In 1993, Harry Bosch and his partner Jerry Edgar caught the Marie Gesto case. Marie was a young equestrian who went missing. Her car and clothing turned up in a garage but her body was never found. Bosch and Edgar had pegged a likely culprit — the son of a wealthy and powerful industrialist, but the detectives never found enough evidence to charge the suspect and the case went cold. Between then and the start of this novel, Bosch had retired from the LAPD and worked as a private investigator for three years but returned to the force because things didn't work out the way he thought they would in retirement. Now, nearing 60, Bosch is working in the prestigious Open-Unsolved Unit at Parker Center, going over cold cases with his most recent partner, Kizmin "Kiz" Rider. A serendipitous traffic stop in L.A.'s Echo Park neighborhood nabs Reynard Waits, a man with body parts in his van on the floorboard in front of the front seat. Detective Freddy Olivas is working the case and Richard O'Shea is the prosecutor assigned. Soon Waits has confessed to a string of slayings involving prostitutes and runaways, as well as to two earlier murders: one of a pawnshop owner during the 1992 riots, the other of Marie Gesto. When the Gesto case files are reexamined, it seems that Waits had called the police shortly after the murder, pretending to be a tipster, but Bosch and Edgar never followed up on the tip. Without this costly error, Waits could have been implicated within a week of Gesto's disappearance.