Line of Duty season six – air dates, cast, plot, trailer, H theories and what’s happened so far

Line of Duty season six - everything you need to know about the current series...

Line of Duty season six has brought AC-12’s finest – Ted Hastings (Adrian Dunbar), DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) back to our screens for a new case.

Written again by Jed Mercurio, season six also features Trainspotting and Harry Potter star Kelly Macdonald.

When does Line of Duty season six air

Line of Duty season six started on Sunday, March 21st and airs on Sunday nights on BBC One at 9pm.

There will be seven episodes in the new series, making it the longest series to date.

You can catch up on missed season 6 episodes on BBC iPlayer now as well as refresh your memory on seasons 1-5.

Line of Duty series six filming restarting

The cast and crew working on series six of Line of Duty (Picture: BBC)

What’s the plot?

Each of the first five series of Line of Duty sees the story revolving around one central character the team are investigating. As fans will already know, the pivotal character this time is DCI Joanne Davidson, played by Kelly Macdonald. She heads up the Murder Investigations Team (MIT) at Hillside Lane station, who are conducting an investigation into the murder of Gail Vella.

AC-12 are also trying to work out who’s behind the murder, and whether Jo is involved. MIT is currently trying to pin Gail’s murder on Terry Boyle, a character who we know has been used by the OCG several times already. This is the most explosive season yet, but we should expect even more action from the last few episodes!

Will Jo be behind her murder after all? Is she truly a bent copper? We still can’t be sure…

What happened in season 6, episode one?

Warning – spoilers for the first episode below

Probably the biggest shock in the opening episode of season 6 was the fact Kate is no longer on the AC-12 team. She is now working directly under newcomer DCI Jo Davidson as they try to crack the murder case of journalist Gail Vella.

We have also learned that Steve isn’t happy with his role on AC-12 and is looking to try something new within the police force… plus he also seems to be battling a painkiller addiction judging by his stash of tablets at home.

Joanne Davidson seems to be hiding some serious skeletons in her closet, not only is she now under suspicion after a questionable decision to reroute the Terry Boyle arrest by suggesting they investigate an armed robbery, but she was also in a doomed relationship with fellow police officer, Farida Jatri.

The CHIS (Covert Human Intelligence Sources to you and me!) who gave the name Ross Turner to the police is also dead, but did he jump or was he pushed? Did DCI Davidson have something to do with his death?

And Terry Boyle from seasons 1 and 5 is also back, this time under suspicion for killing Gail Vella. But what is his connection to the OCG these days? And where has his fridge freezer gone?!

What happened in episode two?

If you’re not caught up, don’t read on!

In episode two, Ted finally authorises AC-12 to start investigating MIT. Scared for her life, Farida requests a transfer to another police department, away from Jo.

Meanwhile, Steve finds out that Gail Vella might have uncovered something crucial to exposing police corruption, but her back-ups have been stolen!

The Hill is rocked by the news that Carl Banks has been found dead at an abandoned site. A new officer, Ryan Pilkington, finds a knife at the scene that ties Alistair Oldroyd, aka “the CHIS”, to the murder. Kate seems sure that she recognises him from somewhere.

Steve informs Kate that AC-12 are moving ahead with their investigation, and she betrays his trust by revealing this to Jo. This allows her to prepare for their arrival and withhold evidence due to her “concerns” about info being leaked to the OCG.

This doesn’t stop AC-12 though, and they turn up again later on to start seizing computers and files relating to Operation Lighthouse. Whilst there, they even serve a very smug Jo with a Regulation-15 notice for gross misconduct!

Ted, Steve and Chloe grill Jo in a tense interview, where she throws suspicion at Farida, urging them to search Farida’s home just before AC-12 place Jo under arrest. A forensic team then uncovers a stash of burner phones hidden in Farida’s home, leading to Farida’s arrest and forcing AC-12 to let Jo go free once more.

Ryan is waiting to drive her home, but he takes her to a shady underpass. There, she receives a parcel containing yet another mobile phone, proving once and for all that she’s a bent copper after all!

What about episode 3? What’s Jo up to?!

MASSIVE spoilers ahead!!

Episode three finally saw Kate working more closely with AC-12 once again!

At the start of the episode, DS Chris Lomax informs Jo that he’s found a new witness who saws she saw Terry Boyle arguing with the CHIS, Alistair Oldroyd. Terry is brought back to the Hill and interviewed once again. Just as Terry’s about to reveal some new info, Jo ends the interview out of concern for Terry’s mental wellbeing.

Ryan joins Terry as he is escorted home, reminding him he’s still his “best mate”. Ryan tells the driver, PC Lisa Patel, the route has changed, directing her to drive by a reservoir. Out of nowhere, he attempts to strangle her, sending the car into the water! Against all odds, Lisa, Terry and Ryan survive, so Ryan returns to the reservoir and drowns Lisa in the water. Luckily, Kate had spotted the car change course and followed it to the water, arriving just in time to stop Ryan from killing Terry, too.

Steve finally reveals Ryan’s true identity to Kate. He’s also scared by the sudden arrival of AC-9 officers who have been asked to attend and conduct routine drugs tests of AC-12 officers. Ted told them Steve wasn’t available, but he clearly knows Steve is in a bad place…

Steve goes to confront Steph Corbett now he knows Steph told Ted about his drug addiction (although he later spends the night with her!). Meanwhile, Ted is told to end the search for H by DCC Andrea Wise!

Back at the Hill, Kate interviews Ryan, fully aware he must be working with the OCG. Farida refuses to give AC-12 a second interview after her wrist is broken by a prison guard.

Later on, Jo confides to Kate that she believes DSU Ian Buckells is the one leaking info to the OCG, and the missing Gail Vella documents turn up in the boot of his service vehicle, and he is brought into AC-12 for questioning. At the end of the episode, Jo tells a mystery contact that it’s “all okay” with Buckells as her scapegoat.

What happened in episode 4?

HUGE spoilers ahead for episode 4!

Jo Davidson is made a temporary SIO after Buckells’ arrest. Ted and Kate meet to discuss what to do about Ryan Pilkington at the underpass, but Kate suggests just placing him under surveillance to avoid alerting him.

Steve, Chloe and Ted interview Ian Buckells about his role in Operation Lighthouse. Steve believes Buckells is too incompetent to be working for the OCG, but Kate believes this is just his cover. Meanwhile, Ted is informed by DCC Andrea Wise that he’s no longer able to lead his department and encouraged to “retire”.  AC-12 will be merged with AC-3 and AC-9 into a brand new unit, with a new commanding officer. 

Elsewhere, Jo attempts to distance herself from the OCG and tries to transfer Ryan to a different department. Kate’s surveillance reveals Ryan has been stalking and watching Jo, and he intimidates her into keeping him at Hillside Lane to continue working for the OCG. 

Later on, Steve identifies Jimmy Lakewell’s voice from one of Gail Vella’s unreleased podcast files. Steve arranges an offer of immunity and witness protection in exchange for new information on the OCG. Later, officers attempt to remove Jimmy from HMP Blackthorn, but the OCG ambush the police convoy en route, leading to an incredibly tense shoot out!

Buckells is sent to Blackthorn, and Lee Banks uses him to distract Jimmy just long enough to so he can murder Jimmy for being a “rat”. DNA traces at Farida Jatri’s home suggest Jo may have planted the burner frames to frame her. The same traces are also checked against officer data, and they reveal she is related to someone who already appears in police databases… but who could it be?!

Will we find out who H is in season six of Line of Duty?

Well, we know – or think we know – that H isn’t one officer but a group of four corrupt officers.

Three of them have been exposed – but during his dying declaration corrupt officer DI Cottan signalled via morse code that there are four “Hs”.

So far, the names that have been identified are Cottan himself, Derek Hilton and Senior Legal Counsel Gill Biggeloe, leaving one name that we are still yet to discover.

See our guide Who is H in Line of Duty? for all our theories!

Who’s in the cast?

Line of Duty season 6 take one

The very first take of the new series (Picture: BBC)

Alongside the regular cast and Kelly Macdonald, newcomers Shalom Brune-Franklin (Our Girl), Perry Fitzpatrick (Downton Abbey), Andi Osho (I May Destroy You) and Prasanna Puwanarajah (Doctor Foster) have also joined the series.

Shalom Brune-Franklin plays DC Chloe Bishop, a new AC-12 recruit who has been brought in to help crack down on Davidson.

Line of Duty season six lead cast

Kelly Macdonald plays a key part in the new series (Picture: BBC)

Who is Gail Vella?

Gail Vella Line of Duty

Gail Vella is the series six murder victim (Picture: BBC)

Gail Vella is an investigative TV journalist who was shot dead outside her house in the Kingsgate area on 10th September 2019 at point blank range.

It has been suggested by the investigating team that she was either the target of a contract killing, or that she was murdered in cold blood by a crazed fan or stalker.

Gail’s high-profile and yet unsolved murder is now being worked on under the investigation name Operation Lighthouse, which is being led by newcomer DCI Joanne Davidson and has none other than a certain Kate Fleming on the team.

Is there a trailer?

Yes – and it’s a good one!

What else do we know?

Series six is filmed in Belfast and production was forced to be shut down due to the pandemic last spring.

Thankfully the team worked against the odds and got the rest of the series filmed after lockdown one restrictions eased.

Line of Duty series 6 airs on Sundays at 9pm on BBC One – see our TV guide for more shows to enjoy. You can catch up on series 1-5 on BBC iPlayer now.

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