These comments cover the whole two part story not just the concluding episode.
As this story opens a young worker at Billingsgate Fish Market is chases by other workers and left chained and covered in blood. His friend and his friend's father drive off in his car; shortly afterwards they are run off the road and his friend is shot. DCI Tony Underhill is convinced that the boy's uncle was involved as he has recently ended a prison sentence for a violent crime. This theory is somewhat undermined when DNA evidence shows that in reality he was the boy's father something he knew. When the boy's phone is analysed it points to another possible motive; he and his friend had apparently raped a girl, filmed it and posted the video on line a definite motive to kill him. It isn't long before his friend is shot and killed too. Strangely a DNA sample doesn't match with one taken at the first crime. Even more strangely there is a completely unrelated murder on the other side of London where the killer's DNA matches the sample taken at the second shooting that is known not to come from that killer.
To my mind this story was a step up from the previous one; it is also quite a bit darker. There are a decent number of suspects but interestingly either they didn't the opportunity or they motives are disproved. The ultimate resolution is a nice nod to a Hitchcock classic something that is clearly stated by Jack when he realises what happened. There are disturbing elements of the story; most notably when we learn that we learn that the shooting victims had committed a rape and the victim of that is driven to attempt suicide. The attacks are also quite brutal; especially when a man is stabbed to death. Thankfully this time the pathology team are just working to solve the case rather than getting caught up it an unfortunate cliché in too many episode. That is not to say there is no office politics; when Clarissa's husband helps recover data from a broken phone Tom worries that he will try to poach her. The ending is likely to split viewers' opinions as 'justice is served' outside the law I won't say more as details would spoil the end too much. Overall I'd say this was a really good story.
As this story opens a young worker at Billingsgate Fish Market is chases by other workers and left chained and covered in blood. His friend and his friend's father drive off in his car; shortly afterwards they are run off the road and his friend is shot. DCI Tony Underhill is convinced that the boy's uncle was involved as he has recently ended a prison sentence for a violent crime. This theory is somewhat undermined when DNA evidence shows that in reality he was the boy's father something he knew. When the boy's phone is analysed it points to another possible motive; he and his friend had apparently raped a girl, filmed it and posted the video on line a definite motive to kill him. It isn't long before his friend is shot and killed too. Strangely a DNA sample doesn't match with one taken at the first crime. Even more strangely there is a completely unrelated murder on the other side of London where the killer's DNA matches the sample taken at the second shooting that is known not to come from that killer.
To my mind this story was a step up from the previous one; it is also quite a bit darker. There are a decent number of suspects but interestingly either they didn't the opportunity or they motives are disproved. The ultimate resolution is a nice nod to a Hitchcock classic something that is clearly stated by Jack when he realises what happened. There are disturbing elements of the story; most notably when we learn that we learn that the shooting victims had committed a rape and the victim of that is driven to attempt suicide. The attacks are also quite brutal; especially when a man is stabbed to death. Thankfully this time the pathology team are just working to solve the case rather than getting caught up it an unfortunate cliché in too many episode. That is not to say there is no office politics; when Clarissa's husband helps recover data from a broken phone Tom worries that he will try to poach her. The ending is likely to split viewers' opinions as 'justice is served' outside the law I won't say more as details would spoil the end too much. Overall I'd say this was a really good story.