Private detective Cormoran Strike drives to Kent to see a new client, Decima Mullins. His below-the-knee prosthesis makes driving uncomfortable, and he misses his business partner, Robin Ellacott. Robin’s boyfriend, CID officer Ryan Murphy, called that morning to say that Robin was ill. Strike is in love with Robin and jealous of Murphy.

Strike has just returned from Cornwall after attending the funeral of his beloved Uncle Ted. He and his sister Lucy have inherited Ted’s house. Strike keeps a few of Ted’s possessions as a reminder of his uncle, including his “priest” (a fishing bludgeon).

Decima Mullins is a “pale, dumpy woman” (6) around 40 years old. Decima explains that the case involves individuals Strike knows: Valentine Longcaster and Sacha Legard—the half-brothers of Strike’s recently deceased ex-fiancée, Charlotte Campbell. Charlotte died by suicide a few months earlier, citing her continued love for Strike as a reason. Consequently, Charlotte’s family and friends blamed Strike for her death.

Decima believes the police incorrectly identified a man who was murdered in the vault of a silver shop six months earlier. The murdered man had been working at Ramsay Silver under the pseudonym William Wright. The police claimed that Wright was the armed robber, Jason Knowles. However, Decima believes that the body was actually her boyfriend, 26-year-old Rupert Fleetwood, and wants Strike to prove it.

Decima reveals she has a three-week-old infant named Lion, and Fleetwood is the baby’s father. She tells Strike he must not reveal Lion’s existence to anyone. Decima says that her father, Dino Lancaster, and half-brother, Valentine, disapproved of her relationship with Rupert, claiming he was a gold digger.

Rupert’s parents were killed in a skiing accident when he was two. He was subsequently raised by his aunt, whom he hated, in Switzerland. When he returned to the UK, Rupert took a job at Dino’s, a private members’ club in London, owned by Rupert’s godfather, Dino Longcaster. Decima insists that she and Rupert knew they were soulmates from the moment they met, and that he would not have abandoned her.

Before Rupert went missing, Decima’s father had reported him to the police for stealing a nef (a large silver ornament shaped like a ship). The nef originally belonged to Rupert’s father, Peter, but Dino won it in a game of backgammon shortly before Peter died. Rupert was also threatened by a drug dealer named Dredge after his housemate, Zac Lorimer, went to Kenya, leaving behind drug debts. Decima believes that Rupert took a job at Ramsay Silver under the name of William Wright, hoping to sell them the nef to pay off the debt. However, Dredge must have found him and killed him. Rupert’s aunt, Angelica Wallner, claims that her nephew has secured a job in New York, but Decima does not believe this.

Robin is in the hospital after collapsing from an undiagnosed ectopic pregnancy. A doctor explains that the chlamydia Robin contracted when she was raped as a 19-year-old has damaged her fallopian tubes. He advises 32-year-old Robin that if she wants children, she should consider freezing her eggs as soon as possible.

Robin does not want Strike or her parents to know about the ectopic pregnancy. She reflects on how she was forced to stop taking the contraceptive pill during her last undercover job investigating a cult at Chapman Farm. Robin and Strike successfully exposed the United Humanitarian Church for the sexual abuse of women and children and the murder of some of its members. The investigation was highly traumatic for Robin, who experienced two sexual assaults and was almost drowned while undercover.

Strike calls Robin to tell her about the case. He explains the police believe that Jason Knowles posed as William Wright so that he and his accomplices could rob Ramsay Silver. Immediately after the murder, the tabloids ran sensationalized stories concerning the Freemasons, as Ramsay Silver specialized in masonic silver and was located by the Freemasons’ Hall. However, press interest soon died when the police identified Wright as Jason Knowles. The case’s lead investigator, DCI Malcolm Truman, insisted that the murder had nothing to do with Freemasonry. Wright’s murderer remains at large, and the stolen silver is unrecovered.

Robin tells Murphy she must have become pregnant on the night they argued after she feared the condom he used had split. Murphy is in recovery from alcohol addiction, and, on that night, Robin had suspected her boyfriend had been drinking. Murphy had angrily denied the accusation, claiming he was under pressure at work investigating a harrowing gang-related shooting in which a young boy had died, and another had been blinded.

Strike looks at photographs of Valentine and Sacha, many of which feature his former fiancée, Charlotte. Comparing pictures of the handsome actor Sacha to his cousin, Rupert, Strike can see no family resemblance. Rupert, like Decima, was ordinary-looking and round-faced.

Kim Cochran, the detective agency’s most recently hired contractor, updates Strike on her surveillance of “Plug.” Plug’s uncle has hired the agency to investigate his nephew, who is a petty criminal and the sole parent of a teenage son. Unable to prove that Plug is stealing the savings of his mother, who has Alzheimer’s, Plug’s uncle hopes Strike and Robin can uncover proof of his involvement in another arrestable offence.

Strike has decided that, despite Robin’s relationship with Murphy and his own fear of compromising their business and friendship, he must tell her that he loves her.

Robin has secretly been plagued by nightmares and anxiety since her undercover experience in the cult. After her discharge from the hospital, she researches the silver vault murder online. Newspaper reports reveal that the body was eyeless, handless, and had been mutilated. The stolen silver comprised items from the collection of the explorer and freemason A.H. Murdoch. CCTV images of the man posing as William Wright were blurred, revealing only that he was short and stocky, bearded, and wore spectacles.

Kim calls Robin, mentioning that Strike has told her “all about” Ted’s funeral and seems depressed. Robin dislikes their new contractor, who has made her attraction to Strike clear and treats Robin dismissively. Robin recalls how she first accepted a date with Murphy to get over her secret love for Strike.

Strike is following the ex-wife of “Mr A,” a cricketer who has recently been the subject of unflattering articles in the press. Mr A has hired the agency to prove his ex-wife is having an affair with the journalist, Dominic Culpepper, and that she has leaked these stories to her lover. So far, Strike has seen no evidence that his client’s suspicions are true.

Murphy is stressed as the press criticizes the police’s failure to bring the gangland-shooting killer to justice. He is wary when Robin asks him about the silver vault case, suggesting that Strike wants to upstage the Metropolitan Police. Finally, he agrees to ask a female colleague if forensics has verified that the dead man is Jason Knowles.

Strike hopes his 42nd birthday will pass unmentioned. However, his team presents him with presents and a birthday cake. Strike reveals that an old client, “Two-Times,” who consistently suspects his girlfriends of infidelity, wants them to follow his wife. Kim states that her police contacts are being evasive about the silver vault murder, and the lead investigator, Malcolm Truman, has been suspended.

Robin tells Strike that Murphy has sensitive information on the silver vault case and will only disclose it in person. Strike agrees to go to Robin’s flat that evening to meet Murphy.

Robin is anxious about Strike and Murphy meeting as the two men dislike each other. She has led Murphy to believe that Strike is still dating the lawyer, Bijou Watkins, although the affair was short-lived and ended some time ago. Robin suspects that Strike fears she will leave the agency if she marries and has children.

When Strike arrives, Murphy immediately asks how his relationship with Bijou is going. Strike covers for Robin, responding that things are going well. Murphy reluctantly reveals everything he knows about the silver vault murder. The murdered man had been working at Ramsay Silver under the false identity of William Wright for two weeks before he was killed. He was also renting a flat nearby. Police believe the murder took place just after one a.m., on Saturday, June 19, when an unidentified person was caught on CCTV entering Ramsay Silver before the camera was turned off. Wright’s body and the theft of the silver were discovered when the shop reopened on Monday, June 21. Police linked the murder to an ongoing undercover investigation into the role of Jason Knowles’s uncle in serious organized crime. They believe that Knowles had taken the job at Ramsay Silver so he and his family could burglarize the shop. They theorize that Knowles’s uncle suspected his nephew of leaking information to the police and had him killed. Fingerprints could not prove the murdered man’s identity, as his hands had been removed. DCI Truman announced the body belonged to Knowles without authorization, leading to his suspension.

Murphy admits that the police investigated two missing men who also fit the description of William Wright. Tyler Powell’s disappearance was reported by his grandmother, while Niall Semple, an ex-paratrooper, went missing at a similar time. Nevertheless, Murphy insists that the dead man is Jason Knowles. Asserting that he and Robin will determine that, Strike leaves, claiming he is meeting Bijou.

Strike secretly hopes the case will require him to work closely with Robin, giving him the opportunity to tell her he loves her. He is heartened by Robin’s willingness to continue with the case, despite Murphy’s disapproval.

Strike and Robin visit Ramsay Silver to meet its owner, Kenneth Ramsay. Robin has tentatively agreed to house-hunting with Murphy, despite misgivings about moving in with him.

Kenneth shows the detectives the vault where William Wright was murdered. He reveals that the dead man had the Salem Cross, a masonic hallmark, carved into his back and was naked except for a masonic sash when he was found. DCI Truman instructed Kenneth to keep these details quiet.

Kenneth explains that he hired William Wright to help his sister-in-law, Pamela Bullen-Driscoll, in the shop. Pamela helped at Ramsay Silver when she could. However, she and her husband, Geoffrey, had their own silver business, Bullen & Co., and a botched eye surgery had left Pamela visually impaired. On Wright’s last day at work, Pamela sent him to Bullen & Co to collect a silver centerpiece that had been sent to her own store in error. Ramsay blames his sister-in-law for the break-in, stating that she left early on Friday, allowing Wright to leave the premises without setting the alarm.

Wright’s search history on the work computer revealed that he had sought information on the Freemasons and consulted a website for individuals who had been wrongly accused of crimes. He had also emailed a man named Calvin Osgood, offering his help. Before they leave, Ramsay tries to sell Robin an orb charm. Robin likes the piece but cannot afford it.

Strike and Robin discuss the case at the pub. Online searches reveal little information on the disappearances of Niall Semple and Tyler Powell. The detectives speculate on why DCI Truman wanted to conceal the Freemasonry details of the murder. Strike observes that many masonic lodges have both criminals and police officers as members and decides to look into Truman. Robin is anxious about how Murphy will respond if he discovers they are investigating a police officer. She has already misled her boyfriend, telling him they’re investigating the disappearance of Rupert rather than the possible misidentification of the body in the silver vault. Robin finds a photograph of Tyler Powell on Instagram posted by “chloegriff.” Comments beneath it ask for the photo to be taken down, implying that Tyler did something terrible.

Strike observes that Charlotte’s half-brother—the actor, Sacha Legard—is likely to be hostile to questioning, as Charlotte believed Strike was in love with Robin. Robin escapes to the bathroom, angrily reflecting that if Strike had feelings for her, he should have expressed them when she was newly single after her divorce. While Robin is in the bathroom, Strike is disheartened to see a message from Murphy on Robin’s upturned phone with a link to a real estate site.

Strike researches the disappearance of Niall Semple, discovering he was last photographed on June 4 at an ATM with a briefcase handcuffed to his wrist. Semple was discharged from the army in 2014 after experiencing a brain injury. His wife, Jade, appealed for information when he went missing from their home in Crieff, Scotland. Strike notes that none of the articles state how Semple received his brain injury.

Strike and Kim attend a formal charity ball at The Dorchester to maintain surveillance on Mr. A’s ex-wife. Kim wears a revealing dress and makes Strike uncomfortable by flirting with him. She also tells Strike about her love life, describing how her ex-boyfriend, Ray, turned up at her door begging for a reconciliation. Strike is confronted by Nina Lascelles, Dominic Culpepper’s cousin, with whom he had a brief sexual relationship. Kim pretends to be Strike’s current girlfriend and suggests they go home. As they leave the event, Kim reveals that she has acquired photographic evidence that Mr A’s wife is having an affair with Lady Violet, the wife of Dominic Culpepper.

Robin receives a call from fellow detective Midge, complaining about Kim. Midge says Kim has been bragging about the charity ball, revealing that she met an ex-girlfriend of Strike’s and claiming that Strike shared intimate details with her. Midge asks if Strike and Kim are having an affair. Robin is horrified at the suggestion and ruminates on which of Strike’s many former girlfriends attended the charity event.

Strike and Robin meet to investigate the apartment block where William Wright lived. Strike pays Mandy and Daz, the couple who rent the flat below Wright’s, for any information they have on the dead man. Daz describes Wright as looking like a character from the game “Guess Who,” with a beard, thick glasses, and a fake tan. He was well-built and had a set of weights delivered while he lived there. Wright asked Daz and Mandy not to reveal his whereabouts if anyone came looking for him. One evening, Wright bought some cannabis from Daz and spent the evening with them. He said that he was waiting for his girlfriend to move in with him and talked about joining the Freemasons for protection. He also claimed he knew what had happened to someone called Rita Linda. On the evening Wright was killed, a dark-haired woman with a non-British accent let herself into Wright’s flat with a suitcase. When she left, she was struggling to carry the case and got into a silver-colored car. Early the next morning, a curly-haired man wearing sunglasses entered Wright’s flat and dragged a heavy suitcase down the stairs. He was driven away in the same silver car by the dark-haired woman. Mandy and Daz admit that they did not share this information with the police.

Robin sees a message from Kim appear on Strike’s phone that contains the words “SO SEXY.” When Strike suggests debriefing in the pub, Robin states she is going to view a house. Strike looks at Kim’s message: “He looked SO SEXY in his dinner jacket” (141). It is followed by an apology from Kim, claiming she meant to send the message to a friend.

Robin sits alone in a pub after visiting an unpromising property with Murphy. Strike, who is alone in a different pub, texts her with the details of “Abused and Accused,” the website Wright visited on the workplace computer. In an old post, one contributor, “AustinH,” claims that his girlfriend’s father is spreading false rumors about him. Robin is relieved when Strike states he will pass the information Mandy and Daz gave to Wardle, his police contact. During their exchange, Strike asks Robin what she thinks of Kim, realizing that his partner saw Kim’s message. Robin responds neutrally but is pleased when Strike says he finds Kim annoying.

Pat, Strike and Robin’s office manager, reveals that an unidentified man has left a threatening message, telling the detectives to “leave it” if they don’t want to get hurt. Strike speaks to Calvin Osgood, a music producer, whose identity has been stolen. Osgood’s online profile has been linked to an Instagram account that does not belong to him. Consequently, he receives strange emails addressed to “Oz,” such as someone enquiring if he wants to buy a van. Strike visits Oz’s Instagram page, which features photographs of glamorous events stolen from other accounts.

Strike and Robin survey the poor-quality CCTV footage from Ramsay Silver of Wright’s final day at the store. The footage shows a deliveryman arriving with three crates containing the silver Kenneth Ramsay had bought at an auction. Pamela unlocks the vault and calls the store’s cleaner, Jim Todd, to help Wright carry the crates to the vault. As they do so, Pamela serves a blonde customer. Once the customer leaves, Pamela disappears into the vault to check the delivered goods, realizing that a few of the items should have been delivered to Bullen & Co instead. She places these items in a bag for Wright, who leaves the store. Pamela then freezes as she looks at her phone. Wright returns with another large crate containing the Oriental Centerpiece, which had been mistakenly delivered to Bullen & Co. He and Todd carry it down to the vault, struggling under its weight. Pamela abandons the store in a hurry, and Todd and Wright remerge from the basement. Todd departs, and Wright leaves shortly afterward, without setting the alarm. In the early hours of the next morning, a figure enters the store and switches off the CCTV camera. A couple of hours later, the figure switches the camera back on, sets the security alarm, and leaves.

Strike meets Shanker, his contact in the criminal underworld. Shanker reveals that the drug dealer, Dredge, did not kill Rupert, as Rupert gave him £2,000 toward Zac Lorimer’s debt. He also warns Strike that he is placing himself in danger by investigating the body in the silver vault. Shanker reveals that the gangster, Lynden Knowles, had his nephew Jason killed, just as the police suspected. However, Jason was sent to “Barnaby’s” and was not the dead man in the silver shop. Shanker claims that the man who ordered the hit at Ramsay Silver is a powerful, wealthy Freemason, but he does not know his name. Before the two men part, Shanker confides that his girlfriend, Alyssa, has thrown him out after an argument. He intends to resolve the situation by buying her jewelry.

Midge reports that the previous night she followed Plug to an allotment where he visited a shed. The shed was padlocked, and it sounded as if a large animal was inside. As Robin follows Plug, Strike calls her from the luxury store, Liberty’s, where his new surveillance target, “Mrs. Two-Times,” is in the beauty salon. Robin assures Strike that she wants to continue with the case, despite the possible dangers, and advises him to Christmas shop while he is waiting for Mrs. Two-Times. Robin suggests buying scarves for his sister, Lucy, and his half-sister, Prudence, and advises him on which colors to choose. When Robin hints that she likes green and blue, Strike reveals he has already bought her gift.

Strike sees an article by Dominic Culpepper. The journalist portrays Strike as a womanizer who sleeps with clients and had an affair with Bijou while she was in a relationship with top barrister, Andrew Honbold. Strike realizes that Nina told Culpepper about his presence at the charity ball, and the journalist is targeting him for exposing Mrs. Culpepper’s affair with Mrs. A. The article includes a quote from former Conservative MP Lord Oliver Branfoot about the underhand methods of private detectives. Branfoot is a well-known public figure who often appears on humorous political quiz shows.

Robin reads the article about Strike and defends her business partner when Murphy comments on it. Robin has been attempting to contact Dilys Powell, Tyler’s grandmother. She receives a call from a young woman who says Dilys, her great aunt, is in the hospital. The girl states that she does not like Tyler and is not in contact with him.

Robin makes an impromptu visit to Pamela at Bullen & Co. Pamela is initially hostile, insisting she has nothing to say, and then bursts into tears. Robin is sympathetic and wins the store owner over by saying she would like the benefit of her specialist knowledge. Pamela reveals that she did not want to hire William Wright because his resume was full of spelling errors. However, Kenneth added Wright to the interview list without her approval, later claiming she was responsible for the mistake. Wright knew nothing about silver, and she even had to explain the significance of the lion passant, the hallmark of British silver, to him. Pamela states that the delivery of the Murdoch silver was several hours late, and the delivery driver, Larry McGee, was later fired by the auction house he worked for. She claims that she left Ramsay Silver early due to a sudden headache.

Strike learns that one of Plug’s associates has been prosecuted for animal cruelty. He calls an animal welfare charity to report his suspicion that an animal is imprisoned in the padlocked shed.

Leaving the office for Gibsons Auction House, Strike notices a blonde woman standing on the street corner. At Gibsons, Strike learns that Larry McGee recently died from a heart attack. The delivery driver had received several warnings about sexually harassing girls and young women. His employer also suspected him of stealing items from deliveries. He was fired immediately after the Murdoch silver delivery because he asked his co-driver to run an errand for him and then drove off without him.

When Strike returns to the office, he finds a hand-delivered note written in the Masonic code, the Pigpen cipher. Strike decodes the message, which states that the dead man in the vault was Dick de Lion, and someone “on TV” had him killed.

A man named Ralph Lawrence arrives at the office, hinting that he works for MI5. Lawrence assures Strike that the body in the vault was not Niall Semple. Strike resents Lawrence pressuring him to drop the case. He speculates that Semple worked for the SAS and received his brain injury in a secret operation that MI5 wishes to keep quiet.

On the way to view another house with Murphy, Robin receives a call from Dilys Powell. Dilys confirms that Tyler has not made contact since he disappeared from Ironbridge and only told their neighbor, “Griff,” where he was going.

Strike calls Robin, telling her about the contents of the coded note and revealing his discovery that Dick de Lion is a porn star. Strike and Robin agree to undertake an overnight research trip, visiting both Dilys Powell in Ironbridge and Jade Semple in Scotland.

Strike’s friend, Graham Hardacre, who works in the Special Investigation Branch of the Royal Military Police, confirms that Niall Semple was an SAS paratrooper, but the details of his brain injury are inaccessible. Meanwhile, Robin discovers that Sapphire Neagle, a teenager who contacted “Oz” on his fake Instagram page, is a missing person. She tells Strike that her Land Rover, used during many of their investigations, has been officially declared unroadworthy.

Strike visits Kenneth Ramsay’s cleaner, Jim Todd. Todd claims not to know Larry McGee, referring to the delivery driver in the past tense.

Robin visits Harrods to speak to Albie Simpson-White, a friend of Rupert’s who now works in the department store. He reluctantly agrees to meet Robin after his shift. The store is busy with Christmas shoppers, and Robin is taken by surprise when a man grabs her neck from behind. Forcing a small rubber gorilla into her hand, he states it will “‘appen again” unless she stops investigating. The gorilla is a reference to the rapist who attacked Robin years earlier while wearing a gorilla mask. Robin is shocked as her identity was concealed during the trial that led to her rapist’s imprisonment, appearing as “Witness G.” She does not tell Murphy about the incident but calls Strike.

Albie reveals that he met Rupert when they both worked as waiters at Dino’s. He states that Dino bullied Rupert, calling him the “jellyfish,” and gloating over winning the silver nef from Rupert’s father, Peter. Once Dino discovered Rupert was in a relationship with Decima, he persecuted them both, prompting Rupert to steal the nef. Albie dismisses Decima’s theory that Rupert was the body in the silver shop, but Robin is sure he is withholding information.