A Coast Guard helicopter arrives 22 minutes after Stilwell’s call. Quigley is dead, but Ramirez is alive despite massive blood loss from a bullet wound in her neck. Stilwell had been applying pressure to the wound with a dressing from a first-aid kit. The medical team stabilizes Ramirez and evacuates her to a mainland hospital. Left alone with Quigley’s body, Stilwell thinks of Quigley’s family. Stilwell’s superior, Captain Corum, calls to inform him that a homicide team is en route by helicopter.

After the homicide team arrives, Stilwell is taken to the substation and placed in an interview room to await debriefing. Knowing that he’ll be held accountable, he writes down every detail of the operation. He organizes the clutter in the room, which doubles as the island’s lost-and-found. Detective Ernie Simon, a former colleague from the homicide squad, conducts the first interview and reports that Ramirez is still alive. Simon says that he’ll interview Stilwell once without recording and then again while recording.

Simon questions Stilwell about the tip, which came from one of Quigley’s mainland confidential informants. Stilwell explains that Quigley vouched for the informant’s reliability from his time in the narcotics unit. Simon is suspicious about the tip and asks why Quigley was transferred to Catalina. Stilwell knows that positions at the Catalina substation are used to punish officers on the mainland. Stilwell recounts the story that Quigley told him about busting the sheriff’s nephew but admits that he doesn’t know the real reason. Simon implies that the true reason was something else before asking for a full account of the night’s events.

Stilwell recounts the story to Simon and two other investigators. Captain Corum enters, criticizes the messy lost-and-found room, and informs Stilwell that he’s a witness in the case and won’t be investigating it. Corum speculates that the deputies probably didn’t clear the plane properly and that someone hiding on board surprised Quigley and Ramirez, and Stilwell agrees. Corum questions whether Stilwell heard any gunshots. Stilwell heard nothing over the sound of his own pursuit and wonders if Corum is implying that Stilwell should lie. Corum dismisses Stilwell’s request to search for the escaped ATV driver, stating that mainland docks will be monitored instead. He also confirms that the ATV was reported stolen just before the incident by a man named Art Sellers. Corum warns Stilwell not to investigate the case and to direct all media inquiries to the mainland. He arranges for Simon to stay on the island and sleep in the substation’s bunk room to examine the crime scene at dawn.

After Captain Corum leaves, Stilwell shows Simon to the bunk room. He then reads Deputy O’Connor’s report on the stolen ATV, noting that Sellers lives on Clarissa Street and left the key in the vehicle. Stilwell goes home briefly, finding his girlfriend, Tash Dano, asleep. He sleeps on the couch for two hours and leaves before she wakes.

His first stop is the ferry dock, where he observes passengers boarding the first boat to the mainland. He gets the passenger manifest from Lindsey Fordham at the ticket window. A man named Kalas, a solo traveler on the waiting list, catches his attention. Fordham describes him as Latino with an accent. At Stilwell’s request, she calls Kalas back to the window and learns that his full name is Gonzalo Kalas. Stilwell follows Kalas from a distance, watches him make or receive a phone call, and sees him enter a restaurant, Original Jack’s Country Kitchen.

Simon calls Stilwell, asks if he wants to interview Sellers, and agrees to meet Stilwell at the restaurant to observe Kalas. Stilwell has the substation office manager, Mercy, run Gonzalo Kalas’s name and discovers that there’s a hold on him by US Immigration and Customs Enforcement (ICE). Stilwell and Mercy are both wary of involving ICE. He calls the listed ICE contact, Agent Jerry Gordon, who confirms that Kalas is a wanted cartel courier and possible sicario. Gordon agrees to text a photo.

Simon arrives, and Stilwell points out Kalas in a restaurant booth. He notes that there are two water glasses, suggesting that he might be meeting someone. They decide to wait for backup before moving in. Once two deputies are staged nearby, Stilwell and Simon enter the restaurant and corner Kalas in his booth. When Simon retrieves a backpack from under the table, Kalas denies owning it. Simon opens the bag and finds a black safety helmet identical to the one worn by the ATV driver. Kalas attempts to flee but is quickly subdued and handcuffed. He shouts that he’s a citizen and is being wrongly targeted by ICE. The deputies take him into custody and explain to the other customers that they work for the Sheriff’s Department, not ICE.

At the substation, Simon calls Captain Corum to report the arrest. He and Stilwell decide to bluff Kalas, who likely doesn’t know what happened at the airstrip after he fled. In the interview room, Stilwell tells Kalas that he’s being held on the ICE warrant but is also a suspect in the events at the airstrip. As part of the bluff, Stilwell falsely claims that they tracked him by camera from the moment he stole the ATV. Kalas asks for a lawyer.

Stilwell processes Kalas for booking. In the holding cell, Stilwell threatens him with a conspiracy to commit murder charge and then allows him one phone call. Kalas demands to use his own password-protected cell phone. Stilwell agrees, hoping to get the phone back unlocked. He gives the phone to Kalas while Simon prepares to investigate a Jaguar key fob found among Kalas’s possessions, suspecting that Kalas’s car is parked in Long Beach. Kalas makes a call in Spanish, which Stilwell monitors illegally. Hiding from the cell’s camera, Kalas locks the phone before returning it. Simon informs Stilwell that Corum is angry that Stilwell is investigating the case and wants a link to the substation’s interior cameras to monitor him.

Captain Corum calls and reprimands Stilwell for violating his order to not investigate Kalas, and he reiterates that Stilwell is to stay in the substation until the investigation is complete. Corum also instructs him to notify him if ICE attempts to take custody of Kalas.

Stilwell calls Adriana Quigley, the widow of the slain deputy, to offer his condolences. She blames Stilwell for not being with her husband and protecting him. After the call, Stilwell starts cleaning out the lost-and-found. He sorts through various items, preparing them for donation. He comes across an expensive camping backpack that was turned in two months prior. Inside, he finds a key ring with five keys, including a high-security Medeco key. He calls the locksmith listed on the key, a man named Barn, who traces it to a woman named Angela Metier. Barn recalls that the police had inquired about her years ago because she was a missing person and that her trail went cold on Catalina.

Barn tells Stilwell that he worked on Metier’s locks in March 2022 and that the police asked about her soon after that. He provides the name of the detective with the LAPD on the case: Bryce Kaufman of the Missing Persons Unit. Stilwell notices a jagged line drawn on the backpack’s spine panel.

Stilwell calls Detective Kaufman and leaves a message about finding Angela Metier’s backpack. He then calls Tash at the harbormaster’s office to ask about the camera archive. Knowing that Corum is watching on the substation cameras, Stilwell announces that he’s going to his office, sneaks out the window, and meets Tash in person to review the footage. The video shows a man in a baseball cap, sunglasses, and face mask sitting on a bench, leaving the backpack behind, and walking away. The image is too blurry for identification. Tash sends Stilwell a link to the video and a printed still image.

On his way back to the substation, Lionel McKey, a local reporter, calls Stilwell, who provides no comment. Kaufman calls Stilwell back, verifies Stilwell’s identity by calling the substation’s landline, and explains that the Metier case is unusual. An anonymous person occasionally calls him about the case, taunting him in a way that suggests he’s the one who took her. Kaufman reveals that the case was transferred to the Cold-Case Unit, run by Detective Renée Ballard, about a year ago. He also notes that Metier’s car, a Mini Cooper, was found in the Catalina Express parking lot, but there was no record of her buying a ferry ticket. Stilwell finds this odd, as one of the keys in the backpack was for a Ford.

Stilwell calls the LAPD Cold-Case Unit and speaks with a man named Laffont. Hesitant, Laffont puts Stilwell on speaker with Detective Ballard after Stilwell tells him about Angela Metier’s backpack. Stilwell explains that the backpack was deliberately left on a bench two months ago and that he has grainy video of the man who left it.

When Ballard seems skeptical, Stilwell reveals his hunch that one of their other cold cases involves a victim who drove a Ford. He also suspects that other connected cases involve bodies. Ballard agrees to bring him into the investigation in exchange for the backpack and keys, recognizing that his knowledge of Catalina is as valuable as her team’s knowledge of the case. Stilwell agrees to bring the evidence to her in person the next day.

Stilwell takes the first ferry to the mainland. His old Bronco fails to start and must be jump-started by the lot attendant before he can drive to the Ahmanson Center to meet with Ballard and Laffont. He delivers the backpack and key ring. Ballard agrees to read him in on the case as long as the LAPD remains the lead agency.

They explain that the investigation began when a hiker found the skeletal remains of a woman, Candace Neary, in Griffith Park. Neary, an avid hiker, had been missing since 2016, and her car, a Ford Mustang, was found at the park. Investigating Neary’s murder led them to identify three similar missing-persons cases, including Angela Metier. All victims were athletic women in their twenties with dark hair who were known to hike or camp alone. Because there are five keys on the ring, they now suspect that there might be a fifth victim. Ballard reveals that their initial profile of a stealthy, untraceable killer is now being reconsidered. The deliberate placement of the backpack suggests that the killer has a big ego and now wants to engage with law enforcement. They ask Stilwell to return to Catalina and look into her plans to hike the Trans-Catalina Trail.

Stilwell visits Deputy Ramirez, who’s in a medically induced coma. While there, Captain Corum calls to inform Stilwell that he’s back on full duty. Corum says that the review board felt Stilwell’s efforts to save Ramirez balanced out any operational mistakes.

When Stilwell asks whether they’re looking into Deputy Quigley and his informant, Corum is evasive. He refuses to disclose why Quigley was transferred to Catalina. He authorizes overtime to cover for the two missing deputies but again warns Stilwell that the airstrip shooting isn’t his case. He agrees to send replacements soon.

On the ferry back to Catalina, Stilwell calls Tash, an experienced hiker, and asks about the third leg of the Trans-Catalina Trail, which Angela Metier had planned to hike. Tash tells him that it starts at Hermit Gulch. Using the substation’s camera feed on his phone, Stilwell discovers that Kalas’s holding cell is empty.

He calls Mercy, who informs him that two ICE agents picked up Kalas that afternoon with a federal transfer order. Stilwell calls ICE Agent Gordon, who denies any knowledge of the pickup. Stilwell then calls Deputy Mason, who explains that two agents with badges presented a transfer order from a federal magistrate. Stilwell examines a copy of the order and notices that it’s from the Southern District of California, not the Central District where Los Angeles is located. He suspects that the signature page may have been taken from a separate document. He also questions Mason about Quigley, and Mason recalls Quigley saying that he requested the transfer to “lie low for a while” (79).

After Mason leaves, Stilwell reviews the substation’s security footage. It shows two men in unmarked raid attire with ICE hats entering, presenting paperwork to Mason, and escorting Kalas out of the building. Their faces are obscured by their caps. Stilwell calls Gordon again, who insists that Kalas isn’t in their system and that his agents didn’t make the pickup.

Realizing that Kalas may have escaped, Stilwell calls Detective Simon to report the situation. Simon agrees to inform Captain Corum and investigate the transfer. Stilwell calls Tash to ask more about the Trans-Catalina Trail. She suggests that an experienced hiker like Metier would start the third leg at Black Jack Mountain. He asks her if she remembers the search for Metier, and she recalls that Lionel McKey was “obsessed” with the case. Stilwell arranges for Tash to guide him on a hike of the trail the next day.

While studying a map of the island, Stilwell notices a vehicle-accessible road, Black Jack Road, that branches off the Trans-Catalina Trail near Black Jack Mountain. He calls Tash, who tells him that the road leads to a protected grove of rare Catalina ironwood trees. The trees are clonal, sharing a single underground root system, and climate change has been threatening the remaining groves.

Stilwell traces the shape of Black Jack Road from the map onto a piece of paper. He then calls Detective Ballard and sends her photos of the backpack. He points out the jagged squiggle drawn with a permanent marker on the pack’s spine panel. He texts her the photo of his tracing of Black Jack Road. Ballard confirms that the two images are a perfect match. Stilwell concludes that the killer has drawn a map on the backpack, taunting them by leading them directly to where he buried Angela Metier.

A search team, including Ballard, Stilwell, and a cadaver dog, search the ironwood grove, and Stilwell begins a careful excavation, uncovering human remains. They secure the scene and wait for a team from the medical examiner’s office to arrive. News helicopters begin circling overhead, and McKey appears at the crime scene.

Stilwell calls Captain Corum to update him. Corum is angry that Stilwell involved the LAPD without his knowledge and declares that while Stilwell can work the Catalina angle, he’s not to follow leads off the island. Ballard assures Stilwell that she will keep him in the loop. Stilwell speaks with McKey, giving him no information but agreeing to talk later if he can. He asks McKey about the original search for Metier four years ago, trying to learn if the grove was checked. McKey believes it was but has no specific details.

The remains are sent to the medical examiner’s office. Stilwell returns home, where Tash has made gumbo. He brings her a bouquet of flowers he picked from the grove. She identifies them as wishbones, her favorite flowers, and is touched. He apologizes for their hike being canceled, but she understands. He expresses his hope that Metier’s murder doesn’t discourage Tash from her love of hiking alone. After a shower, Stilwell feels the dread he has been carrying since the discovery of the body begin to lift as he settles into the comfort of home.