Harry Bosch is nearing retirement. As such, he has been transferred to the Open-Unsolved Unit, what many call the Cold Case Unit. He has a new partner, Soto, who made detective after being involved in a shoot-out where she killed two gunmen in the midst of a robbery. The case they catch is definitely a cold case and one that most detectives would have no chance of solving.

Ten years ago on a weekend afternoon, shots rang out in a crowded downtown plaza. The man who was shot, a mariachi player, survived but with a bullet lodged in his spine that paralyzed him. The current mayor used this crime and his determination to make sure that the Hispanic community received justice as a lynch pin of his successful campaign for mayor. Now that man has died after ten years, the bullet he took that day finally killing him.

There is pressure from the mayor's office to solve the crime, although it is an almost impossible one. As Bosch and Soto work the case, they start to see that it may be tied to another, older, even bigger crime. A fire was started in a low-rent building that ended up killing six children in a daycare located there. Soto had been one of the children there that day but survived; the crime providing the impetus for her choice of a profession. Are the two cases related and can either be solved after all this time?

This is the seventeenth Harry Bosch novel. Harry is winding down his career but that doesn't mean his passion for solving crimes has diminished even a little. He is cynical about the city and its government and never quick to warm up to anyone but as he and Soto work he realizes that she is a detective he can respect. This book is recommended for mystery readers.