In a harsh, uncompromisingly cold future where Earth has succumbed to treacherously low temperatures, the last remaining members of humanity travel on a train while the outside world remains encased in ice.

The surviving community are not without a social hierarchy. Those that travel at the front of the train live in relative luxury whilst those unfortunate enough to be at the rear remain clustered like cattle in claustrophobic darkness. Yet, things are about to change aboard the train as passengers become disgruntled...