When a series of vicious murders sends the town reeling, Tony becomes consumed with the notion that they are the work of killer William 'Mack the Knife' MacAdam. Newly-released back into society after being educated during his long sentence, MacAdam is now enrolled as a Ph.D. student in Tony's university class and seems overly keen to take his place as media pundit on serial killer cases. Tony's torment is worsened when he clashes with Carol over her desire to have a baby before it is too late. But could fertility be the key to solving the crimes? A husband and wife are brutally murdered in their beds. A woman is killed as she lies sleeping in the afternoon. A prostitute is discovered dead in the local canal. Worryingly for Tony, the killings bear the same MO as those of newly-released killer 'Mack the Knife' MacAdam, now reformed, re-educated and with a new identity - and enrolled as a PhD pupil in Tony's class. Investigations reveal a tangled web of personal relationships between the victims but none of it makes sense. Tony is tormented by the notion that Mack is the murderer, a belief strengthened by Mack's sardonic needling and his apparent desire to supplant Tony in the public eye. Meanwhile Carol has her own problems: her biological clock isn't so much ticking as ringing, and she needs to find someone to father a child. Her personal crisis causes friction with Tony - is she inviting him in or shutting him out? It dawns on Tony that the killer shares some of Carol's obsession with fertility. But the death of somebody close to Tony combined with Mack's renaissance as media pundit about the crimes spur Tony into a moral crisis. Can he and Carol achieve the self-knowledge required to solve this case?
Elenco: Robson Green , Mark Letheren , Mark Penfold , Simone Lahbib .