Luke Mullen, sixteen year old son of a former, high-ranking police officer has disappeared, presumed kidnapped. While no-one quite dares to voice the fear that he could also be presumed dead, Detective Inspector Tom Thorne is brought in to beef up the squad dedicated to locating the missing boy. The first thing the team looks for is anyone with a grudge against Luke's father, a man who'd put a lot of tough villains away in his time. A list quickly emerges, but Thorne discovers that ex-DCI Tony Mullen has omitted the name of the most obvious suspect; a man who'd once threatened him and his family, and who, after serving time for his original crime, is now the main suspect in a murder which has been unsolved for four years. Is this a simple oversight - understandable considering the trauma of his son's disappearance? Or is it something more telling? Aware that he does not have the luxury of time, Thorne searches desperately for connections and leads, but learns that secrets are as easily buried as bodies, and that assumptions are the enemy of truth.