The Cuckoos Calling

by J. K. Rowling

Disabled Afghan War veteran and struggling private investigator Cormoran Strike is approached by John Bristow, the adoptive brother of Strike's childhood schoolmate Charlie. Bristow believes his supermodel sister Lula Landry, whom his parents adopted after Charlie died, did not jump to her death three months earlier and wants Strike to investigate further. Although initially unconvinced, Strike takes on the case due to his need for money. As the investigation commences, Strike meets Robin Ellacott, who has been assigned by a temp agency to act as his secretary, and hires her for a week despite his lack of funds. Robin, who has just become engaged to longtime boyfriend Matthew, turns out to be much more competent than Strike expected, prompting him to extend her stay.

The two set about interviewing Lula's friends and family members as well as her personal driver, the doorman at her Mayfair flat and a fashion designer who affectionately called her "Cuckoo". With each recollection of Lula, Strike gradually suspects the circumstances of her death are murkier than he initially imagined. His suspicions are confirmed after interviewing Lula's downstairs neighbor Tansy Bestigui, who told police that she heard Lula fighting with a man shortly before her death. Strike, who originally dismissed Tansy's statement because it was clear she could not have heard the fight through her flat's triple glazed windows, concludes that part of her story was true. While she did hear an argument and see Lula fall to her death, Tansy did not inform the police she was standing outside when the fight occurred. Tansy reveals she had been kicked out by her husband following a heated argument over her cocaine use and, after telling him that she saw, had been threatened into changing her story.

Shortly afterward, Lula's friend Rochelle is found dead hours after leaving a meeting with Strike. He becomes convinced that she was in contact with the killer and later deduces that Lula, who took an interest in investigating her biological roots before her death, was murdered for the ten million pounds she stood to inherit upon her adoptive mother's death. Strike later meets with Bristow in his office, revealing that he is responsible for killing Lula and Rochelle as well as Charlie, who everyone believed died after riding his bicycle into a quarry. Bristow was both enraged that Lula had tracked down her biological brother, Jonah, and jealous of her success. He murdered her for the same reason he murdered Charlie, which was to secure his own position, and then used Strike in an attempt to frame Jonah for the crime. Strike goes on to explain that Lula made a will that left her estate to Jonah and cut the Bristow family out entirely, which Bristow suspected. Bristow organized a plan to frame Jonah, which would make him unable to inherit, and used Strike's friendship with Charlie to achieve his endgame. Realizing he has been caught, Bristow tries to stab Strike only to be subdued after Robin enters the office.

Sometime later, Robin is preparing to leave for a supposedly permanent job when Strike gives her a parting gift in the form of a dress she tried on during the investigation. Despite being unable to pay her and being unable to suppress his romantic feelings for her, Strike convinces her to stay on.