This Night's Foul Work

On the outskirts of Paris, two men have been found with their throats cut. In Normandy, two stags have been killed and their hearts cut out. Meanwhile a seventy-five-year-old nurse who has murdered several of her patients has escaped from prison. Is there a connection between the three cases?
In this mystery, Commissaire Adamsberg is pitted against nemeses past and present: Ariane Lagarde, France's foremost pathologist and Adamsberg's enemy since they argued over a case twenty-three years earlier, and Louis Veyrenc, a new recruit with a grudge, who has been assigned the job of protecting the Commissaire's ex-girlfriend. As the different strands of Vargas's compelling story begin to intertwine, events move towards a gripping climax...