In the summer of 1980, 16-year-old Kaia Matheson travels from her home in Berkeley to a small island off of Cape Cod for a family vacation. Kaia hopes to confront her mother Jean about abandoning her in California, allegedly to pursue a high-powered career in Manhattan. However, Jean remains aloof and offers no apology for leaving Kaia in the custody of her controlling, alcoholic father. Intrigued by her rugged and intelligent older cousin Mark Karadonis, Kaia turns to him for companionship. Despite his misgivings, Mark is irresistibly attracted to his young cousin. When he arrives in Berkeley in the fall to start law school, the two