A very difficult show to review, overall I'd give Series 1 an 8/10, a very good show, strong characters, intrigue etc, however something happens in the second series and has continued through to the present day, since that very first episode of Series 2 (or in fairness Part 6 of the opening Series) Line of Duty has become the best thing on the box. The cast work together in a way that you don't often see in many shows, the degree of realism each of them injects makes the show feel very real. Dunbar, Compston, McClure, Parkinson etc are all utterly phenomenal, I think though, it was the performance of Keeley Hawes as Lindsay Denton that increased my interest in the show, she was utterly amazing.
The transformation in the character of Steve Arnott has been intriguing, plaudits for Martin Compston, incredible actor, so diverse.
I suppose you could argue it's made in the style of the Scandinavian noir, but it goes deeper then that somehow, offering even more for the viewers. The series treats the viewer as if they have a degree of intelligence, it's deep and intricate without being too clever for its own good.
It comes as no surprise that the show's viewing figures have almost trebled, if you've not seen it, you have no idea what you're missing out on. 10/10
Bring on Series 5