How did the gnomish Rev. Walter Goodfellow (Rowan Atkinson) end up with an effortlessly sensuous woman like Gloria (Kristen Scott Thomas)? Gloria’s wondering the same thing as of late, since the torporous serenity of her sexless marriage is perpetually disturbed by the automotive escapades of her shag-happy daughter Holly (Tamsin Egerton) and a neighbor’s yappy Jack Russell. No wonder she’s settling for the yee-haw attention of leather-faced golf teacher Lance (Patrick Swayze). But in breezes new housekeeper Grace Hawkins (Maggie Smith) in her heather-colored coat and, like magic, the barking stops overnight. The best moments of Keeping Mum, a pitch-smeared variation on the Mary Poppins tale (children may want songs and treats but adults just want an assassin), bleed into that uniquely British knack for gleeful, magical viciousness. While the world doesn’t need one more scene revolving around an overheard conversation that leads to a tremendous misunderstanding, the story nuances about Gloria’s teetering fidelity and Grace’s unwavering loyalty to her new family—not coincidentally bolstered by the very talented female leads—moves the proceedings safely away from cartoonish. Sitcomish, maybe, but British sitcomish, with its classier pedigree and a looser hand with the dark stuff. And then there’s Scott Thomas. Her daughter may parade around topless, but what lasts is the smoldering memory of a still-dressed Gloria meeting her lover’s eyes and peeling down one shoulder of her navy button-down cardigan. Yowch.