A beautiful woman, Supergirl Francesca Farnese, appears out of nowhere on a Bavarian highway. She wears only an orange jumpsuit and wants to go to Washington. Playboy Charly first takes her to Lake Starnberg, where she meets best-selling author Evers. He immediately leaves his wife and travels with Francesca to Spain, where he negotiates a project with the American film producer Polonsky. No one remains unimpressed by the mysterious beauty. Supergirl remains elusive— she quickly disappears again, leaving behind a warning to the inhabitants of Earth that an attack from outer space is imminent...