Jeffery Deaver

In the second, prizewinning installment of the Duca Quartet from the godfather of Italian noir, doctor-turned-investigator Duca Lamberti uncovers a complex web of murder, betrayal, and revenge in Milan's criminal underworld. On a quiet night at the edge of Milan, a car rolls into a canal; its two occupants, Turiddu Sompani and Adele Terrini, quickly drown. The only witness is a young woman, an American.
She has committed the perfect murder. A few days later, a man comes to see Duca Lamberti, former doctor, at his shuttered practice. Though Duca has lost his medical license, he is still in demand with those at the fringes of the law-for instance, young women in need of delicate services. This unwelcome new visitor comes with a request on behalf of his lover, and tries to ingratiate himself by mentioning a shared acquaintance: Turiddu Sompani.
The whole business makes Duca's skin crawl, and he immediately takes his suspicions to the police. But Duca can't wash his hands of the matter, and soon finds himself heading an investigation that links Sompani with several other curious deaths. As Duca is drawn further into the case, he uncovers a sprawling criminal enterprise rent by double-crossing and retaliation-one that might just tear apart the city of Milan itself. First published in 1966, a sensation in Italy, and winner of the French Grand Prix de Littérature Policière, Traitors to All is a gripping novel that helped to cement Giorgio Scerbanenco's position as a master of international crime fiction.