In this follow-up to the original family hit, Nanny McPhee (Emma Thompson) appears at the door of a harried young mother, Mrs. Isabel Green (Maggie Gyllenhaal), who is trying to run the family farm while her husband is away at war. But once she's arrived, Nanny McPhee discovers that Mrs. Green's children are fighting a war of their own against two spoiled city cousins who have just moved in. Relying on everything from a flying motorcycle to a tree-climbing piglet, Nanny McPhee uses her magic to teach her mischievous charges some new lessons.