Layton descends into the black market with Till, searching for both the killer and a valuable commodity for his revolution. Melanie stages a prize fight to distract the passengers from mounting class tension.

Tensions between Third Class and First Class are boiling as Melanie stages the trial of the Snowpiercer killer. Third Class threatens a work stoppage, demanding representation on the jury, and Melanie makes a fateful decision about which side to favor.

In the revolution's aftermath, Layton and Melanie realize the greatest threat to their survival is right over their shoulder.

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

Layton and Till investigate the murders. Wilford leads Miss Audrey down a dark path.

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

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.