With time running out, AC-12 attempt to unmask 'H', the Fourth Man (or Woman) commanding the network of corrupt officers behind the hug of Gail Vella. But sinister and powerful forces appear intent on orchestrating a cover-up.
Steve Arnott is a young officer who's fallen foul of his superiors for refusing to help in the cover-up of an operation that ended in the shooting of an innocent father. He seems ideal to join AC-12, an anti-corruption police unit, just as it starts to investigate Detective Chief Inspector Tony Gates, the regional force's Officer of the Year.
Line of Duty - Series 6, Episode 7 Synopsis and Schedule