Though Marigold, Zinnia, and Lily Silver couldn't be more different, they're all excited about their various plans for summer vacation. Twelve-year-old Marigold is hoping to get her first kiss from her big crush, while Zinnia, eleven, will most likely spend her time in Marigold's shadow. And little five-year-old Lily, though angelic, has a knack for stirring up mischief wherever she goes. But any expectation of summer fun comes crashing down when the sisters' parents send them to Cape Cod to visit their aunt Sunny. Small-town life is not what these L.A. girls had in mind. They must adjust, however, to things like sharing a room and living without a TV. With the help of Aunt Sunny's zany disposition and yummy brownies, though, the girls are quickly won over, and before Marigold, Zinnie, and Lily know it, they're cracking lobster shells at clambakes, making new friends, and even organizing a local talent show.