The story takes place in a frozen world where an experiment gone wrong has plunged the Earth into an ice age. The remnants of humanity are forced to live on the Snowpiercer, a massive train that perpetually circles the globe. The train is divided into two main sections: the luxurious, opulent cars at the front, where the wealthy and powerful reside; and the cramped, squalid cars at the back, where the underclass struggle to survive.