Hugues (Jean-Claude Carrière), a veterinarian, contacts an agency for people who are seeking marriage. Through the agency, he meets and marries Jeanne (Anna Karina), a woman with a large house where he can use the space to care for animals. Later, he turns jealous and suspects his wife has a secret life. She discovers he has followed her and retaliates by giving one of his poisonous snakes to a zoo. Eventually, the two lovers reconcile to combine forces against the animals that may be extraterrestrials who have taken on human form in this fantasy comedy effort.