Time for a few more life lessons: The snaggletoothed British governess (Thompson), who appears when she's not wanted and leaves when she is, returns to help out the rural Green family. Mom (Gyllenhaal) is frazzled because Dad is off fighting WWII, their snooty city cousins---the Grays---are visiting to escape the blitz, and no-goodnik uncle Phil (Ifans) is trying to sell the farm. "The person who you need is Nanny McPhee!" shrieks the pottery in a confectioner's shop owned by the not-as-daffy-as-she-seems Mrs. Docherty (Smith). Just like that, this Mary Poppins with hairy moles, a stun-gun cane and a burping bird companion named Mr. Edelweiss materializes to work her magic.
You will believe that pigs can fly...and synchronize-swim in the style of Busby Berkeley. Thompson's imagination---she's also the screenwriter---knows no bounds, and she does a brilliant job of connecting the fantastical elements to the sobering realities of life during wartime. Even when it seems as if the story might lose its edge (a supposed death at the front is clearly a feint), Thompson counterbalances it with a no-less-troubling revelation; mortality isn't the only thing that can tear a family apart.
This is children's entertainment on the structural level of Roald Dahl and George Miller's great Babe: Pig in the City, even if the visuals rarely rise above polished and proficient. But Thompson and her terrific cast (a mix of seasoned British thespians and adorably talented youngsters) more than pick up the slack. They also elicit a few well-earned tears---this is one taskmaster babysitter you'll be sorry to see go.---Keith Uhlich
Watch the trailer