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.

A detail from Kent’s widow Alicia leads Bosch and the FBI to suspect a group of Sovereign citizens in connection to the stolen radioactive cesium and Overlook murder, but they clash over tactics, causing a deadly standoff. Maddie finds a puzzling omission in a trial transcript and Detective Vega is uncomfortable to learn she’s Billets’ "teacher’s pet."

When cops discover the body of a homeless man covered in radiation burns, the hunt for the cesium intensifies but Bosch and Edgar wonder if their assumptions about the crime have been wrong all along. Maddie’s discovery earns Chandler’s praise. DEA Agent Charlie Hovan discloses his connection to Jamaican drug dealers with possible ties to Edgar’s dirty cops.

Bosch is pulled away from the arson case to a double homicide in the Hollywood Hills and finds RHD Detective Jimmy Robertson on the scene. When the harassment of Lt. Billets escalates, Captain Cooper and Lt. Thorne are angry that she reported it to IA instead of talking to them. Maddie makes a shocking discovery. Bosch and Edgar try to get Alvarez to talk.

After discovering Alvarez has been transferred, Bosch enlists Chief Irving’s help. Pierce and Vega get a lead on the hitman. Billets reaches out to a former Hollywood cop for intel on Leonard and Norris. When Bosch and Edgar meet with Carl Rogers, Edgar lets a detail of the case slip, enraging Bosch.

Robertson and Bennett follow the hitman’s trail to Las Vegas, hoping to find a connection to Fowkkes’ other clients. When Billets performs a security evaluation at a local jewelry shop, she gets more than she bargained for. Irving gives Bosch an order, causing Bosch to lose faith in the system he has defended his entire career.

As Billets posts the Hollywood homicide detectives’ new assignments, Bosch puts a plan in motion to arrest Mickey Peña, leading to some severe consequences. Billets makes an impression and Maddie makes a decision about her future.