Here is a thriller that will satisfy fans of the genre. "Have Mercy on Us All" is a very well constructed novel that features more original characters than each other. Although one finds there on Adamsberg commissioner and his Danglard colleague, always turned to the bottle of white wine, but also new as Joss Breton crier or Lizbeth, the former prostitute. Vargas has the talent to make us discover in a few lines and we do enjoy them instantly. The plot takes place in Paris today, except that people lose their lives as if they were infected with the plague, which is rather unlikely in our time. Yet, the whole city is boiling, mysterious 4 are painted on each door (to protect from the virus) and murders continues apace ... So the plague in the 21st century hoax or reality? Fred Vargas tells us a lot about this terrible disease thanks to his profession medievalist archaeologist. We're really intrigued by this story, we suffer the defeat investigators face this great mystery, it's just masterfully told. To me, "Have Mercy on Us All" and "Under the winds of Neptune" are so far the two greatest novels of Fred Varges.