No one could accuse The Host's director Bong Joon-Ho of slacking when it comes to tracking down quality cast members for his English-language debut, Snow Piercer. His latest hire? Oscar nominee Octavia Spencer.

And with news of Spencer’s casting comes a few more details of what the sci-fi indie’s concept will be. Based on the 1970s French graphic novel Le Transperceneige, Snow Piercer is set in a future where the Earth has been devastated by a failed attempt to thwart global warming. A new Ice Age has killed off almost all life on the planet, and the only human survivors travel around the planet on the titular train, which is powered by a perpetual motion engine.

But life, as you might guess, is far from perfect in the various carriages, and a class system has evolved (though not necessarily the one you might expect, given that it’s a train). Soon there’s a revolt brewing…

Spencer is joining a cast that already includes Chris Evans, John Hurt and Tilda Swinton, alongside Korean actor Kang Ho Soong, one of the leads from The Host.

While Kelly Masterson wrote the latest draft, Bong has also worked on the script with producer Park Chan-Wook. The film will kick off shooting at the end of April. But before that, Spencer will report to the set of Diablo Cody’s still-untitled directorial debut, which starts production in March.