One of the hundred books a year I read:

In the latest installment of the long-running Harry Bosch series, Renée Ballard has returned to the LAPD to head the Open-Unsolved Unit. She entices Bosch to come out of retirement as a volunteer on the squad, a deal he makes only if he can pursue a crime that has haunted him for years—the murder of an entire family.

She agrees, but only if he assists in focusing on the years-old murder case of a powerful local politician’s sister’s murder. That politician was instrumental in the reinstatement of the Open-Unsolved Unit. As they unravel that case, it threatens to become a political crisis within the department.

Bosch splits his time between the politician’s case and the murdered family. Both become explosive.