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.

Bosch and Edgar uncover more details about the pharmacy murder and the opioid operation, while Detective Robertson works a tandem homicide. As Bosch pushes back against the deathbed confession at the heart of Borders' petition for release, he enlists the help of a longtime adversary. J. Edgar tries to persuade a former CI to cooperate with an investigation.

Bonner has a breakthrough in the Borders case. Christina Henry gets closer to uncovering police misconduct. Bosch realizes not everything with the Borders investigation was as it appeared. Edgar and Bosch get more than they bargained for in a return trip to the Garcia Clinic.

Stranded in the desert without backup, Bosch closes in on his murder suspects and learns more about Clayton. Worried about her dad, Maddie turns to Billets for answers. Billets, in turn, confronts Edgar about Bosch's rogue mission. Pierce and Vega head to Bakersfield to find Jose Jr. Anderson gets a tip about police misconduct in the Borders case, and Cronyn implicates Bosch.

Edgar interviews Clayton, desperate for details on Bosch's location in the desert. Meanwhile, Stones and Carter tell Bosch he's going home, but ominously take him up in the plane by himself. Billets resolves to turn a blind eye to the falsified crime stats. Crate plans Barrel's surprise retirement party. Irving makes his case to the DA, and Edgar gets closer to finding Bo Jonas.