Muriel's twin sister (a truly sexy Cathy Ménard) has just taken her own life, and at the funeral, she receives a letter from her in which she expresses the reasons why she chose a depraved life as a means of distinguishing herself and distancing herself from the decorum imposed by more comfortable surroundings. Sandra has left Muriel the key to her apartment and, therefore, the opportunity to venture into her wild world by assuming her sister's identity. The ease with which Muriel accepts this offer, from the outset, seems a paradigm of Kikoïne's cynical view of humanity and her false sense of dignity. Although Muriel is supposedly a virtuous woman, she quickly adapts to a veritable gallery of dishonest characters, each more sordid than the last, starting with the stuttering and stingy janitor, who demands payment of the outstanding rent in kind. Gérard Kikoïne always felt more comfortable exploring the dark side of human sexuality and the often-unprecedented lengths to which people were willing to go to maintain a superficial semblance of respectability in a deeply hypocritical society. The well-to-do middle class, the natural habitat of his fellow filmmaker at Alpha France, Claude Bernard-Aubert (AKA Burd Tranbaree), proved to be his favorite target, turning it into a kind of sexual saga. Kikoïne went to great lengths here to depict sex as grotesque, an irresistible driving force that reduces the characters to caricatures. Adopting a superior position as narrator of this farce of human weaknesses, this approach is emphasized by Gérard Loubeau's spectacular camerawork, which prioritizes the distancing effect of long shots and the distortion of wide-angle shots. One of the best in fornication cinema.