Ask a scientist how to address climate change, and they might suggest phasing out fossil fuels. Filmmaker Alexander Payne (Election, Sideways) had a more creative, if implausible idea: shrink people down to five inches. They’d require fewer resources, but get to live like royals. That’s the conceit of Downsizing, which stars Matt Damon as a man who decides to live large by getting small. But it’s his co-star Hong Chau who steals the show. She plays a Vietnamese activist whose altruism stands in stark opposition to the conspicuous consumption of the miniature world.
Chau was born in Thailand to Vietnamese parents and raised in New Orleans. She planned on a career behind the camera until, after acting in friends’ films at Boston University, she found a knack for being in front of it. She got her first recurring TV role on the Big Easy–set Treme; her first film was Paul Thomas Anderson’s madcap 2014 neo-noir Inherent Vice.
To play Ngoc Lan Tran, Chau says she drew inspiration from “my parents, the community I grew up in New Orleans, Flannery O’Connor.” As Ngoc Lan’s left leg has been partially amputated, she says, “I basically was learning how to walk again.” But what appealed most was not her limp or her accent–acting skills she sees as “a bit of a party trick”–but the character’s rich inner life. In this case: a God-fearing straight shooter whose difficulties never distract from helping those who suffer even more.
Next up, Chau has a project with Beatriz at Dinner director Miguel Arteta, another class-conscious filmmaker. As she reflects on the enduring message of Downsizing, she sighs. Science might delay humanity’s downfall, she says. “But science can’t cure apathy.”
This appears in the November 27, 2017 issue of TIME.