Original Sin.

Commander Adam Dalgliesh is consulted by one of his literary heroes when Peverell Press staff fall victim to a rash of hate mail. When the body of an editor is discovered and another member of the venerable firm is found dead soon after, Dalgliesh and his team—Detective Inspectors Kate Miskin and Daniel Aron—turn to the past to track down a murderer who seems prepared to kill and kill again.