In London 2011, an unnamed killer stalks “The Secretary” (Robin Ellacott) while gloating over his most recent murder. By killing Robin, he intends to avenge himself on Cormoran Strike, whom he blames for the loss of his son.

Robin thinks about the argument she and her fiancé, Matthew, had after meeting with Matthew’s friend Sarah Shadlock and her boyfriend. Over dinner, Sarah raised the topic of Robin’s colleague, Cormoran Strike, commenting on his status as a decorated war hero and describing him as particularly appealing. Afterward, Matthew accused Robin of talking relentlessly about Strike.

Robin goes to the private detective agency on Denmark Street, where she works. A courier wearing a motorcycle helmet hands her a package. Inside is a woman’s severed leg.

The woman’s right leg has been severed in precisely the place where Strike’s leg was amputated. An enclosed note quotes lyrics from the song “Mistress of the Salmon Salt” by the rock band Blue Öyster Cult. Strike notices that the package was initially addressed to him, but then Robin’s name was placed over his. Observing that there is old scarring on the dismembered limb, he is filled with dread.