Lauren King (Diane Lane) is a highly "book-smart" and affluent 13-year-old American girl living in Paris with her mother (Sally Kellerman), who works in the movie business, and stepfather (Arthur Hill (actor)). Daniel Michon (Thelonious Bernard) is a "street-smart" 13-year-old French boy who also lives in Paris with his father, a taxi driver. The two meet in the Vaux-le-Vicomte, where a movie Lauren's mother is working on is being filmed and where Daniel is taking a school trip, and fall in love. Lauren's mother fiercely objects to the romance. Daniel punches George, a sleazy friend of Lauren's mother, at Lauren's birthday party for making a crude innuendo about Lauren, and the two are forbidden to date. Lauren and Daniel soon meet Julius Santorin (Laurence Olivier), a quirky but kind elderly man, literally by accident. Daniel is unimpressed by him, but he fascinates Lauren with stories of his life, telling of a tradition that if a couple kiss in a gondola beneath the Bridge of Sighs in Venice at sunset while the church bells toll, they will be in love forever.