Troy Turner and Rand Duchay were barely teenagers when they kidnapped and murdered a younger child. Troy, a remorseless sociopath, died violently behind bars. But the hulking, slow-witted Rand managed to survive his stretch. Now, at age twenty-one, he's emerged a haunted, rootless young man with a pressing need to talk once again with psychologist Alex Delaware. But the young killer comes to a brutal end, that conversation never takes place. Or has...

Detective Harry Bosch investigates a cold case and the murder of a city councilman's son. The cases are unrelated but they twist around each other like the double helix of a DNA strand. One leads to the discovery of a killer operating in the city for as many as three decades; the other to a deep political conspiracy that reached back into the dark history of the police department.