Widowed father Mr. Brown (
Colin Firth) is at his wits' end as NANNY MCPHEE begins, as his seven kids have just run off their 17th nanny. Just in time, warty, snaggle-toothed, bulbous-nosed Nanny McPhee (
Emma Thompson) arrives on a dark night and promises to set the household aright. She expects the children, especially chief schemer Simon (
Thomas Sangster), to live up to her expectations: They can be kids -- rambunctious, energetic, and silly -- but they must also respect others, including adults. Or, at least, those adults who don't appear foolish outright, like garish local widow Selma Quickly (Celia Imrie). When Mr. Brown's Great Aunt Adelaide (
Angela Lansbury) insists that he marry by the end of the month or lose her monthly checks, the children plot to chase off the widow, not thinking through the long-term effects. Nanny McPhee lets them and their father learn lessons the hard way, allowing Mr. Brown to figure out how he feels about his pretty housemaid, Evangeline (Kelly Macdonald), on his own.