The Baker family, a happy family with 12 children, is now unable to escape the difficulties of time. With his eldest daughter Nora (Piper Perabo) getting married and pregnant, and his child Lorraine going to New York for further studies, Tom (Steve Martin), a parent, deeply feels that the time for family gatherings will be less and less, and this year's holiday may be the last opportunity for all to go out, so he and his wife Kate (Bonnie Hunt) carefully planned a cozy travel plan on Lake Winnet. However, what Tom never expected was that his old schoolmate enemy Jimmy (Eugene Levy) would also bring his eight children to Lake Winnet to spend the summer. Two competing dads and two noisy families meet together, and the lakes and mountains instantly turn into a battleground full of gunpowder. All 24 people from the two families, old and young, all mobilized to devote themselves to this battle for their respective "honors". In a family battle full of restlessness and laughter... This film is a sequel to the 2003 family comedy "A Basket of Children".