New Year's Eve 2019. While Los Angeles celebrates, a fire breaks out in an East Hollywood apartment building killing several residents including a ten-year-old girl. When it’s determined to be arson, Detective Harry Bosch arrives on the scene but his partner, Detective Jerry Edgar, is noticeably absent.

Bosch and Edgar follow a lead in the arson fire case to the famed Magic Castle. Lt. Billets ruffles feathers in the officer ranks. After Chandler's new client Vincent Franzen spends a night in jail, he offers up a “muy grande pescado” as his get-out-of-jail-free card.

Bosch and Edgar track down La Mayorista, but Bosch asks Vega to assist after Edgar makes a costly error. Chandler and Maddie record Franzen’s statement for the SEC before Chandler stashes him away in a safehouse. Irving and Lopez discuss the arson case, each concealing their true agendas.

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.

After Maddie's involvement with the Franzen case leaves her exposed, she must testify before a grand jury to stay safe. Irving asks FBI SAC Brenner for help with Alvarez, learning something useful about Peña. The little tamale girl’s father pays Bosch a visit; his pain strengthens Bosch’s resolve to bring her killers to justice. Leonard and Norris push Billets to the brink.

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.