When a sex worker dies in suspicious circumstances in York, Detective Inspector Geraldine Steel struggles to remain focused on the murder investigation: she is distracted by her worries about her colleague and life partner, Ian Peterson, who has disappeared. As Geraldine becomes close to her new DS, Matthew, she is unaware that Ian is working undercover in London, trying to identify a criminal gang who have been targeting her. As a second victim is discovered in York, and Ian's life is threatened by a psychopath the tension mounts. If he fails in his mission, both he and Geraldine may die . . .