A film often smartly attuned to language, Beatriz at Dinner — a sober comedy about class clash and soft-to-hard racism directed by Miguel Arteta and written by Mike White — operates in several different idioms. English and Spanish (sometimes unsubtitled) are spoken, as are the lexicons of healing and affluence specific to Southern California, here just as often dissonant with each other as they are consonant.

The first 10 or so minutes of this fleet, dialogue- and dialectic-heavy film, though, are mostly wordless, tracing the routine of Beatriz (Salma Hayek), a self-described health therapist who works primarily in a cancer center, tending to the ill through massage. Beatriz also has private clients, including Kathy (Connie Britton), a Newport Beach matron who has requested an at-home rubdown before a dinner party she and her husband (David Warshofsky) are hosting. After the session, the healer's car won't start, and Kathy insists she join their six-person supper.

"She's not a housekeeper or anything — she's a friend of the family," Kathy pleads to Grant, who is reluctant to let khaki-clad Beatriz sit at the table with their soigné associates. That's one of several blistering lines that efficiently reveal appalling caste system and presumptions of intimacy. As other white moneyed couples arrive — played by Jay Duplass, Chloë Sevigny, John Lithgow and Amy Landecker — Beatriz finds herself either patronizingly listened to by the wives or insulted by the husbands.

Beatriz has good comebacks, recalling her protest work against land developers in her native Mexico. But she is not a saint; she can be fatiguingly sanctimonious, her wearisome traits finely calibrated by Hayek. Yet these nuances begin to harden into the manichean in the final act.