Line of Duty, trailers seasons 3 4

The third series follows Superintendent Ted Hastings (Adrian Dunbar), DS Steve Arnott (Martin Compston) and DC Kate Fleming (Vicky McClure) as they lead an investigation into the corrupt actions of Sergeant Danny Waldron (Daniel Mays). The fourth series follows Superintendent Ted Hastings (Adrian Dunbar), DS Steve Arnott (Martin Compston) and DS Kate Fleming (Vicky McClure) as they investigate the corrupt actions of DCI Roseanne Huntley (Thandie Newton).