Nightshade

Nightshade (2025) is a detective novel by American mystery writer Michael Connelly, who is best known for his novels featuring Harry Bosch. The novel introduces a new hero, Detective Stilwell, who is posted on Catalina Island after a scandal on the mainland. The discovery of a mutilated buffalo corpse sends Stilwell on an investigation that exposes a scandal that threatens the idyllic island’s reputation. Major themes in the novel include Structural Inequality in the Criminal Justice System, The Impact of Tourism on Communities, and The Dangers of Ingroup Biases. 

This guide refers to the 2025 Hachette Book Group e-book edition.

Content Warning: The source material and guide feature depictions of graphic violence, death, death by suicide, animal death, child sexual abuse, racism, gender discrimination, and cursing.

Plot Summary

On Catalina Island, Detective Stilwell hurries through his administrative duties in order to execute a search warrant on the outskirts of the town of Avalon. When he finds evidence of blood on a saw at the Island Mystery Tours warehouse, he begins to suspect that the owner, Oscar “Baby Head” Terranova, is involved in the recent beheading of a federally protected buffalo on the island.

The body of a young woman with a purple streak in her hair is found in the Avalon harbor. Avalon mayor Doug Allen warns Stilwell to keep the investigation quiet so as not to interrupt tourism over the busy weekend. Stilwell’s old rival, Detective Rex Ahearn, is sent from the mainland to lead the investigation. Although Stilwell promises to be professional, Ahearn holds a grudge and insists that Stilwell not interfere in the investigation or else he’ll be fired. Despite Mayor Allen’s best efforts, the body makes front-page news alongside a report about the headless buffalo. Meanwhile, a man named Merris Spivak is detained after assaulting a police officer.

When a statue is stolen from the prestigious Black Marlin Club, Stilwell is shocked to learn that the accused, a woman named Leigh-Anne Moss, had a purple streak in her hair. At the club, Stilwell learns that Moss was fired for being overly flirtatious with members. Club manager Charles Crane suggests that Moss was looking for a wealthy man to pay her bills and that she stole the statue in anger after being fired.

With the help of his girlfriend, assistant harbormaster Tash Dano, Stilwell finds footage of suspicious boat activity at the Black Marlin Club the week Moss died. Stilwell theorizes that Moss was killed when she was hit in the head with the missing marlin statue and then was dumped in the ocean from a sailing yacht called the Emerald Sea. Meanwhile, Henry Gaston, a worker whom Stilwell questioned while searching the Island Mystery Tours warehouse, is reported missing.

Stilwell travels to the mainland to interview Moss’s ex-boyfriend, who claims that they split because of her habit of chasing wealthy older men. The owner of the Emerald Sea, Mason Colbrink, insists that he was on the mainland that weekend and did not authorize the boat to leave the harbor. When Colbrink agrees to let Stilwell search the boat, they find that the sail bag and possibly the anchor have been replaced, suggesting that the Emerald Sea was involved. Stilwell interviews the Emerald Sea’s sole crewmember, Duncan Forbes, who denies knowing Moss and provides an alibi for the weekend she disappeared. He reveals that the Emerald Sea’s sail bag and anchor were stolen while the ship was docked at the Black Marlin Club and that he replaced them without telling Colbrink.

Stilwell is unexpectedly confronted by his commanding officer, Captain Corum, who chastises him for pursuing the investigation. Stilwell presents his evidence and convinces Corum to put him on the case with Ahearn and his partner, Frank Sampedro. After an awkward first meeting on the mainland, the men grudgingly agree to work together. Back on Catalina, Stilwell interviews Moss’s former roommate, Leslie Sneed, who allows Stilwell to search Moss’s room. He finds a pair of expensive designer shoes and a note from a man named Daniel Easterbrook.

Henry Gaston appears at the police station, desperate for protection from “Baby Head” Terranova. Gaston reveals that Terranova paid him to mutilate the buffalo in order to stir up interest in his mystery tours. He also implicates the mayor in a plot to force through an unpopular proposal to build a Ferris wheel in Avalon. While both men are locked in the station, Merris Spivak kills Gaston and escapes with the only record of his confession. When Captain Corum decides to pin the mutilation on Gaston and not arrest Terranova, Stilwell leaks the truth to journalist Lionel McKey.

That night, Stilwell receives a call from Spivak, who has kidnapped Tash Dano and demands that Stilwell destroy the blood-stained saw he took from the Island Mystery Tours warehouse. Stilwell uses location-sharing data from Dano’s phone to find and rescue her, killing Spivak in the process. He is removed from the Moss case and placed on administrative leave while Internal Affairs investigates the shooting. Nevertheless, he travels to the mainland to interview Daniel Easterbrook, who claims that he and Moss were in love and that she was not fired but quit her job to be with him. He suspects that Black Marlin Club manager Charles Crane may have lied to him. Furious that he is still pursuing the case, Dano grows distant.

At a mandated therapy session, Stilwell is declared fit for a return to duty. The next day, Easterbrook is found dead in his home, and the Los Angeles County police announce that he is their leading suspect in the Moss murder. Stilwell calls Captain Corum and accuses Ahearn of pinning the murder on an innocent man in order to close an easy case, insulting both men.

Stilwell begins to suspect that Terranova must have a source inside law enforcement. District Attorney Monika Juarez admits that Terranova was blackmailing her for information and that she suspects he is also blackmailing the mayor. Terranova offers evidence that Mayor Allen had Henry Gaston killed to prevent him from testifying in the buffalo-mutilation case. He is granted immunity in return for his cooperation in the indictment of Mayor Allen.

Meanwhile, Stilwell convinces Moss’s former roommate, Leslie Sneed, to text Charles Crane and imply that she knows he was involved in Moss’s death. In a conversation secretly recorded by Stilwell, Crane implies that he had an affair with Moss and killed her when she broke up with him and quit. Stilwell arrests Crane and tries to goad him into a full confession but fails.

Terranova’s testimony leads to the arrest of Mayor Allen, who claims innocence and accuses Stilwell of corruption. Stilwell leaks a tip to Lionel McKey, who captures embarrassing footage of the mayor being removed from City Hall in handcuffs. In the Epilogue, Stilwell finds Tash Dano at a secluded camping spot, where they rekindle their relationship.