Snowpiercer, the great ark train, circles a frozen earth keeping humanity's last survivors until a murder onboard threatens the established order.
Layton investigates the murder while gathering intel for his revolution. Melanie faces a resource crisis that could impact everyone.
Layton descends into the black market, while Melanie stages a prize fight to defuse class tension.
A twist in the murder investigation brings Layton face to face with the murderer, and dangerously close to Melanie's secret.
Tension between Third Class and First Class comes to a head at the trial of the Snowpiercer killer.
Layton lays track for revolution while Melanie faces an engineering emergency that threatens every soul on Snowpiercer.
Melanie intensifies her search for Layton as he plots to weaponize her secret.
Revolution has finally come. As Layton leads the lower classes forward in armed rebellion, Melanie's house of cards collapses.
The rebel forces are on their heels when a dangerous foe joins them. A plan is hatched to take the train, but it may destroy them all.
In the revolution's aftermath, Layton and Melanie realize the greatest threat to their survival is right over their shoulder.
Mr. Wilford has arrived. As this new threat rattles Snowpiercer to its core, 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. Layton reckons with his personal choices.
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.
Melanie fights for survival in treacherous conditions, vying to do what others before her could not.
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.
Wilford presses forward on his endgame, as Layton sinks to new lows.
Hope is a powerful motivator. As things hit their darkest point, Layton hatches a plan.
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. Wilford works to boost morale. The resistance discovers a threat that could undermine everything they've worked for.
It's a game of cat and mouse as both Layton and Wilford vie for the upper hand.
Alex finally deals 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.
As the bomber is revealed, Layton comes to terms with his past decisions before making an irreversible call.
As the train grapples with Layton's status, he's discovering that some dreams aren't worth having. Wilford makes a shocking 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; nine months later, New Eden blooms.
Milius and his Animal Squad storm the train; Melanie realizes something is wrong and shuts the vault doors to the engine; when Ben's life is threatened, Melanie surrenders the engine.
Layton demands to use Big Alice to rescue Liana; Ruth, now mayor of New Eden, refuses because it's the town's power supply; Layton makes Javi jury-rig a solution, giving them three weeks of electricity.
Big Alice catches up to Snowpiercer and Milius radios them, inviting Layton over. Sensing a trap, Layton and Josie sneak onto Snowpiercer.
Layton hears the deal: Liana for Big Alice. While Layton and the others 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. Layton wakes up on an abandoned floor and is approached by humans with toxic gas scars.
Layton learns who was responsible for the experiments on Josie and Liana, and finds out who froze the world. Big Alice approaches New Eden but can't cross the booby-trapped bridge.
The bridge is safe to cross and Big Alice pulls into New Eden. Layton, Josie, and Liana sit stranded in the middle of nowhere, freezing to death, when a masked soldier appears. Alex finds herself in danger.
Alex sabotages the track switch computer and, with Layton's help, escapes to town hall. Till gets the drop on Ace and saves Layton and Alex from Rat. Melanie reveals the identity of Alex's biological father.
Nima heads for Snowpiercer. Layton and the Tailies fight their way uptrain when Ruth is captured. Nima tries to cut a deal and runs to the rocket control room to initiate the launch sequence.
