The Ink Black Heart (Cormoran Strike # 6)

When frantic, dishevelled Edie Ledwell appears in the office begging to speak to her, private detective Robin Ellacott doesn't know quite what to make of the situation. The co-creator of a popular cartoon, The Ink Black Heart, Edie is being persecuted by a mysterious online figure who goes by the pseudonym of Anomie. Edie is desperate to uncover Anomie's true identity.

Robin decides that the agency can't help with this - and thinks nothing more of it until a few days later, when she reads the shocking news that Edie has been tasered and then murdered in Highgate Cemetery, the location of The Ink Black Heart.