The earth is dead. A sphere of ice, unmoving, shrouded in fog. A third of the population gone. With no power and wolves prowling the surrounding dead forests, the inhabitants of the small village of Milton are losing hope. But then a mysterious train arrives. A train with a one-way ticket for Flint. Why her? Where is it going? No-one knows. But she needs answers so she climbs aboard.


Taken to a secret location, she's placed with other talented teenagers from around the world and they begin their training. What for? They know they're being lied to, but discovering the truth is more dangerous than Flint can imagine.


They'll have to board another train. But this journey might just be their last.