The case that Patrick Kenzie and Angela Gennaro, private detectives from Boston, are taking on is not an easy one. Psychiatrist Diandra Warren and her student son have mysteriously incurred the wrath of an Irish mob hitman and need protection. The investigation undertaken by the detectives coincides with an outbreak of bloody murders in the city, committed with extreme cruelty. The handwriting of the perpetrator points to one man - a serial killer who has been serving a life sentence for 20 years. Is it possible that he still has assistants at large? Shortly before death, all victims receive photographs of themselves by mail. This photo also comes to Angela. Detectives have less and less time to unravel the terrible mystery, the origins of which lie in a crime a quarter-century ago...