Three wounds in a perfectly straight line was the bloody signature that marked victims from every corner of France who had been murdered at regular intervals over the course of thirty years. Commissaire Jean-Baptiste Adamsberg, the chief of police in Paris's 7th Arrondissement, is deeply and personally familiar with the case, and though others were also framed and convicted for these crimes, including his own brother, the Commissaire knows the true identity of the killer - and knows that the murderer died in 1987. All the more disturbing, then, is Adamsberg's discovery one morning of a fresh murder with exactly the same profile. Stunned into action - and himself a suspect - Adamsberg must confront the mysterious return of an old, familiar evil.