In the alley in front of his tenement building, ageing bachelor Seligman finds a young woman covered in blood. He takes her to his apartment where Joe tells him about her life, her experiences with men and her insatiable appetite for sex. She first learns about the physiology of the female body from reading her doctor father’s medical books. Although not yet an adult, she and a girlfriend embark on a round of sexual escapades, seducing men in flats, train compartments, bars and offices. Jerôme, with whom she has a child, is the one constant in her life. But her happiness is fragile.