Thirteen-year-old Lou Bertignac is a gifted but lonely child. At high school she is already in fifth grade, two years ahead of the other students, but she has no friends. At home, she does not feel too good between a father who is a stickler over principles and a deeply depressed asthenic mother. When the French teacher asks the class to write an essay and to make a presentation about a subject of their choice, Lou chooses homelessness. She hopes to be helped by a homeless girl she has noticed at the Gare d'Austerlitz, who begs and asks for cigarettes there. Nora, nicknamed No, reluctantly accepts to be interviewed by the serious-minded child. They meet several times at the café and although No is intemperate and unpredictable, a little frightening in fact, Lou soon cannot do without her any more...—Guy Bellinger

Lou is what they call a gifted child. She's 13, she's skipped two years in school. Her mom lives in a fog of tranquilizers, since she lost Lou's sister when she was a baby. Lou doesn't have many friends and she has a keen sense of what's wrong in the world. She has to give a presentation about a young homeless woman and she's already spotted a potential candidate at the Gare d'Austerlitz. A young woman who begs, scavenges cigarettes and hangs around the station with two guys and a dog. She's 18 and her name is No, No for Nora. Lou finds soon she can't get along without her. However, No is unpredictable: she grew up in care homes and she doesn't fit in. One day, she disappears and Lou doggedly searches for her, convinced they need one another. When No reappears in a terrible state, Lou knows what she has to do. No must come and live with her. Now she just has to convince her parents and to do this, she needs the help of Lucas, the big boy, the class troublemaker who she finds so intimidating.—Anonymous