Nine months after Snowpiercer and Big Alice parted ways, Till and Ben encounter unforeseen enemies when Melanie sends them off the train on a reconnaissance mission. Meanwhile, the residents of…

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

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

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.