From amazon.com:
He walked away from the job three years ago. But Harry Bosch cannot resist the call to join the elite Open/Unsolved Unit. His mission: solve murders whose investigations were flawed, stalled, or abandoned to L.A.'s tides of crime. With some people openly rooting for his failure, Harry catches the case of a teenager dragged off to her death on Oat Mountain, and traces the DNA on the murder weapon to a small-time criminal. But something bigger and darker beckons, and Harry must battle to fit all the pieces together. Shaking cages and rattling ghosts, he will push the rules to the limit--and expose the kind of truth that shatters lives, ends careers, and keeps the dead whispering in the night...