You are an individual living in the world of Snow-piercer. The world has frozen over in efforts to reverse global warming and only one train remains that holds everything needed to be self-sustaining and has a track that spans the globe. (Food production, heat, energy, all supplied by the Eternal Engine). The ticket determines their amenities onboard (1st Class passenger, 2nd Class passenger, 3rd Class, and various worker classes) and individuals were selected through a random lottery. However in the ensuing panic, hordes of people without a train ticket forcefully board the train despite the train’s guards. The non-ticket holders are stowed in the lowest carriages of the train and endure a life of great suffering. Non-ticket holders will endure all the world in perpetuity in the train and cannot step outside without dying. However their existence threatens the self-sustainability of the train. Tallies who show special skills as children or are academically gifted are tested and taken up train to enter into an apprenticeship.
There is an uprising of the non-ticket holders, namely, the Tallie Revolution, which attempts to overtake the train and establish an equal life inside the train where such divisions are removed. They have been successful in taking a portion of the train and the success and failure of the revolution are both equally possible.