Arianna, 19, hasn't experienced her first menstrual cycle yet, despite her breasts growing. Her prescribed hormones aren't helping. Her parents take her back to their lake house in Bolsena, where old memories resurface. As they prepare to leave, Arianna wants to stay behind to study, but her mother's discomfort is palpable. Alone, Arianna investigates her past and explores her body, including an encounter with her cousin Celeste, who has already lost her virginity. This pushes Arianna to confront her true sexuality.