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Line of Duty recap: what you need to know ahead of series three

Need a reminder of where we left AC-12 at the end of series two? Here's a quick round-up of all the intelligence we have (series one and two spoilers, obviously)

Published: Thursday, 27th July 2017 at 1:00 pm

Keeley Hawes's DI Denton may be behind bars, but don't assume that means a completely fresh start for Line of Duty series three.


Each series of the police thriller has stood on its own, but there is one thread that weaves the whole thing together: DS Matthew 'Dot' Cottan. And he's not going away in series three.

So, here's a very quick recap of the key parts of Line of Duty series one and two that will help set up the latest run of Jed Mercurio's mercurial thriller.

First, the team: Martin Compston plays DS Steve Arnott, a former firearms officer who, after a botched operation, told the truth rather than lie to protect his fellow officers. This grabbed the attention of anti corruption unit AC-12 and Superintendent Ted Hastings, who saw value in Arnott's honesty.


One of Arnott's first cases was an operation against high-flying (and highly strung) copper Tony Gates (Lennie James). Working with Arnott was undercover police officer DC Kate Fleming (Vicky McClure), who sacrificed friends and family for her duplicitous life.


DS Matthew ‘Dot’ Cottan (Craig Parkinson) was a fellow police officer in Gates's disgraced unit. But rather than falling with his commander, he rose again, winning the trust of Ted Hastings after testifying against Gates.


However, it quickly becomes clear that Dot wasn’t just a good man in a rotten unit. At the end of series one, he is revealed as the inside man for local crime boss Tommy. Dot’s codename is ‘The Caddy’, after he made his criminal connection while working at a golf club.

At the end of series one, we learn that crime boss Tommy has been placed in witness protection. So we should probably have realised that the attack on a police convoy at the start of series two involved lovely Tommy and his 'Caddy' friend.

Part-way through series two, Tommy is revealed as the witness killed in the police ambush. DI Denton (Keeley Hawes) is the only one left alive from the attack and is immediately placed under suspicion.


The truth is, Dot arranged the hit, in order to protect his secret identity. Denton, who was part of the plan but never knew the identity of the mastermind behind it, takes the fall and is imprisoned for life.

AC-12 try to discover the identity of ‘The Caddy’, but as Dot is part of the investigation, he is able to pin another cop as the dodgy one, with the help of his former colleague Nigel Morton (Neil Morrissey).


It’s enough to give Dot a permanent position with AC-12: the most corrupt cop of the lot is now an anti-corruption officer himself.


Will Nigel’s knowledge eventually bring Dot down? Or now he’s covered his tracks, will Dot become an upstanding officer? And how will it impact AC-12's ability to investigate their new prime target, Daniel Mays' Sergeant Danny Waldron?


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