The series takes place in a post-apocalyptic world where an experiment to stop global warming has gone wrong, causing an ice age that has frozen the entire planet. The only survivors live on a massive train called Snowpiercer, which travels around the frozen world. The train is divided into two main sections: the luxurious and spacious cars at the front, where the wealthy and powerful live, and the cramped and dirty cars at the back, where the poor and marginalized live.