This John Derek opus shows off his latest protegee/wife, Bo Derek. Set on a lush Greek island, the story concerns a sister (Bo Derek) and brother (Peter Hooten), who return home after years abroad. Falling under the island's erotic spell, the girl and boy discover that their love goes beyond filial. The incestuous nature of the story evaporates when it is discovered that the two aren't actually related after all. Filmed in 1973, Once Upon a Love wasn't released until after the Dereks' 1981 Tarzan the Ape Man.