Young girls are disappearing around the country, and there is nothing to connect them to one another. Dr Tony Hill sets his team an exercise: they are given the details and asked to discover links between the cases.
Only one officer comes up with a theory that is ridiculed... until one of their own is murdered. For Tony Hill, the murder becomes a matter for personal revenge and joined by colleague Carol Jordan, he embarks a game where hunter and hunted can all too easily be reversed.