Detective Harry Bosch learns the DA's office is examining new evidence which threatens to overturn an old case, potentially jeopardizing all of Bosch's other convictions. Meanwhile, a robbery turned murder at a local pharmacy exposes an opioid ring that drags Bosch down a dangerous path.

As Bosch digs into the Skyler case, he becomes more convinced that the Olmer confession is false. Robertson zeroes in on the identity of the pharmacy killers. Seeking a connection to the pill mill, Bosch goes undercover and befriends a fellow vet. Pierce and Vega work a lead on Jose, Jr. Edgar discovers that Gary Wise's life was more troubled than it appeared.