In the revolution's aftermath, Layton struggles to govern the shell-shocked survivors. Melanie finally makes peace with her demons, only to realize the biggest threat to their survival is right over her shoulder.
The rebel forces are on the ropes when a dangerous foe defects to their side. They hatch a final plan to take control of Snowpiercer once and for all, but it comes at a grave moral cost, and just may destroy them all.
Revolution has finally come, and Layton leads the lower classes forward in armed rebellion. Melanie's house of cards collapses and she's in danger of becoming the first casualty in the battle for control of Snowpiercer.
Layton uses his new position as train detective to investigate the murder while gathering intel for the revolution on the side. Meanwhile, Melanie faces a resource crisis, with potentially drastic consequences for the entire train.
Snowpiercer, the Great Ark Train, has kept humanity from extinction for almost seven years. A rigid class system maintains order, with First Class holding power over workers, while a condemned Prison Class struggles to survive in the Tail. Now, a grisly murder is stoking class division, so Melanie Cavill, the powerful head of hospitality, deputizes a dangerous rebel to help solve the killing -- Andre Layton, the world's only surviving homicide detective.