California investigator Frank Bishop needs the help of imprisoned hacker Wyatt Gillette to catch a killer known online as Phate. Phate uses personal data and social engineering to enter victims' lives before murdering them, turning the connected world into a hunting ground. Gillette understands the methods but has secrets and enemies of his own. As the pursuit shifts between physical streets and hidden networks, the investigators must anticipate an adversary who treats murder like an immersive game.