After growing up as an orphan, Millie Longfellow is determined to become the best nanny the East Coast has ever seen. Unfortunately, her playfulness and enthusiasm aren't always well-received. Everett Mulberry has quite unexpectedly become guardian to three children that scare off every nanny he hires. About to depart for Newport, Rhode Island, for the summer, he's desperate for competent childcare. At wit's end with both Millie and Everett, the employment agency gives them one last chance --- with each other.