After three years out of the LAPD, Harry Bosch returns, to find the department a different place from the one he left. A new Police Chief has been brought over from New York to give the place a thorough clean-up from top to bottom. Working with his former partner, Kiz Rider, Harry is assigned to the department's Open-Unsolved Unit, working on the thousands of cold cases that haunt the LAPD's files. Harry and Kiz are given a politically sensitive case when a DNA match connects a white supremacist to the 1988 murder of Rebecca Verloren, a 16-year-old girl of mixed race. The detectives who worked the case all those years ago seem to have done a decent job, but something doesn't fit. Meanwhile, Harry's nemesis, Deputy Chief Irving, is watching him. In the new 'clean' LAPD, Irving has been sidelined to a meaningless job. Compelled by vengeance, he hopes that Harry will make a slip.