When Elio Perlman’s curious, affectionate three-year-old little sister becomes an unexpected part of one unforgettable Italian summer, she charms everyone she meets—including Oliver. As Elio navigates first love, jealousy, and growing up, his tiny shadow innocently brings the two closer together, creating quiet moments of laughter, tenderness, and family that neither of them will ever forget. Through a child’s eyes, one summer changes all of their lives forever.