Have Mercy on Us All – Fred Vargas

Joss le Guern, one-time sea captain and now town crier in the 14th arrondissement of Paris, announces the items of news that are left (with a fee) for him to “cry” three times a day. A number of enigmatic and disturbing messages are being slipped into his box, and he is becoming alarmed. Commissaire Jean-Baptiste Adamsberg is visited by an extremely troubled woman. She keeps finding reversed 4s in black paint on the doors of her building. Between these strange marks and the town crier’s frightening bulletins, Adamsberg begins to sense a connection, even a grotesque menace. Then charred and flea-bitten corpses are found. The press seizes on their plague-like symptoms, and the panic sets in. Adamsberg, a detective of formidable intelligence and intuition but with a fragile memory, enlists a mediaeval scholar to help him unravel the messages delivered to the town crier and relayed to the neighbourhood