Craving a change in lifestyle, jewel thief and eight times-divorced Edouard (Jean-Paul Belmondo) leaves Paris for the Patagonian jungle. One day, while out gathering grubs, he makes the acquaintance of an extraterrestrial little girl (Thylda Bares) who materializes out of nowhere and proceeds to speak to him in perfect French. In short order, ambitious astronomer Dr. Margaux (Arielle Dombasle) -- who has long looked for evidence of extraterrestrial life -- arrives on the scene as part of a top-secret mission, complete with her nasty secret service operative (Patrick Bouchitey). Margaux and Edouard gradually learn that the little girl, called Lulu, is from a small planet populated by child-sized beings who take special pills to ensure eternal life. Lulu, who came to Earth to experience human emotions, left her pills at home and is aging at a rate of ten years every hour.
by Rebecca Flint Marx synopsis