While Chloe meets her former professor and mentor at a criminology conference in Belle-Ile-en-Mer, Rocher is dealing with the murder of a young babysitter who was beaten to death. The investigation turns out to be much more personal than it would seem, with unexpected consequences that create tangles in Rocher’s family ties. Stormy weather for Chloe as well, when the conference turns into a blood bath. Stuck on the little French island during a record storm, the criminologists are dropping like flies, and no one can figure out who the killer is.