LAPD (Los Angeles Police Department) detective Harry Bosch is back on the force after a three-year retirement. Assigned to the Open-Unsolved Unit (cold case squad) and teamed with former partner Kizmin "Kiz" Rider, Harry's first case back involves the murder of 16-year-old high school girl Rebecca Verloren in 1988, reopened because of a DNA match to blood found on the murder weapon. The blood on the gun belongs to a local low-life white supremacist, Roland Mackey, a fact that links him to the crime via the victim's biracial family. But the blood indicates only that Mackey had possession of the gun, so how to pin him to the crime? Connelly meticulously leads the reader along with Bosch and Rider as they explore the links to Mackey and along the way connect the initial investigation of the crime to a police conspiracy orchestrated by Bosch's nemesis Irvin Irving to cover up the ties of a ranking officer's son with a neo-Nazi group. Most striking of all, in developments that give this novel astonishing moral force,[according to whom?] the pair explore the "ripples" of the long-ago crime, how it has destroyed the young girl's family—leaving the mother trapped in the past and plunging the father into a nightmare of homelessness and alcoholism—and how it drives Rider, and especially Bosch, into a deeper understanding of their own purposes in life.