The hourlong drama pilot, directed by Doctor Strange helmer Scott Derrickson, is set seven years after the world has become a frozen wasteland, and the remnants of humanity inhabit a gigantic, perpetually moving train that circles the globe. It explores class warfare, social injustice and the politics of survival.

Sumner will play Bess Till. Thoughtful, empathetic and savvy, Bess is a brakeman, part of the train’s security force. She finds herself at the center of a mystery that rocks the train’s uneasy status quo. Connelly plays Melanie Cavill, a First Class passenger who works as the Voice of the Train; Diggs plays Layton Well, a prisoner who becomes a reluctant participant in a struggle that could upend life on the train.

Snowpiercer, a co-production between Marty Adelstein/ITV Studios’ Tomorrow Studios, Turner’s Studio T and CJ Entertainment, is executive-produced by writer-showrunner Josh Friedman; director Derrickson; Tomorrow Studios’ Adelstein and Becky Clements; and the original film’s Bong Joon Ho, Park Chan-wook, Lee Tae-hun and Dooho Choi.

Sumner, probably best known for her role in Noah Baumbach’s film Frances Ha, will next be seen in the upcoming Dayton-Faris Fox Searchlight film Battle of The Sexes, Doug Liman’s American Made, and the British horror film Caught. In TV, Sumner had recurring roles on AMC’s series Low Winter Sun, and on Showtime’s series The Borgias. She is repped by UTA, Sue Leibman/Barking Dog Entertainment, and Peikoff-Mahan Law Offices.

Snowpiercer is one of three TNT projects being produced by Tomorrow Studios, the other two being series Good Behavior and the Highland pilot.