#10 The Drop by Michael Connelly

Bosch is still working cold cases and one comes up that looks like it might be a s case of lab contamination. As soon as this case comes up he gets pulled into an active case due to his old nemesis Irving asking him to work the death of his son. Bosch solves both cases but there are no easy endings in either case and one will certainly be brought up in the next book. Or at least I hope it will be.