In Falls the Shadow, the second episode in series six of this compelling drama series, forensic clinical psychologist Dr Tony Hill (Robson Green) is brought in by Inspector Alex Fielding (Simone Lahbib) to uncover the identity of a serial murderer wh... (more)o is killing prostitutes and experimental psychologists in a very specific sequence. At first it looks as if the murders are unrelated - committed by two different serial killers - and the police are treating the murders of the prostitutes and psychologists as separate cases. But as the investigations unfold, Tony begins to see parallels between the motivations of both sets of murders, and using his understanding of the criminal mind, he reveals that it is in fact the same killer perpetrating both. Matters are complicated when Tony is arrested as a prime suspect in the case because of his friendship with the first murdered psychologist. He was the last to see her alive and traces of his blood are found in her hotel room. So did Tony really kill her, or is he telling the truth? Although Inspector Fielding comes to Tony's rescue, providing him with an alibi and refusing to accept that he is a murderer, another police inspector who believes in convicting purely on the basis of physical evidence has Tony thrown into jail. The fact that Tony has no motive for murdering his friend is disregarded. But when the killings continue while Tony is behind bars, it becomes clear that he can't be the murderer after all. So who is murdering prostitutes and experimental psychologists? Tony's psychological insights finally lead Inspector Fielding and the team to the murderer, but when Tony insists on confronting the murderer himself, he gets more than he bargained for. Will this be the end of Tony Hill?