In The Drop, Harry Bosch is working for the cold cases department and suddenly finds he is called on to investigate two cases at once. The first is an apparent suicide of the son of a leading politician – with all the accompanying fallout dealing with a long-term enemy of the police force could bring. The other is a puzzling murder in which the suspect matching DNA from the scene would have been a child at the time of the crime. In this book, Harry meets Hannah Stone, the therapist of one of the suspects. It also features his daughter, Maddie.