ABANDON ALL HOPE: Hee-yeon Kim and Song-hee Kim.

It is an admitted prejudice of mine that movies starring small children—especially children who suffer in any way—are standing invitations for schmaltz. Korean-American director So Yong Kim’s semi-autobiographical Treeless Mountain has a premise especially ripe for mawkishness: Two sisters are dropped off by their fraught mother in the indifferent custody of an alcoholic aunt, whose attempt to be a caregiver lasts until she gets thirsty. Yet the movie is an exception to the sentimental rule, in no small part because the Korean actresses themselves are so resolutely dry-eyed. Their distress is etched across their faces, but they soon busy themselves roasting live grasshoppers as nibbles to sell for the money they believe will make their mom return. Six-year-old Hee-yeon Kim and 3-year-old Song-hee Kim (no relation to each other, or the director) are so stoic they make Star Trek’s Baby Spock look like a crybaby.

The movie does the emotional work for them. It is shot resolutely from their perspective—usually in close, and at their height—so that adults seem like live-action variations on Miss Othmar from Peanuts specials, except they’re usually saying something worse than a trombone’s “wah-wah” noise. (Our first hint that “Big Aunt” is a big drunk comes when the sisters, called Jin and Bin, start mornings with a routine of stacking empty bottles.) So Yong Kim is adept enough at evoking a pint-sized vantage point that in her linchpin scene, where the girls rush futilely after their departing parent, I found myself reliving a terror I had forgotten: It was how I felt when I was 6 years old, was separated from my mom in a crowded mall, and thought I had lost her and would never find her again. I thought I had forgotten that feeling. The movie hadn’t.

So Yong Kim’s debut feature, In Between Days, was set in Toronto and featured a far less sympathetic heroine, a teenage girl whose isolation was her own stubborn choice. But it shared with Treeless Mountain Kim’s gift for using quiet as a symbol for absence. In both movies she rejects musical cues, leaving the soundtrack dominated by the noises of wind and grinding bus engines. In Treeless Mountain, those buses are the transit lines that never bring the anticipated reunion, no matter how patiently the daughters wait. “But you had fun here, didn’t you?” Big Aunt cajoles as she prepares to jettison her charges, and it’s such a joke that you might cry. Somebody has to.