A billionaire auto magnate's virginal teenage daughter falls in love with an older, free-spirited drifter. Their romance is one that her parents vehemently want to prevent. Lisa (Ornella Muti) is very curious to explore her new-found feelings of desire, but her father forbids her to see Robert (Les Rannow). In their desperation to be together... alone... Lisa and Robert steal her father's boat and set sail to a deserted, isolated island. Here they are finally able to run uninhibitedly along the beaches and discover each other's physicality. Meanwhile, Lisa's parents and the police are searching for the young lovers who are living and loving a passionate Summer Affair