DCS Kat Frank is back at the Future Policing Unit after a devastating loss - and straight into her most disturbing case yet. On Halloween night, a local MP is found murdered. Beside the body is a taunting message in binary code, aimed directly at Kat:Catch me if you can. The victim was a vocal opponent of AI. The motive looks political. But as Kat investigates with her partner, AIDE Lock - the world's first AI detective - the case spirals into something far more dangerous. Then a cyberattack takes down the National Grid. With the country in chaos and lives on the line, Kat and Lock must track a killer who is always one step ahead. But in a world of deepfakes, deception and digital ghosts, instinct is no longer enough. Kat must decide whether to trust the one thing she still fears most: her AI partner. Because this time, Lock may not just be solving the case. He may be changing what it means to be human. Can Kat stop a killer before the lights go out for good?