Nanny McPhee: a name that strikes fear in the hearts of naughty children.

A larky sequel to the 2005 surprise hit, Nanny McPhee Returns stars Emma Thompson (who also wrote the screenplay), reprising her role as the warty caregiver and domestic enforcer. She speaks softly and carries a very big stick, an alpenstock with wandlike magical powers that instills virtue in her wards.

Featuring pigs that fly (and synchronize-swim), an unusually graceful elephant, and a crow that is Nanny's sidekick, the film boasts animal magnetism for kids and emotional resonance for adults.

Like Toy Story 3 and The Kids Are All Right, Nanny M is about one who helps to build the character of children and when done, bids them goodbye. "When you need me and do not want me, I will come," Nanny announces to her charges. "And when you want me and do not need me, I will leave." (Thompson conceived Nanny as the Shane of the nursery.)

The first installment of Nanny M was set in Edwardian England. This time around, the mystical time-traveler materializes in rural England during World War II.

She comes to the aid of beleaguered mom Isabel Green (Maggie Gyllenhaal, with a perfect British accent). Isabel's husband is away at war, her three children are running riot, and her snooty niece and nephew have been dispatched to the farm that her brother-in-law (Rhys Ifans) wants to sell to pay his gambling debts.

At its best, Nanny McPhee Returns has the playful surrealism of Babe, if Babe had been directed by Terry Gilliam. (Maybe it's the combination of peripatetic piglets and Thompson's off-center humor.)

It's actually directed by Susanna White, a British television director (Bleak House) who strikes a nice balance between slapstick and earned sentimentality. The movie warms the heart without using schmaltz to fuel its fire.

From grown-ups to rug rats, the actors are a joy, especially Maggie Smith as a fuddled shopkeeper who would seem to have lost her last marble. (Even those immune to bathroom humor have to chortle at the woman who mistook a cow pie for a cushion.)

The screenplay's nicest visual touch is that people mirror their context. When the children are brutish and nasty, Nanny M is unibrowed and very unattractive. But as the charges master Nanny's lessons in self-control and empathy, snaggleteeth and warts are replaced by an even bite and clear skin.

An eloquent way to illustrate how internal change can improve external looks.

Nanny McPhee Returns *** (out of four stars)

Directed by Susanna White. With Emma Thompson, Maggie Gyllenhaal, Maggie Smith, and Rhys Ifans. Distributed by Universal Pictures.

Running time: 1 hour, 45 mins.

Parent's guide: PG (wartime themes)

Playing at: area theaters