Lethal White

Lethal White is preceded by The Cuckoo's Calling, The Silkworm, and Career of Evil;[6][7][4][8] there are tentative plans to follow it with at least five more stories.[9][10][11][12] Rowling announced completion of the manuscript on 23 March 2018, after approximately two years of writing.[2][13][14] The book was released on 18 September 2018.[5] The book follows the private detective Cormoran Strike and his partner Robin Ellacott and is the longest in the series thus far.[15][13] The story begins with a Prologue following immediately after the conclusion of Career of Evil detailing events taking place at Robin's wedding reception.

At Robin Ellacott's wedding to Matthew Cunliffe, Cormoran Strike's capture of the Shacklewell Ripper the night before is already widely known, except by Robin. When Strike tells her that he had been trying to contact her during the week, she realizes that Matthew had deleted Strike's messages, which results in a serious row between the new spouses. Before Strike leaves, Robin accepts his offer of working as a salaried partner in the detective agency.

One year later, Strike has grown his detective agency to the point where he needs to hire more investigators. He receives an unsolicited visit from Billy Knight, a young man with a history of mental illness who claims to have witnessed a murder some years before, and the burial of the body in woodland, but is unable to provide any details before he runs out of Strike's office. While trying to establish Billy's identity, Strike meets Billy's older brother Jimmy and Jimmy's girlfriend Flick Purdue, radical left-wing activists who claim Billy is unstable and unreliable.

Strike's meeting with Jimmy does not go unnoticed. He is approached by Jasper Chiswell, a mercurial and scandal-plagued Member of Parliament serving as the Minister for Culture, whom Strike knew from investigating the death in combat of his son Freddie. Chiswell claims to have been blackmailed by Jimmy and hires Strike to investigate. He identifies Geraint Winn, husband of Minister for Sport Della Winn, as Jimmy's likely partner; where Jimmy wants money, Geraint wants to destroy Chiswell's career. Chiswell does not reveal what he is accused of, but does not deny the allegations and instead claims that what he did was legal "at the time". He asks Strike to find something he can use to mitigate the threat.

Strike places Robin undercover in Chiswell's office to carry out surveillance on Geraint. Robin accepts, but the undercover assignment places more strain on her already rocky marriage. She meets Chiswell's hard-working but under-appreciated daughter Isabella; his illegitimate son Raphael, who was recently released from prison after killing a woman by driving under the influence of drugs; and his young, unstable, histrionic second wife Kinvara. By bugging Geraint's office, Robin uncovers evidence that Geraint has been embezzling money from his wife's charities. Chiswell uses this knowledge to stop Geraint's blackmail, but Strike inadvertently invites media scrutiny when he stops Jimmy, Flick and other activists from humiliating Chiswell at a charity event.

Chiswell invites Strike and Robin to a meeting at a house he keeps in the city for business, apparently intending to fire them for the incident with the activists. Upon arrival, Robin finds Chiswell's body in the study, dead from suffocation and an overdose of anti-depressants. The Metropolitan Police rule his death a suicide, but Isabella is convinced that her father was murdered and that Kinvara is responsible, hiring Strike to investigate. Strike is frustrated by the way Isabella and the wider Chiswell family keep directing his attention to Kinvara, who they believe is trying to steal what remains of the family fortune from them.

Strike becomes convinced that the blackmail is connected to Chiswell's death. He eventually learns that Chiswell and Jack Knight, Jimmy and Billy's father, built gallows for export before the European Union banned the export of torture and execution equipment from member states. Two of these gallows, completed at the time of Jack's death, were sold to Zimbabwe, where one was stolen by rebels and used in the murder of a British teenager. The gallows could be traced to Chiswell because Billy had carved the White Horse of Uffington into it.

Meanwhile, Robin still struggles with post-traumatic stress disorder a year after her encounter with the Shacklewell Ripper, and Matthew continues to interfere in her business relationship with Strike. Robin separates from Matthew when she finds proof that he has been having an affair, intending to seek a divorce when she can afford it. Strike counsels her, drawing on his own experience of losing a leg. The two are forced to confront their personal feelings for one another, particularly after the reappearance of Strike's ex-girlfriend Charlotte Ross.

Strike discovers that Chiswell wrote Kinvara out of his will and bequeathed everything to his ten year-old grandson, while allowing Kinvara to continue living on the family estate for the rest of her life. However, Chiswell was careless and omitted certain items from the will, including a diamond necklace that is the last thing of value to the family, meaning that legally those items may be Kinvara's. Kinvara is unable to sell the necklace as the family are watching her, but Strike suspects there are other items of value Chiswell overlooked. He is drawn to a painting titled Mare Mourning and learns that it may be a lost George Stubbs artwork depicting a mare mourning a foal that died of lethal white syndrome. If its provenance were to be established, it would probably be worth over twenty million pounds.

Strike uses this knowledge to identify the actual killer: Raphael. Having never been accepted by the family and living in Freddie's shadow, Raphael tipped off Flick about a cleaning job at Chiswell's, expecting that she would find out about the gallows sales and tell Jimmy, who in turn demanded a 50% share of the profits. Raphael also seduced Kinvara and conspired with her to kill Chiswell; when Flick learned that Chiswell had inadvertently found out about the affair, Raphael was forced to act at once, before the provenance of Mare Mourning could be established and Chiswell's will amended. Kinvara confesses to her role, but Raphael lures Robin into a trap by sending her texts purporting to be from Matthew and asking to meet. He interrogates her about their investigation; Robin stalls for time by outlining everything in detail and predicting his plan to kill Kinvara. Strike realizes Raphael's duplicity when he notices that the text messages came from a disposable mobile phone used in the blackmail case. The police raid the houseboat Raphael is hiding on and arrest him before he can kill Robin.

In the aftermath, Strike and Robin approach Billy to discuss the "murder" he witnessed. With Isabella's testimony, Strike reveals that Billy was drugged by Freddie and Jimmy and that Freddie choked a young Raphael, but only until he passed out. Billy did see a burial, but it was the body of a small horse that Freddie killed in a separate act of cruelty. When Isabella defends Freddie's memory, Strike privately reflects on the way the upper classes defend their own from the indefensible. With Billy finally able to reconcile his memories, Strike and Robin leave together.

Rowling has confirmed that Lethal White will be adapted as part of the television series starring Tom Burke as Cormoran Strike and Holliday Grainger as Robin Ellacott.[16] Filming began in September 2019; although no exact release day has yet been publicly announced, the studio aims for a 2020 premiere consisting of four episodes.[17]