After summer vacation begins, the Penderwick sisters separate as Rosalind, the eldest, heads off to New Jersey and the remaining three sisters, Skye, Jane, and Batty, depart for a memorable stay at Point Mouette in Maine with their Aunt Claire and therefore, the title of the book is The Penderwicks at Point Mouette. Being the next eldest Penderwick sister, an apprehensive Skye takes on the challenging task of being the OAP, or the oldest available Penderwick, at their new summer home. Cordial and unusual characters, such as Alec, a friendly man with musical talent, Dominic, a handsome and unkind boy, and Mercedes, a shy and sweet little girl, are introduced to the Penderwicks at Point Mouette and become a big part of their summer adventure. Due to their similar musical interests, Jeffrey, a close friend of the Penderwicks who travels to Maine with them, creates a special bond with Alec, and they start spending much of their time basking in the melodious drafts of piano music. Enthusiastically, Batty befriends Mercedes and the two of them have their own adventures throughout the story. Foolishly attracted to his looks, Jane falls desperately in love with Dominic and is therefore able to add a romance angle to her very own Sabrina Starr Series. Genuinely concerned about her sisters encountering trouble, Skye meanwhile takes her OAP responsibilities seriously and keeps an eye on her younger sisters. Humorous and heartfelt events that take place between the Penderwicks and their new friends, such as the memorable roasting of marshmallows near the beach, strengthen the newly created bond of friendship. Incautiously, Jane shares a quick kiss afterwards with Dominic and was ecstatic, but her heart breaks when he sends her a note saying “it didn’t mean anything.” Jane, heartbroken and irrevocably wounded, starts cutting off her hair in misery and was then taken to the barber’s shop and, in addition to her sisters, was given a new haircut. Kindheartedly, Skye slowly eases Jane out of her miserable and brokenhearted world and Jane is delighted to have created the plotline of her next novel from a real life experience. Liveliness and beautiful talent reveal themselves in Batty as she received music lessons from Alec and Jeffrey. Meanwhile, Jane starts making regular visits to the nearby golf course with Batty and Mercedes to go golf ball hunting. Noticing how many golf balls Batty and Mercedes had collected, Aunt Claire eventually suggests that they have a sale. Once they had set up for the sale, Skye, Jane, and Batty go to Alec’s house to see if he could loan them some water bottles. Pictures of Alec from his childhood years lay on the floor of his home and the Penderwicks couldn’t resist studying them. Quickly seeing the obvious resemblance between Alec’s childhood photograph and Jeffrey, the Penderwicks were surprised and a bit confused. Realizing that this might mean that Jeffrey may be Alec’s long lost son, the Penderwicks were joyful that Jeffrey might actually meet his father. Sincerely determined to find out the truth, Alec travels to Jeffrey’s home to talk to his mother, or his former wife, and to confirm the doubt of whether or not he is Jeffrey’s father. The Penderwick sisters, Aunt Claire, and Mercedes have an extremely difficult time of keeping their suspicions from Jeffrey while Alec is away. Unsurprisingly, Alec returns with the confirmation that Jeffrey is his son and informs Jeffrey of the shocking discovery. Vengeance on his father was what Jeffrey first desired since Jeffrey had to face thirteen years of abandonment and neglect from his mother and stepfather, and at that time, his father hadn’t been there for him. When Jeffrey finally forgave his newly-found father, affection and unity were restored in the small cottage of Point Mouette, and Skye was awfully thankful that she had succeeded in being the temporary OAP. Xylophones were one of the many musical instruments played at Batty’s farewell music concert in which everyone cherished the final moments of that exhilarating summer vacation. Yearning to see the rest of their family, the three Penderwick sisters wrapped up the memories of that summer and said their final farewells to their new friends. Zingy with excitement on being reunited, the Penderwick sisters returned home and were eager to retell their thrilling summer adventures.