Paris comes under siege when someone starts killing women on the streets one summer - and Maigret must hatch a plan to lure the murderer out.
It was 4 August. The windows were wide open but brought no relief, since they allowed in even more warm air, which seemed to be rising from the melting tarmac, the burning hot stonework and even the Seine itself: one could imagine the river steaming like a pan of water on a stove.
The first message sent to Tom Thorne's phone was just a picture - the blurred image of a man's face, but Thorne had seen enough dead bodies to know that the man was no longer alive. But who was he? Who sent the photograph? And why? While the technical experts attempt to trace the sender, Thorne searches the bulletins for a reported death that matches the photograph. Then another picture arrives.