A short and punchy Harry Bosch mystery from Michael Connelly. It was originally published as a 16-part serial in the New York Times Magazine, but was expanded for the book version. It's fast-moving, taking place (roughly) over the course of a day, and there's a domestic terrorism angle; dink a few things, and it would make a marvelous season of 24.
Harry's called out from home at midnight to a crime scene at the "Overlook", a scenic spot in the Hollywood hills. A Porsche is parked with its hood up; the owner, Dr. Stanley Kent, is on the ground nearby with a couple of .22 slugs in his brain.
What makes it possibly more than an everyday homicide: Dr. Kent's specialty is handling radioactive material at various L.A. hospitals; if that material should happen to get into the Wrong Hands, it could be part of a dirty bomb that would kill a lot of people and render a significant portion of the sunny Southland uninhabitable for centuries. So the FBI gets involved almost immediately, in the person of Harry's onetime lover, Rachel Walling. And, sure enough, it's discovered that a large amount of cesium-137 has gone missing.
Harry is, as always, obsessed above all with bringing the killer or killers to justice. Everyone else, however, is concentrating on finding the cesium. Harry needs to spend nearly as much time fighting to keep his hand in the case as he does investigating the crime.