The fifth series of Line of Duty, consisting of six episodes, began broadcasting on 31 March 2019 on BBC One. The series follows the actions of Superintendent Ted Hastings (Adrian Dunbar), D.I. Kate Fleming (Vicky McClure) and D.S. Steve Arnott (Martin Compston) as they investigate an Organised Crime Group with links to missing undercover officer D.S. John Corbett (Stephen Graham). Anna Maxwell Martin stars in episodes five and six as D.C.S. Patricia Carmichael. Supporting characters include underboss Lisa McQueen (Rochenda Sandall) and the special counsel to the police and crime commissioner Gill Biggeloe (Polly Walker).