Who: In this adaptation of a Noel Coward play, Jessica Biel plays Larita, the glamorous (and blonde) new wife of John (Ben Barnes), the handsome and empty-headed scion of an aristocratic family of twits and snobs in 1920s Britain. He brings her home to the dismay of his imperious mother (Kristin Scott Thomas) but the delight of his dad (Colin Firth), a witty outsider who suffers from his war experiences and is, in the words of the screenplay, “quietly sardonic.”

What: The movie begins as a drawing room comedy of the old fashioned sort, with mother turning up her nose at this newcomer (a suspected gold-digger, as well as a vulgar American), father welcoming her, and various other friends and neighbours revealing themselves as typical fox-hunting upper crust who spend their days playing tennis and being sporty. Soon, it turns more serious, a kind of drawing room melodrama with Larita fighting for her dignity in face of the insults and hauteur of an uncaring society. Meanwhile, a series of Noel Coward and Cole Porter tunes — Mad Dogs and Englishmen, for instance, or Let’s Misbehave — are sampled and the family Chihuahua is constantly on camera for reaction shots as the family and Larita clash.

Bottom line: As directed by Stephan Elliott (Priscilla, Queen of the Desert), this is a stodgy costume drama with a miscast Biel barely holding her own against a talented British cast — Firth and Scott Thomas are especially strong — and the clash of tones between wit and venom making an uncomfortable mix.

Key line: Father, at an uncomfortably quiet dinner: “Is it my imagination, or is the cutlery particularly deafening this evening?”

The verdict: A stuffy, not to say ossified, social comedy that’s worth watching mostly for the charms of Colin Firth and the performance of Scott Thomas of the mother-in-law from hell.