is made between the two trains, but a far greater revelation might be just over the horizon.

Melanie embarks on her most dangerous mission yet, while Layton reckons with his personal choices.

As the Big Alice crew are granted shore leave on Snowpiercer, Layton and Wilford have differing opinions on the future.

Layton and Miss Audrey make a risky play for Big Alice, but Wilford has his own plans.

An engineering catastrophe on Snowpiercer forces Layton to make a difficult choice, one that might cost him everything.

Wilford presses forward on his endgame while those who are close with Layton grow anxious to learn their fates; Josie tests her newfound ability.

As the train approaches Melanie's retrieval point, Layton leads a furious attempt to try and pick her up but not without some sacrifices.

While Wilford emphasizes his rule aboard his icy train, Layton's pirate train continues its dangerous quest for warm spots, and comes across something entirely unexpected.

Layton goes on the hunt, as Wilford works to boost morale. The resistance discovers a threat that could undermine everything they've worked for.

Alex must finally deal with her parental figures as a track obstruction uncovers a painful past.

A series of terrorist attacks threatens to derail Layton and Zarah's big day.

Layton realises some dreams are out of reach. As the rest of the train deals with Layton’s status change, Wilford makes a staggering discovery.

As the train detours from New Eden, an environmental catastrophe threatens everyone onboard.

Reunited with old friends, the train throws a party. Alliances are tested as the truth is finally revealed.

It all comes to a head as old adversaries clash, with New Eden hanging in the balance.

The Snowpiercer crew marvel as a rocket shoots through the sky, crashing nearby. Melanie sends Till and Ben to investigate. Flash forward to nine months later, New Eden blooms.

Layton hears the deal: Liana for Big Alice. He agrees and the trains dock at the silo. While Layton, Ben, Till, Ruth, and Alex stew in a holding room, Josie is taken to Headwood. Milius introduces his partner in crime: Wilford.

Nima needs more samples for his experiments, so Milius sends Wilford and the soldiers to collect; privately, Milius tells Wolf to kill Wilford; Layton wakes up on an abandoned floor and is approached by humans with toxic gas scars.