In the sci-fi thriller “Snowpiercer,” class warfare goes express.

This movie, due June 27, imagines a future in which the effort to curb global warming results in a new ice age that makes the planet uninhabitable. The last members of the human race live on a train with a perpetual-motion engine, traveling on a track that circumnavigates the globe. As on a train today, passengers are assigned seats by class; only here, the classes are economic as well, with the poorest, lowest class consigned to the squalid tail of the train and the wealthy riders living in the opulent front cars. But the masses, led by the star Chris Evans, stage a revolt (the villains include Tilda Swinton) and try to shift the balance of power.

“Snowpiercer” is the English-language debut of the South Korean director Bong Joon-ho (“The Host,” “Mother”), who based the film on the French graphic novel “Le Transperceneige.” A fan of comics, Mr. Bong found the graphic novel in a shop in Seoul in 2005.

“I was fortunate, because at the time, outside of France, Korea was the only country where they published this particular graphic novel,” he said, speaking by phone from his home in Seoul. “I was taken by the unique setting and the artwork.”

The film draws stark visual contrasts between the classes. While many of Mr. Bong’s ideas were modeled on the graphic novel, his film forges ahead on its own through bold design choices.