This is something a bit different from the usual police procedural and it works very well because of the stylish and stylised direction and some great acting. The different sides of policing are painted with a broad brush but are essentially true, from the squad-room boys' club to the top brassall management-speak plus old boys' network. Anyone who works in a company, private or public, of any scale, has seen these in action even today!
Phil Davis is cast very much to type as the cynical, angry, working policeman but the twist here is that he is the one who makes major mistakes every time about the perpetrator of the crimes and the possible suspects.
Steve Pemberton manages to be creepy and sympathetic at the same time.
Rupert Penry-Jones' subtle and far-from-heroic presentation of the "useless" plastic fast-tracker is spot-on, as is his gradual realisation that he's out of his depth and is being cast adrift by his "puppetmasters". He's been brilliant at the slow transformation into a real investigator, going with his instincts instead of by the book. It's a very unshowy but intense and believable performance and one of his best to date. The premise is highly imaginative by its nature but the mix of factual background and stylised dramatisation is so effective because it exercises the imagination. So many people, on the net and round the water-cooler, are talking about this drama, who dunnit and how the main characters are going to pan out, whether successful or failed or shattered. That's the mark of a really successful piece of TV!