In a brief prologue set on April Fools' Day, two unidentified men, later revealed to be vice officers, deliberately drive a burnt-orange Camaro into a motorcyclist on Ventura Boulevard, forcing him into oncoming traffic. The driver, Ellis, smiles as the crash happens behind them, having eliminated what he calls "a problem."
Harry Bosch, a recently retired LAPD homicide detective, meets his half-brother Mickey Haller, a defense attorney known as the Lincoln Lawyer, at the Criminal Courts Building in downtown Los Angeles. Haller wants Bosch to investigate the case of Da'Quan Foster, a former gang member turned painter accused of raping and murdering Lexi Parks, a West Hollywood assistant city manager. The DNA evidence appears overwhelming: Foster's semen was found on and inside the victim. Haller insists Foster is innocent, but his regular investigator, Dennis Wojciechowski (known as Cisco), was badly injured after a driver forced him into oncoming traffic on his motorcycle. Bosch refuses. Working for a defense attorney would undo everything he stood for in 30 years of police work, a betrayal colleagues call "crossing to the dark side."
Despite his refusal, Bosch cannot stop thinking about the case. He learns online that Parks was beaten to death in her bed and found by her husband, Sheriff's Deputy Vincent Harrick, and that Foster, a self-taught painter who teaches art to children, was arrested 38 days later based on a DNA match from a prior arrest. Bosch calls Haller and starts asking questions about the evidence. His girlfriend, Virginia Skinner, a
Los Angeles Times reporter, ends their relationship. With his daughter Maddie preparing to leave for college, Bosch feels unmoored.
Haller delivers the discovery file, and Bosch begins reviewing the murder book, the complete investigative record. The Sheriff's investigators, Lazlo Cornell and Tara Schmidt, conducted a thorough investigation before the DNA match pointed them toward Foster: They cleared the husband, investigated sex offenders, and commissioned a behavioral profile of the killer. Yet Bosch identifies troubling gaps. Investigators found no connection between Foster and Parks, no video placing them in the same location, and no motive. He notices a tan line on Parks's wrist in crime scene photos indicating a missing watch, which appears on no property report. He also discovers a buried witness statement from someone who visited Foster's studio on the night of the murder and found him absent, potentially undermining his alibi.
Bosch agrees to interview Foster in jail. The thin, soft-spoken man is nothing like the imposing figure Bosch expected. When Bosch shows him a graphic crime scene photo, Foster recoils in genuine horror, convincing Bosch of his innocence. Under pressure, Foster reveals where he actually was that night: at a Hollywood motel with a transgender sex worker named Sindy. He kept the secret to protect his marriage, family, and community standing.
Haller then reveals what he had withheld: Sindy, whose real name was James Allen, was murdered in a Hollywood alley just days after Foster's arrest, eliminating the only alibi witness. Bosch realizes Haller manipulated him into discovering the case on his own, knowing a straightforward pitch would never have worked. Angry but invested, Bosch agrees to continue.
He contacts his former LAPD partner, Lucia Soto, who helps him learn about the Allen case. Allen was strangled with a wire in his room at the Haven House motel, and his body was dumped in a nearby alley. Soto risks her career to borrow the Allen murder book. Crime scene photos reveal no defensive wounds on Allen's hands, suggesting a second person restrained him while he was strangled. A neighborhood witness confirms hearing a car trunk close followed by two car doors, corroborating a two-killer theory. Bosch also notes a 14-month gap in Allen's arrest record, suggesting Allen had been working as an informant for someone in law enforcement.
Bosch obtains surveillance footage from a camera at Hollywood Forever cemetery overlooking Haven House. Footage from the night of Parks's murder shows a white van matching Foster's vehicle entering the motel lot at 9:45 p.m. and leaving at 11:43 p.m., supporting Foster's alibi. An independent DNA lab hired by Haller confirms the match to Foster but also finds condom trace evidence in the semen sample, suggesting the DNA was collected in a condom and planted at the Parks crime scene.
Bosch traces the missing watch to a service center in Las Vegas. The Audemars Piguet timepiece was originally purchased by Dr. Schubert, a Beverly Hills plastic surgeon who sold his wife's jewelry to cover gambling debts. Parks had sent the watch for repair, and when the service center informed her it might be stolen property, she called the jewelry store where Harrick had bought it, Nelson Grant & Sons. Four days later, she was dead.
Bosch visits Nelson Grant & Sons and questions the evasive owner, Peter Nguyen. That same day, both Nguyen brothers are found shot to death in the store's back room. Bosch feels responsible for leading the killers to them. Under his Cherokee, he discovers a GPS tracker, confirming he is under surveillance.
Soto identifies the names behind a Hollywood Vice unit call sign that appeared repeatedly in Allen's arrest records: Don Ellis and Kevin Long. These are the same officers who arrested Haller on a fabricated DUI charge shortly after Haller took the Foster case. Bosch connects the threads: two murders, two brothers killed, two car doors in the alley, two vice cops. At a lot where LAPD stores undercover vehicles, he finds a dust-covered burnt-orange Camaro matching the car that ran Cisco off the road. Cemetery footage also shows the Camaro at Haven House on the night of Allen's murder.
Bosch confronts Dr. Schubert at his cosmetic surgery office and records the conversation. Schubert reveals the full extortion scheme: Ellis and Long secretly recorded a compromising sexual encounter involving Schubert and used the footage to blackmail him. Unable to access cash, Schubert gave them his wife's jewelry, including both Audemars Piguet watches, and they staged a fake burglary at his home. When Parks's inquiries about the watch threatened to expose the scheme, Ellis and Long killed her, framing Foster with DNA collected from Allen. They then murdered Allen to eliminate the alibi witness.
Ellis and Long, tracking Bosch via the GPS device, follow him to Schubert's office and breach the building. Schubert, ignoring Bosch's order to hide, opens the bathroom door and surrenders. Ellis shoots him three times. Bosch, positioned behind a folding partition, opens fire. Ellis uses Long as a human shield before dropping his wounded partner and fleeing. Bosch handcuffs Long and texts the recording to Haller before surrendering to Sheriff's deputies.
Long is charged with Schubert's murder, but the Sheriff's Department and LAPD refuse to drop the charges against Foster. That night, Ellis returns to Bosch's home and ambushes him on the back deck, intending to kill Bosch before fleeing to Belize. Nancy Mendenhall, an LAPD Internal Affairs detective who had given Bosch a ride home, notices the Camaro parked nearby and returns. She enters the house, approaches Ellis from behind while a Wynton Marsalis record covers her footsteps, and shoots him dead, saving Bosch's life for the second time.
Haller files an emergency motion to overturn the preliminary hearing based on new evidence. At a packed hearing before Judge Joseph Sackville, Bosch testifies about his entire investigation and introduces the Schubert recording. When lead investigator Cornell testifies that no condom was involved in the crime, Haller introduces the defense lab's analysis showing condom trace evidence matching the Rainbow Pride brand Allen kept in bulk at his motel room. The judge finds the new evidence compelling, dismisses the charges, and orders Foster's release.
In the courthouse hallway, Haller holds court with reporters while Bosch watches from the side with Maddie. Bosch tells Mendenhall he is finished with defense work and plans to return to restoring his old Harley-Davidson motorcycle. He invites her to go riding when the bike is ready, and she accepts. Bosch heads home with his daughter, acknowledging an unfamiliar feeling: happiness at hearing murder charges dismissed.