"The Penderwicks at Point Mouette" is the third book in the Penderwicks series by Jeanne Birdsall. The story follows the four Penderwick sisters—Rosalind, Skye, Jane, and Batty—as they embark on a summer vacation at a beach cottage in Maine. During their stay, the sisters encounter new friends and face various challenges, including the complexities of growing up and the importance of family bonds. The narrative highlights themes of adventure, friendship, and the joys of childhood, all set against the beautiful backdrop of Point Mouette.