Jerome and Sophie are "strangers". They live in a world with rules that seem to them like so many shackles. They act strangely to the people they meet. They pass themselves off as brother and sister. A lot of people would rather accept the fiction than sanction a situation they would otherwise find shocking. Only Olivia is willing to accept the truth. Her taste for derision and her high spirits make it possible for her to transcend the couple's provocations and finally get the upper hand on them...