The body of a young girl is found in the Place Vintimille, in Montmartre. Megre goes over with Janvier, hoping that he won't meet Inspector Lognon, for it's his territory, and he'll feel he's being usurped, as usual. However, he's there. There's hardly a clue to the girl's identity except a label on her dress. Megre arranges to have her picture published in the papers, and goes to the dress shop. Irène's with Lognon. She remembers the girl, but not her name. Eventually a call comes in from a young girl with an address. The girl, Louise Laboine, had been boarding there for two months. Lognon had found a taxi driver who'd seen her outside the club Roméo, and later walking towards the Étoile. At the Roméo that night had been the wedding of Marco Santoni and Jeanine Armenieu.