The Ink Black Heart

The sixth installment in the Cormoran Strike series follows private detectives Cormoran Strike and Robin Ellacott as they investigate the anonymous online tormentor of a murdered animator, a case that draws them into a world of toxic fandom, far-right terrorism, and concealed identities.

The novel opens with Strike and Robin celebrating Robin's thirtieth birthday at the Ritz in London. The two are business partners and self-declared best friends who share an unspoken mutual attraction. As they wait for a taxi, Strike moves to kiss Robin. She involuntarily flinches, and the moment passes. In the following weeks, both adopt an increased reserve. Strike begins secretly dating Madeline Courson-Miles, a jewelry designer. Robin spends a skiing holiday brooding over what happened and whether she is in love with her partner.

Interspersed with these personal developments, the novel introduces The Ink Black Heart, a cult animated cartoon set in Highgate Cemetery created by Edie Ledwell and Josh Blay. The cartoon attracted a passionate fandom and an anonymous figure called Anomie, who built an elaborate multiplayer game around its characters with a collaborator called Morehouse. After Edie criticized the game in an interview, Anomie launched years of relentless harassment: leaking her personal information, spreading lies, and inciting fans against her. Two game moderators called LordDrek and Vilepechora fabricated a dossier falsely proving Edie was secretly Anomie and manipulated another moderator into delivering it to Josh, who believed it. Edie attempted suicide in May 2014. A far-right terrorist group called The Halvening had also targeted Edie, aiming to drive her to suicide through coordinated online abuse.

In late January 2015, a disheveled Edie visits the agency, begging Robin for help identifying Anomie. Robin sympathizes but turns her away because the agency's client list is full. Robin notices fingerprint bruising on Edie's neck, which Edie dismisses. Two weeks later, Edie is found murdered in Highgate Cemetery. Josh is found nearby, critically wounded but alive thanks to a thick leather jacket collar and a rare condition called situs inversus, which placed his heart on the opposite side from where the attacker struck. He is left partially paralyzed.

Allan Yeoman, Edie's agent, and Richard Elgar, head of Maverick Films, hire Strike and Robin to identify Anomie. Josh refuses to proceed with a pending film deal unless Anomie is found. Strike and Robin profile their quarry as likely young, with coding or artistic skills, extensive free time, and insider access to information about Edie and Josh. Robin devises a way into the game using login credentials obtained through Michelle "Midge" Greenstreet, one of the agency's subcontractors. Operating as "Buffypaws," Robin cultivates relationships with moderators. She also enrolls in a life-drawing class at North Grove Art Collective, a Highgate commune where Josh and Edie once lived, using the alias "Jessica Robins." There she meets Preston "Pez" Pierce, a digital artist; Nils de Jong, the eccentric Dutch millionaire who owns North Grove; and Zoe Haigh, a young woman who works at the collective. Robin notices a stained-glass window quoting Émile Durkheim on anomie, a sociological term for the breakdown of social norms, suggesting the origin of the troll's name.

Strike interviews key figures. Katya Upcott, Josh's surrogate mother figure, lives in Hampstead with her domineering husband Inigo, who has myalgic encephalomyelitis (ME), and their son Gus, a student at the Royal College of Music with a severe skin condition. Phillip Ormond, Edie's boyfriend and an ex-police computing teacher, gives contradictory information and reacts badly to questions about the bruising on Edie's neck. Kea Niven, Josh's ex-girlfriend, claims Edie plagiarized her ideas and has been secretly communicating with Inigo.

Charlotte Campbell, Strike's volatile ex-fiancée, visits the office and deliberately reveals Strike's relationship with Madeline to Robin, forcing Robin to confront her feelings. Strike, worried that Charlotte's estranged husband Jago Ross intends to name him in their divorce, assigns team members to investigate Ross. They obtain footage of Ross abusing his daughters, which Strike uses to keep his name out of the proceedings.

Strike discovers that two Halvening members, brothers Oliver and Charlie Peach, had infiltrated the game as LordDrek and Vilepechora. At Comic Con, Oliver is pushed in front of a train by an assailant in a Batman mask. Robin jumps onto the tracks to help rescue him, and her name is released to the media. Shortly after, a parcel bomb detonates at the office. Pat Chauncey, the office manager, slams the inner door shut just before the explosion, saving Strike's and Robin's lives.

Strike and Robin visit Josh in hospital. Josh reveals that the attacker whispered to him after the stabbing and shows them years of threatening private messages from Anomie demanding creative control of the cartoon. Through patient work, Robin identifies a teenage game moderator as Rachel Ledwell, the daughter of Edie's uncle Grant. Rachel provides the real name of Morehouse: Dr. Vikas Bhardwaj, a young astrophysicist who has cerebral palsy, based at Cambridge. When Strike and Robin arrive to speak with Vikas, they find him murdered, his throat slit and his hard drive missing.

Phillip Ormond is arrested after police discover he tracked Edie's phone to the cemetery but is released after explaining he found the phone dropped by the fleeing killer. Nineteen Halvening members are arrested. Under pressure from Strike, Yasmin Weatherhead, the moderator known as Hartella, reveals that Anomie has been blackmailing her into impersonating him in the game at specific times to create false alibis, meaning every suspect previously ruled out must be reconsidered. Robin discovers that four troll accounts coordinated with Anomie are all operated by one person, their handles referencing obscure composers and musicians. Strike pressures Grant Ledwell into producing a letter meant for Edie's coffin. Written in disturbed, obsessive handwriting unlike Katya's on the envelope, it vows to take control of The Ink Black Heart forever.

The musical references, the letter's content, and evidence pointing to someone within the Upcott household lead Strike to a devastating conclusion. When he calls Katya, her twelve-year-old daughter Flavia answers, screaming for help. Strike and Robin race to the house, where Gus Upcott is revealed as Anomie. He has killed his father, stabbed his mother, and is hunting Flavia with a machete. Strike is tasered and slashed at the front door, his lung punctured. Robin fights Gus through the dark house, activates her rape alarm, and barricades herself with Katya and Flavia in the bathroom. Neighbors, alerted by the alarm and a broken window, help subdue Gus after Robin strikes him from behind.

Strike recovers in hospital. Police find Josh's phone, the stolen dossier, latex masks, and the genuine letter Josh dictated for Edie hidden under a floorboard in Gus's room. Police also discover bugs Gus had planted in the house; recordings from them reveal that Inigo berated Gus for being exposed as a fraud at the Royal College of Music, triggering the final attack. Robin visits with news that the office door has been re-engraved to read "Strike and Ellacott Detective Agency," a change that moves her to tears. She tells Strike she has a date with DCI Ryan Murphy, one of the police investigators on the case. Trapped in his hospital bed, Strike finally confronts what he has spent years refusing to acknowledge: He is in love with Robin. He consoles himself that it is only one date.