The movie is set in a post-apocalyptic world where an experiment to stop global warming has gone wrong, causing an ice age that has devastated the planet. The remaining survivors live on a train called the Snowpiercer, which circles the globe. The train is divided into two classes: the wealthy and privileged passengers in the front, and the poor and oppressed in the tail. The story follows a group of rebels, led by Curtis Everett (played by Chris Evans), who plan to overthrow the train's dictator, Minister Wilford (played by Ed Harris).