"Sister," the dazzling Swiss contender for the Best Foreign Language Film Oscar, is a story about a boy who deals with serious subjects in an adult way. Twelve-year-old Simon (Kacey Mottet Klein) commutes to work daily from the drab flat he shares with his twentyish sexpot sister, Louise (Lea Seydoux, a hot mess in too-tight jeans and blown-out hair). A cable car lifts him to a posh alpine ski resort where, like Jack atop the beanstalk, he helps himself to treasure. He filches expensive equipment, selling it down below to pay for rent, milk and pasta.

It's not a bad form of stealing, he reasons. The swells don't interrupt their vacations to report the thefts, they simply buy new gear. Simon's a survivor, the provider in the household, a bright boy who has taken a wrong turn because there's no reliable adult to guide him. The kids' parents, we hear, were killed in a car crash. Simon and Louise feast on stolen sandwiches, or engage in love-hate wrestling matches, and it's a rush of pleasure, a respite from the boy's worries that his neglectful sister probably will vanish soon.

When he reaches out to a wealthy, maternal English tourist (Gillian Anderson), hoping to form an attachment with her family, he threatens his own con. Heartbreakingly, he tries to buy his way into her good graces, because that's the only emotional currency he understands.

French-born director and co-screenwriter Ursula Meier balances the scenario's bleak, wrenching aspects with a stirring confidence in the redemptive power of love.

Meier also has a keen knack for film storytelling. She and ace cinematographer Agnes Godard use the mountain's elevation as a dramatic device and a vehicle for social commentary. It looms over the kids' apartment tower like an indifferent giant turning its back on the lower classes.

The fast downhill slide of the vacationers says something about Simon's moral trajectory, and a moment when he's trapped while pilfering supplies in a hotel pantry implies the prison cell that could be awaiting him. None of the ideas are forced. All are realistic, adroit and, like the naturalistic, un-self-conscious performances, hard to forget.

"Sister" will be cherished by fans of Francois Truffaut's French New Wave landmark "The 400 Blows" and the Dardennes brothers' great movies, particularly last year's "The Kid With a Bike." It's sometimes grim but never less than compelling.

Colin Covert • 612-673-7186