Bosch is a homicide detective in Los Angeles. He is haunted by an incident two years ago, in which he may have killed a suspect, and for which he has to appear in court. At the same time, he investigates several murders, including that of a boy whose skeleton is found in the forest. The boy turns out to have been murdered in 1989 or earlier and to have been so terribly mistreated (more than forty broken bones, partly healed, partly more recently at his death), that his exact age can no longer be determined.