Falls the Shadow: Part 1

Falls the Shadow is the last of the four direct adaptations of Val McDermid's novels, and it takes its plot from The Last Temptation. Tony Hill is brought in to identify a serial murderer who is killing prostitutes and experimental psychologists in a particular sequence, and the police are treating the two sets of deaths as separate cases with separate offenders — which is exactly what the killer wants them to do.

The film's first achievement is making the audience share that mistake. The murders look unrelated because the victims have nothing in common and the methods differ, and it is Hill's reading of motive rather than method that reveals a single hand behind both. Guy Burt's convention of making the killers' reasons legible is applied here to a killer whose reasons are professional: the experimental psychologists are being killed for what they do, and the prostitutes for other reasons entirely, and the link between them is the case.

Then the episode does something the series had been building towards since 2004. Hill is arrested as a prime suspect, because he was the last person to see the first murdered psychologist alive and traces of his blood are found in her hotel room. Fielding provides him with an alibi and refuses to accept that he is a murderer, but another investigating officer, who believes in convicting on physical evidence alone, has him jailed. Hill's absence of motive is disregarded, and the killings continue while he is inside, which is what clears him.

Jailing the series' own investigator is the strongest statement of its central theme the show ever staged, and it works because the evidence against Hill is real. His blood was in the room. He had no alibi at the time. The judge of who is guilty here is not a fool but a man operating on a defensible principle, and the episode declines to make him a villain. Pip Torrens plays DI Brennan with a procedural flatness that is more effective than hostility would have been.

The episode is also the clearest expression of what the show believed about evidence and inference. Hill's innocence is established by the continuation of the killings rather than by his own testimony, which means the argument is settled by circumstance and not by reason. The film is honest about the fact that this is a lucky way to be exonerated.

It drew 5.03 million viewers, the lowest of the four two-parters' first halves, and is rated 7.9. Two limitations are worth noting. The alibi resolution is conventional after such a strong setup, and the second police officer's function — to represent conviction by physical evidence — is stated more than dramatised. The film's best quality is that it takes the series' long-standing tension between Hill and the institution and resolves it the only way it could: by putting him on the wrong side of a cell door.