A Line to Kill

The third installment in Anthony Horowitz's Hawthorne and Horowitz mystery series continues the metafictional premise of the earlier books: A fictionalized version of Horowitz narrates his partnership with Daniel Hawthorne, a former Scotland Yard detective turned private consultant, as the two become entangled in another murder investigation.

The story begins when Anthony's publisher invites both him and Hawthorne to participate in a literary festival on Alderney, a tiny Channel Island with virtually no recorded crime. The festival is sponsored by Spin-the-wheel.com, an online casino run by Charles le Mesurier, a wealthy businessman who lives on the island. Anthony is reluctant, but Hawthorne agrees with surprising eagerness, raising Anthony's suspicions.

At the airport, Anthony meets the other festival guests: Marc Bellamy, a brash television chef; Anne Cleary, a children's author who writes the popular Bill and Kitty Flashbang series; Maïssa Lamar, an aloof French performance poet; and Elizabeth Lovell, a blind psychic who claims to communicate with the dead. Marc's young assistant, Kathryn Harris, handles logistics for his appearances.

On Alderney, a proposed electric power line called NAB (Normandy-Alderney-Britain) has bitterly divided the island. Le Mesurier, who stands to profit from selling land for the project, is widely seen as its driving force. At the opening reception, he greets Marc as "Tea Leaf," a nickname from their boarding school days, and taunts him with coded insults. Anthony witnesses le Mesurier grope Kathryn and notices a playing card tucked under le Mesurier's windshield wiper: the ace of spades printed with a skull and crossbones, a traditional death-card warning.

The next day, Elizabeth gives a sold-out performance in which she appears to channel the spirit of Anne's dead son, William, saying he died young after making a terrible decision. Anne, devastated, confirms William died of an overdose at university. At their own event later, Derek Abbott, le Mesurier's financial adviser, publicly accuses Hawthorne of assaulting a suspect in custody. Abbott, who uses a walking stick, was convicted of child pornography offenses, and Hawthorne allegedly pushed him down stairs during the arrest, permanently injuring him. Anthony realizes Abbott's presence is why Hawthorne came to Alderney.

That evening, le Mesurier hosts a lavish party at his mansion, The Lookout, which features a World War II-era gun emplacement at the garden's end, converted into a private retreat he calls the Snuggery. He drinks heavily, continues taunting Marc, and again corners Kathryn with unwanted advances. His wife, Helen le Mesurier, leaves the party early.

The next morning, le Mesurier is found murdered in the Snuggery, seated in a chair with a silver letter opener in his throat. His wrists and ankles are bound with parcel tape, but his right hand has been left free, palm up. His gold Rolex is missing, and a blow to the back of his head indicates he was struck before being restrained. Hawthorne finds a partial bloody footprint pointing toward the garden door and a two-euro coin behind a curtain; forensics later confirm the coin bears no fingerprints. Hawthorne tells Anthony the key to solving the case lies in understanding why one hand was left free.

Deputy Chief Jonathan Torode arrives from Guernsey and authorizes Hawthorne to run a parallel investigation. Evidence reveals cocaine in le Mesurier's blood, a will leaving everything to Helen, and that the parcel tape brand is unavailable on Alderney, suggesting the killer brought it. Helen admits she was in Paris with a French lover connected to the NAB project and insists she saw nothing from her bedroom window, though Hawthorne suspects she is lying.

Hawthorne privately tells Anthony the full story of Abbott's crimes: Abbott ran a media empire that concealed a child pornography website giving him access to children in Southeast Asia. Despite a lengthy investigation, he was convicted only of possession and served six months. Hawthorne is visibly affected but refuses to explain what makes the case personal.

Helen then vanishes. Text messages on her phone reveal she witnessed someone enter the Snuggery with her husband on the night of the murder and arranged to meet an anonymous correspondent. Her body is found in a cave near Abbott's isolated farmhouse, beaten to death with a rock. Colin Matheson, the festival organizer's husband, confesses that Abbott blackmailed him with footage of a sexual encounter between Colin and Helen in the Snuggery, coercing his political support for NAB.

Maïssa Lamar is unmasked as an investigator for the European Anti-Fraud Office (OLAF), sent to probe corruption surrounding NAB. She and her partner entered the Snuggery hours after the murder, found the body, and used le Mesurier's fingerprint to unlock his phone and download computer files, explaining the bloody footprints and other anomalies. Torode builds his case against Abbott, citing a £20,000 cheque signed by le Mesurier that Abbott presented to a bank.

Hawthorne then stages a séance with Elizabeth and proves she is not truly blind by throwing wine from a cling-film-covered glass at her face: She flinches. Elizabeth admits her sight partially returned after surgery and that she saw Abbott and le Mesurier walk to the Snuggery together on the night of the murder. Hawthorne also exposes Marc, revealing that "Tea Leaf" is cockney rhyming slang for "thief." Marc confesses to having kleptomania and admits to stealing le Mesurier's Rolex, which he threw into the sea. He recounts brutal bullying at boarding school, where le Mesurier led a gang that tied younger boys to chairs with parcel tape, mirroring the murder method.

Abbott is found dead at the base of a cliff, an apparent suicide, with a note saying he cannot return to prison. At his cottage, Hawthorne discovers footage proving le Mesurier orchestrated the seduction of Colin, using Helen as a willing participant, with Abbott serving as intermediary for a £20,000 commission. Anthony suspects Hawthorne warned Abbott that arrest was imminent, knowing Abbott would rather die than return to prison.

Weeks later, Hawthorne visits Anne in Oxford and dismantles her alibi. He reveals that Kathryn is Anne's daughter and that the murders were motivated by William's death. William did not have a drug addiction but a gambling addiction, destroyed by online casinos like Spin-the-wheel.com. When Anne received the festival invitation sponsored by le Mesurier's company, she planned revenge. Kathryn infiltrated Marc's operation to gain access to the island. At the party, Anne pretended to leave but slipped back and hid in the Snuggery. After Abbott departed, she and Kathryn stunned le Mesurier, tied him down, and forced him to gamble for his life with the stolen two-euro coin. He dropped it, unable to complete the toss. Anne killed him with the letter opener. She later recognized Helen as the glamorous public face of Spin-the-wheel's website, followed her to the cave, and killed her as well.

Anne reveals she is terminally ill with heart disease and has weeks to live. Hawthorne tells her she must go to the police herself. In an epilogue set a year later, Anthony reports that Anne confessed and died of a heart attack before trial. Kathryn was acquitted, the jury unable to prove she knew her mother intended murder. A posthumous postcard from Abbott reaches Anthony bearing four words: "Ask Hawthorne about Reeth" (372), referencing an unresolved encounter from a previous book in which a stranger called Hawthorne "Billy" in a Yorkshire village. Anthony finds nothing in his research, leaving the mystery of Hawthorne's hidden past unresolved.