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.

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

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

Melanie fights for survival in treacherous conditions, vying to do what others before her could not.

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.