Fresh testimony launches AC-12 back on the trail of the Caddy, a corrupt officer with links to organized crime. But new disturbing evidence suggests the Caddy may reside within AC-12.
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 3, Episode 4 Synopsis and Schedule