In a stylish summer camp, two twin girls, Annie and Hallie, meet by chance and, at first, could not be more different. Annie, a refined Londoner, has been raised by her mother in the public eye of high society, while Hallie, a carefree American girl, has enjoyed a laid-back life in Napa Valley with her father. After discovering that they are twins separated at birth by their parents' divorce, they decide to swap places without anyone knowing, with the intention of reuniting their family.
Annie heads to California to meet Hallie's unknown father, a charismatic vintner, and quickly realizes that her new life involves a love for outdoor adventures, not to mention the charming dog Hallie has left behind. Meanwhile, Hallie faces the formality of life in London and begins to understand her sister's world.
The twins must confront the challenges of their new realities and the need to face their parents, who have not overcome their differences. As the pieces of the puzzle come together, they begin to hatch a clever plan to reunite their parents, which includes a whirlwind of comedic and touching situations. The story weaves together love, laughter, and family lessons, creating a heartwarming tale about the importance of familial bonds that endure through time and distance.