Line of Duty series 6: Your guide to who's in it, when it's back and what to expect

Will this be the last time we see AC-12 in action? Who is lined up to star in the sixth series? And with filming halted for lockdown, when will Line of Duty be back on our screens?

By Sophia Moir Published: 10 December 2020 - 3.26pm
BBC One Vicky McClure, Martin Compston and Adrian Dunbar in the Line of Duty

If you’re hooked on Line of Duty, you’ll be thrilled to know that a sixth season is on its way.

Filming on season 6 has finished - after a hectic year of filming with social distancing restrictions and lockdowns - and the new episodes will arrive in early 2021 on BBC One.

The hit British police drama was re-commissioned for a fifth and sixth season at the end of season four back in 2017.

BBC director-general Tony Hall said at the time: “I am very excited to say there’s not one but two more series of Line of Duty. So hooray for AC-12!"

Line of Duty is the UK's most-watched show of 2019 to date, with 7.8 million viewers tuning in to watch the drama of the series 5 premiere unfold.

Here’s everything we know about Line of Duty season 6 on BBC One so far, including whether the anti-corruption squad will continue after that...

***SPOILERS for series 1-5 ahead***

When is Line of Duty series 6 released?

Martin Compston, Vicky McClure and Adrian Dunbar on the set of Line of Duty Vicky McClure/Instagram

The BBC has confirmed that the series will air in early 2021 and it is expected to premiere in either February or March.

The show's creator and writer Jed Mercurio confirmed filming had ended at the end of November and a new picture from the show was released to mark the occasion.

The image features Kelly Macdonald (Trainspotting, Boardwalk Empire), who joins the show as Detective Chief Inspector Joanne Davidson, the senior investigating officer on an unsolved murder case whose unconventional conduct attracts the attention of AC-12.

Kelly Macdonald on the set of Line of Duty BBC

Line of Duty showrunner Jed Mercurio said: "Thanks so much to our brilliant cast and crew who applied rigorous Covid safety measures to deliver Line of Duty six to our wonderful fans. We’re all immensely grateful to World Productions and the BBC for the unswerving support they’ve given us in a time of unprecedented challenges to UK television production."

Filming for series 6 began in February 2020, in Belfast, Northern Ireland, as Compston and Mercurio both confirmed on social media at the time, below.

It was scheduled to last until May 2020, but the UK went into lockdown in March 2020 and filming on the show was suspended after just four weeks.

The BBC and Jed Mercurio confirmed that filming had re-started in September 2020 - some six months after it was abrubtly cut short - albeit with social distancing measures in place.

Posting a picture of crew members and Martin Compston wearing face masks, Mercurio thanked the "dedicated cast and crew for keeping the #LineofDuty filming CoViD safe".

Simon Heath, Executive Producer for World Productions, confirmed that the show has implemented "all the industry Covid protocols", and filming is in accordance with current government guidelines on COVID-19.

It's not known whether the four weeks of footage the crew did manage to film in Belfast before lockdown will be able to be used, or whether they're filming again from scratch.

Speaking on The Andrew Marr Show, Mercurio said: “We’re all considering [a rewrite]. We shot for four weeks in a pre-lockdown world, and all that material would have to be reshot if we were going to change things.

“That would have huge cost implications, but we are considering it.”

In October 2019, before filming was suspended, Mercurio was asked about the series 6 air date by, and responded: “I would hope it’s sometime in 2020, next year. But that’s not something that we’re able to confirm.”

All five previous seasons - except for series 1 - have consisted of six one-hour episodes on BBC One, so we reckon series 6 will be the same.

Fingers crossed for another 90-minute finale episode too, especially if it’s the last ever episode - more on that later.

Who’s in the cast?

It's been confirmed that the three main three cast members are returning for series 6. That’s Vicky McClure (DI Kate Fleming), Martin Compston (DS Steve Arnott) and Adrian Dunbar (Superintendent Ted Hastings)

First look at Kelly Macdonald in Line of Duty BBC
Kelly Macdonald joins the cast of Line of Duty

However whether they’ll survive for the whole series remains to be seen, as the show’s creator and writer Jed Mercurio has a habit of killing off the show’s main characters.

As for the rest of the cast, we’ll update this article with more information when we have it - although we'd be amazed if Anna Maxwell Martin wasn't back to show us more about who Detective Chief Superintendent Patricia Carmichael really is.

In November 2019, it was confirmed that Kelly Macdonald will star as guest lead in the next series of the show.

She will play Detective Chief Inspector Joanne Davidson, the senior investigating officer of an unsolved murder, whose unconventional conduct raises suspicions at AC-12.

“DCI Joanne Davidson [Kelly Macdonald] will prove the most enigmatic adversary AC-12 have ever faced”
- Jed Mercurio

Macdonald is best known for her roles in Trainspotting, Gosford Park, State Of Play, No Country For Old Men, Boardwalk Empire and, most recently, The Victim and Giri/Haji. 

Line of Duty writer and showrunner, Jed Mercurio, says: "We're honoured that Kelly Macdonald will join Martin, Vicky and Adrian in series six of Line Of Duty. DCI Joanne Davidson will prove the most enigmatic adversary AC-12 have ever faced."

Line Of Duty newcomers Shalom Brune-Franklin, Perry Fitzpatrick, Andi Osho and Prasanna Puwanarajah will also join the show for series 6.

One actor who'd be up for appearing in the show is British actor Nicholas Pinnock, who's appeared in crime dramas including Marcella and Criminal.

Asked by whether he'd be up for appearing in Line of Duty - whose lengthy interrogation scenes are very similar to the episodes of Criminal - Pinnock told us: "Oh absolutely, yeah! I’ve been watching it since the very first series came out. I think I’ve only missed one season, which is the latest one, so I’ll definitely, definitely catch up.

"If the right part came along and I was available to do it, it’s definitely a franchise I’d consider doing, considering my lack of not wanting to do much television anymore. We’ll see, but I wouldn’t flatly turn it down, let’s put it that’s way! It’s a great show."

What will happen in series 6?

Season 5 of Line of Duty was set up around answering one of telly’s most burning questions: Who is the corrupt police officer, known as H?

By the finale, we'd discovered that H was not one person, but was actually made up of four Caddies, signalled by original Caddy DI Matthew "Dot" Cottan who the team noticed had been tapping out the Morse Code for H - four dots - in his dying declaration.

We know that ACC Derek Hilton was the second, and series 5 named legal counsel Gill Biggeloe as the third, so we're expecting to see AC-12 searching for the fourth and final corrupt official in series 6.

Hastings is still a strong possibility despite being framed by Biggeloe in series 5, and AC-3's DCS Patricia Carmichael who was investigating him also looks decidedly dodgy.

Meanwhile, OCG member Ryan's success in getting into police college will surely be followed up as he becomes the force's newest corrupt officer.

There are still many loose ends to be tied up, and it’s believed that Jed Mercurio - below right with the cast - already knows what’s going to happen in series 6.

Speaking to journalists including to promote the fifth series, Martin Compston hinted that storylines would be further developed - and potentially come to a conclusion - in series 6.

He says: “The BBC have been really good to us. Ever since series 2, we’ve been commissioned for two at a time... because Jed has been very adamant that he’s going to be the one that finishes it, so if he doesn’t know if we’ll get a series 7 or 8, then he will [finish it]. 

“His thing is he has to give the pay-off to the audience, who have stuck with us all these years. It gives him the breathing space to go ‘I can develop this over next series, because I know we’re going to be there’, so that’s been great.”

Adrian Dunbar, who’s played the gaffer alongside Compston for five seasons, agrees that Mercurio knows what’s going to happen in the story beyond what's been on TV.

He tells us: “I think he does [know where it’s going to go]. He’s mapped it out roughly. I think initially he had mapped out roughly up to series 5, but then I suppose, because it took off the way it did, he’s thought beyond that now, and he’s still thinking beyond that.

“But he’s still managing to hold onto our initial audience, and give them all these pay-offs of sticking with the original arc. The original arc still keeps going.”

The full plot for season 6 has not yet been announced, but we'll update this article with more information when we have it.

Will there be a series 7?

Adrian Dunbar as Ted Hastings in BBC's Line of Duty

“We recognise that Line of Duty has a life span.... I have some thoughts about how the show is going to end”
- Jed Mercurio

Line of Duty has only been commissioned up to season 6, with its creator Jed Mercurio telling journalists that the show has ‘a life span’. Does this mean that the next series will be its last?

Asked how long Line of Duty can go on for, Mercurio said at a press screening for the show: “I don’t know. We all love making the show. I think a lot depends on how people respond to it.

“I think that it’s great that people get very excited about it, when they get to the end of the series and they talk about what they want to know, and what they want to see next.

“But I think we recognise that it’s got a life span, so I think we’ve got to calibrate that against the audience responses.

“I have some thoughts [about how it’s all going to end].”

Is there a trailer?

There isn’t currently a trailer for season 6, as the series has not been filmed yet so there is no footage. That doesn’t mean you can’t get excited for the new season though - there’s plenty of time to go back and re-watch series 1-5 of Line of Duty.

Watch Line of Duty if you liked…

Bodyguard (below), Save Me, Undercover, Luther, Marcella, Unforgotten.

Richard Madden in BBC's Bodyguard

Catch up on all five seasons of Line of Duty on BBC iPlayer.