There's a deadly August heatwave and Inspector Aliette Nouvelle is looking forward to her upcoming vacation. She's been working hard, without much reward. Denied promotion to the coveted Commissaire's post — which seemed practically guaranteed before the dubious Jacques Normand affair — she now finds herself working under the new acting Commissaire, Claude Neon, her former assistant.

It's hard not to be bitter. When Claude presents Aliette with the report on the murder of a Marilyn Monroe look-alike who had been the star attraction at the upscale brothel known as Mari Morgan's, he assures her it's an open-and-shut case. The prime suspect is already sitting in a cell awaiting questioning and psychiatric evaluation. But Aliette's instincts tell her that this is not quite as simple as it appears. Claude doesn't always agree with Aliette's methods, but he has learned from first-hand experience to trust her instincts: she's still the best cop in la brigade. He reluctantly hands over the case and Aliette embarks on an unsettling journey, the strangely uncooperative putes' clues leading her to a sisterly cult and the ancient goddess who rules it.