The thrilling third series introduces Sergeant Danny Waldron (Daniel Mays), the highly proficient leader of a police Armed Response Unit whose unpredictable behaviour is becoming a threat to colleagues and suspects alike. When AC12 are called in, DS Steve Arnott (Martin Compston) clashes with Danny, and it's left to DC Kate Fleming (Vicky McClure) to investigate undercover. As the inquiry intensifies, Supt. Ted Hastings (Adrian Dunbar) begins to suspect the case is linked to AC12's past and a possible traitor in their midst.
Third series is seldom promising but the writing is a little more believable and some shaky acting notable by Martin Compston is thrown off. The plot remains the weak part of this crime drama, the camera work has improved and the new parts of the cast bring the acting level up to pretty impressive. There seem to be quite a lot of crime dramas at the moment but this is worth a watch as being very dramatic.