When Edie Ledwell, the cocreator of the popular cartoon The Ink Black Heart, is found murdered only a few days after begging private detective Robin Ellacott for help in tracking down a mysterious online figure known only as Anomie who was persecuting her, Robin and Cormoran Strike are drawn into the quest to uncover the true identity of Anomie, a case that threatens them in horrifying ways.

An elite gamer who uses her status to secure sponsorships to help her struggling family and a fellow player who resists his mom's ambitions for his future find their virtual worlds and blossoming romance challenged by malicious trolls.