Play Hard

Ok, so here’s everything we know about Line Of Duty so far…

Written by Becky Hardy
Published 10.03.2021

By Becky Hardy

Yes, Boris has now announced the roadmap out of this lockdown and yes, of course we’re very excited about the potential developments of the next few months. But there’s one date that stands out more than any other, and it doesn’t have anything to do with COVID. Sunday 21st March – the return of Line Of Duty.

If you’ve seen any of the BBC’s hit cop series and it isn’t your favourite show ever then, we’re sorry, you’re probably lying. All five series have been a smash hit with audiences so far, with the finale of series five the most-watched programme of 2019 (by a landslide). So we almost heard the collective intake of breath across the country when, at long last, the new trailer for series six dropped at the start of March.

But while we’ll not hear anything negative about the escapades of the wholly (bad-ass) trinity – aka Superintendent Ted Hastings (Adrian Dunbar), DS Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) – we will concede one point: there’s a lot to remember.

Luckily for you, we’ve racked our brains and – for the good of our readership, guys – have rewatched series one–five, just so we can provide this handy refresher for those of you who may have forgotten some of the finer details.



That we will, of course, be meeting a new guest star and chief suspect. In series six, this comes in the form of Trainspotting, Harry Potter and Broadwalk Empire alumni, Kelly Macdonald. She’s set to play DCI Joanne Davidson, who show creator Jed Mercurio has described as being ‘the most enigmatic adversary AC-12 have ever faced’. #chills

The new series of the show is set a year and a half on from the events of the series five finale, (we’ll cover that again in a sec), and features a brand new case for AC-12.

Best of all, the new instalment of Line Of Duty will feature an extra episode – taking the series up to seven episodes, instead of the usual six.

Ok, back to where it all began now…



‘You take a shot at the king, make sure you kill him, son!’

Cast your mind back to 2012. A young, fresh-faced and idealistic DS Arnott refuses to  participate in a police cover-up. Although his actions cost him his popularity in the force, they do help him get a job – he’s recruited by our main man, Superintendent Ted Hastings, head of anti-corruption unit AC-12.

DS Arnott’s first assignment is to investigate DCI Tony Gates – a high-flying officer with a suspiciously impressive success rate. With the help of undercover officer DI Fleming, Arnott discovers Tony has indeed been covering up for a deadly hit-and-run.

Realising his career is over, Tony takes his own life – but the corruption does not die with him.

Another officer in his team, DS Matthew ‘Dot’ Cottan, is revealed to be an inside man for gangster John ‘Tommy’ Hunter. But Dot – also known as ‘The Caddy’ (#important) – is better than Tony at covering his tracks…


‘People have underestimated me my whole life.’

Series Two opens with a police convoy ambushed by two gunmen, who leave three officers dead and their prisoner hospitalised. The prisoner (who is later killed) is revealed to be none other than Tommy Hunter, who had been under witness protection.

Enter Keeley Hawes (to a chorus of ‘boo’s). DI Lindsay Denton (Hawes), who had been in charge of the convoy, comes under suspicion from AC-12, and narrowly survives a murder attempt.

It’s later revealed that she’s a pawn in a plan cooked up by Cottan and his criminal associates, who wanted Tommy silenced in order to protect Dot’s secret identity.

Although Denton didn’t know exactly what she was doing, she’s convicted of conspiracy to commit murder and handed a life sentence.

The series ends with Cottan newly installed at AC-12, safely hiding in plain sight…


‘We gather evidence and the people decide. They’ve decided she didn’t do it because you couldn’t keep it in your pants!’

A police raid ends with Sergeant Danny Waldron gunning down a suspect in cold blood, then making it look as if the dead man shot first.

Danny is then killed himself, but not before alerting DI Fleming to the existence of a list of people involved in a child abuse ring. #HIGHLYIMPORTANT.

Finding the list and seeing Tommy Hunter’s name on it, Dot Cottan – still ‘working’ for AC-12 – destroys it. Oh, he’s also making it look as if Steve is the mysterious ‘Caddy’.

While appealing her imprisonment, DI Denton reveals she had sex with Arnott while he was undercover (#FFSSteve), thus exposing AC-12’s failings in their investigation.




Determined to make her way back into the force after her release from prison, Denton agrees to assist Arnott on AC-12’s latest case. She does that and more, finally discovering the truth about Cottan. She dies at his hand – but not before finding the mysterious list and sending it to AC-12.

But with the evidence now stacked against him thanks to Cottan’s cunning work, Arnott is arrested for Denton’s murder and on suspicion of being The Caddy.

Luckily for everyone, DI Flemming reveals she’s actually been undercover investigating her own department this whole time – under the instruction of AC-3 (#plottwist). She turns the tables on Cottan and, after questioning, he eventually unmasks himself as The Caddy.

Cottan escapes – only to die, semi-heroically, while stopping Fleming being shot by one of his associates.

The series ends with Steve returning to duty, the chief abuser being convicted and Kate receiving both a commendation and a promotion (cue #officetension).



‘This is beginning to feel like a life’s work!’

Under pressure to catch a serial killer, DCI Roz Huntley (Thandie Newton) could do without forensic coordinator Tim Ifield questioning the evidence against the suspect.

He takes his concerns to AC-12 and DS Fleming goes undercover to investigate Huntley. Suspecting Ifield has shopped her, Huntley confronts him at his home.

Huntley returns to work with a concealed hand injury. Ifield is then discovered dead, with three fingers amputated.

Taking charge of the crime scene, Huntley implicates Ifield in another murder. Her husband Nick refuses to confirm her alibi and falls under suspicion himself. When DS Arnott goes to Nick’s office to question him, a man in a balaclava throws him down a flight of stairs (#JusticeForSteve).

Huntley has to have her hand amputated and is arrested for killing Tim Ifield. Her solicitor is found to be linked to ‘Balaclava Man’ – who we find out is Huntley’s boss, Assistant Chief Constable Derek Hilton. Hilton makes a run for it, but can’t escape the #balaclavagang, who silence their one-time asset in an apparent suicide.

THE MOST IMPORTANT BIT OF INFO YET – a recording of Cottan’s deathbed declaration reveals he was promoted by a corrupt copper whose name begins with ‘H’. Is this the newly deceased Hilton… Or could it be Ted Hastings?!


‘I’m just trying to get to the truth. The top brass, they don’t want me to succeed.’

When a police convoy is hijacked by an organised crime group (OCG), AC-12 suspect undercover police are involved.

They’re right. The raid was masterminded by DS John Corbett (Stephen Graham), who has been posing as a criminal in order to identify the mysterious H. But before Corbett can unmask H, he is betrayed by second-in-command Lisa McQueen and brutally murdered.

The ensuing fall-out sees Ted Hastings suspended, investigated and charged with conspiracy by DCS Patricia Carmichael (#smarmy).

During a tense interrogation, Hastings turns the tables by exposing lawyer Gill Biggeloe as part of the OCG.

The series ends with Hastings back in charge at AC-12, McQueen given immunity and, most importantly, young Ryan Pilkington – Corbett’s killer – inducted as a student police officer. And the cycle continues…




The balaclava gang are behind pretty much every crime we’ve seen in Line of Duty. Believed to all be involved with the child abuse ring partially uncovered in Series 3, they work in conjunction with ‘H’ – a shady figure embedded within the upper echelons of the police force.

But the question remains – who is H?


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