Nanny McPhee can tame even the most unruly children with a tap of her magic walking stick. Her latest challenge is the bratty brood of a recent widower Mr. Brown. He is under pressure to find a new wife or lose his much-needed allowance from wealthy Aunt Adelaide. His love for scullery maid Evangeline remains unspoken as he wincingly woos the eagerly merry widow Mrs. Quickly, but Brown's raucous rugrats have a plan to make things right, especially after they've come under the benevolent influence of Nanny McPhee, whose peculiar brand of discipline works wonders for everyone involved.