As Luther's affection for Jenny grows, so does his determination to protect her and help her back on her feet. Baba, however, is determined to keep Luther on a tight leash. To add to Luther's difficulties, he is called in to investigate a man whose brutal and escalating murders seem to have no motive, leaving Jenny alone and vulnerable.

Luther's personal and professional life spirals out of control as he tries to cover up Toby's death and appease a suspicious Baba. He must also protect Jenny from any further harm. At work there's also a killer at large whose actions are ruled by his dice. How do you stop a man who sees life and death as a game and whose actions can't be predicted?