*Fresh from her SAG win for best supporting actress, “The Help’s” Octavia Spencer has joined the cast of “Snow Piercer,” the high-profile sci-fi indie project being directed by Bong Joon-Ho.

Chris Evans, John Hurt and Tilda Swinton are have already been cast, along with Korean actor Kang Ho Song, who starred in Joon-Ho’s international breakthrough, the Korean monster movie “The Host.”

“Snow Piercer,” which Joon-Ho co-scripted, is set in a future where, after a failed experiment to stop global warming, an Ice Age kills off all life on the planet except for the inhabitants of the Snow Piercer, a train that travels around the globe and is powered by a sacred perpetual-motion engine. A class system evolves on the train but a revolution brews.

Spencer plays a passenger on the train who joins the revolt in order to save her son.

Spencer is riding an awards season wave of acclaim for her work in “The Help.” So far she’s won a Broadcast Film Critics Award, a Golden Globe and a SAG Award for her portrayal of maid Minny Jackson in the adaptation of the Kathryn Stockett novel. She’s considered the favorite to win the Oscar.

Spencer next shoots Mandate’s untitled Diablo Cody project, which begins production in March, then moves to Snow Piercer at the end of April.