More than seven years after the world has become a frozen wasteland, the remnants of humanity inhabit a gigantic, perpetually-moving train that circles the globe as class warfare, social injustice and the politics of survival play out.
Alex sabotages the track switch computer and, with Layton's help, escapes to town hall; Till gets the drop on Ace and uses his sniper rifle to save Layton and Alex from Rat; Melanie reveals the identity of Alex's biological father.