Lauren King (Diane Lane) is a highly "book-smart" and affluent 13-year-old American girl living in Paris with her mother (Sally Kellerman) and stepfather (Arthur Hill). 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 Château de Vaux-le-Vicomte, where Lauren's mother is becoming romantically interested in George, the sleazy director of a movie being filmed there, and where Daniel is taking a school trip, and they fall in love. 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. At Lauren's birthday party, Daniel punches George for making a crude suggestion about Lauren, and the two are forbidden to date by Lauren's mother.