Line Of Duty season 6: 13 brilliant fan theories that could explain everything

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Don’t even think about calling yourself a Line Of Duty fan until you’ve read through these compelling fan theories… 

Updated on 12 April: If you’re anything like Gogglebox’s Jenny Newby, then you’ve no doubt been conducting your own Line Of Duty investigation ever since the season six premiere on 21 March.

Now, though, we’re almost halfway through the BBC crime series, and the notes in our trusty notepads are getting a little… well, a little muddled. There are just too many questions we want answered; is Jo Davidson (Kelly Macdonald) truly a bent copper? Who’s pulling the strings of twisted police officer Ryan Pilkington (Gregory Piper)? Is DS Ian Buckells (Nigel Boyle) as nefarious as Jed Mercurio would have us believe? And who the hell is H?

To help us all streamline our notes a little, we’ve looked out some of the most compelling Line Of Duty fan theories. Which means that, yes, there are spoilers ahead, so be sure you’re up-to-date with the TV drama before reading.

And fair warning: you’ll never look at Kate Fleming (Vicky McClure) the same way again after reading these…

Is Line Of Duty season 6 inspired by this chilling true story?

Many people have taken to Twitter to suggest that the murder of Gail Vella (Andi Osho) is based on a true crime story: the murder of Daphne Caruana Galizia. 

The Maltese anti-corruption journalist, whose maiden name was Vella, made a name for herself exposing cronyism and sleaze within Malta’s elite. On 16 October 2017, though, Caruana Galizia died close to her home when a car bomb was detonated inside her vehicle,

Vincent Muscat was found guilty of murder in February and sentenced to 15 years after being convicted.

“@jed_mercurio been wondering, is #LOD6 somewhat inspired from the unresolved murder case of #DaphneCaruanaGalizia?” tweeted one viewer, after spotting the link. 

“My first hunch was the use of the Maltese surname #Vella. Also, same car model, similar journalism and similar potential motive!”

Mercurio has seemingly confirmed the theory, tweeting back: “The Gaffer has been complaining that none of the detectives out there had spotted this clue.

“He’ll probably ask you to join AC-12.”

Is Jo related to Tommy Hunter?

Line Of Duty’s original ‘Big Bad’, Tommy Hunter (Brian McCardie) wasn’t just the former leader of season one’s OCG; he was also a paedophile who abused young boys in Sands View children’s home.

Many have begun to suspect that Jo is Tommy’s daughter – which would explain why she adamantly told Farida that she has “no family.” However, it’s worth remembering that Tommy was born in 1965 and Jo was born in 1979, which would mean he became a father at the tender age of 14.

Not impossible, but… yeah. Maybe they’re siblings?

Is Jo the sister of… Kate Fleming?

It would certainly add a horrible new spin to the blossoming relationship between the pair, but countless LOD viewers have taken to Twitter to suggest that Jo and Kate are sisters. Mainly, because Kate was the only member of AC-12 who wasn’t present when the DNA results were shared.

“I’m going to go with Jo Davidson either being Jackie Laverty’s given-up-at-birth daughter or… and bear with me… Kate Fleming’s sister that Kate doesn’t know about,” tweeted one.


Is Jo the daughter of Ted Hastings?

Now, we all know that Ted (Adrian Dunbar) had a short-lived relationship with Anne-Marie McGillis, a police informant in Northern Ireland – and a lot of people have pointed out that a photograph in Jo’s flat bears an uncanny resemblance to Anne-Marie, too.

Could Jo be the daughter Ted never knew he had?

Gail Vella exposed a connection between the foster care system, the OCG, and the police

This one is pretty intense, so we’ll let Twitter user Eleanor Crossland explain it:

Now, we all know that Ted (Adrian Dunbar) had a short-lived relationship with Anne-Marie McGillis, a police informant in Northern Ireland – and a lot of people have pointed out that a photograph in Jo’s flat bears an uncanny resemblance to Anne-Marie, too.

Could Jo be the daughter Ted never knew he had?

H isn’t a person – it’s The Hill

This gem comes courtesy of avid LOD viewer Allan Ramsay, who tweeted: “The fourth ‘H’ isn’t a person, it’s a place: The Hill. A station where the OCG holds enough sway to constantly rotate bent coppers through the ranks.”

Check it out:

This theory is made all the more compelling by one of the comments beneath it, which reads: “Genius! It would also correlate to Dot’s death blinking… H [was the] first letter, [so the] second would be a vowel and he made it past G, so the second letter isn’t A or E, which exonerates Hastings.

“If he made it to I, then he could have been hinting at Hilton, who recruited him… or The Hill.”

Others, meanwhile, have tweeted a variation on this theory, noting: “H is Headquarters!”

We’re so into this.

Jo Davidson is John Corbett’s sister

As reported on 8 April: The first episode of season six saw Jo Davidson return to her apartment – her apartment which, this writer hastens to add, was locked up tighter than an escape room. 

Detective Chief Inspector Joanne Davidson
Kelly Macdonald stars in Line Of Duty season six as Detective Chief Inspector Joanne Davidson.

She then spent a moment looking at an old picture of her mum, before throwing a glass at it in rage. And, in that split second, several eagle-eyed viewers noted that Davidson’s mother looked an awful lot like Anne-Marie McGillis, aka the former police informant and mother to the late John Corbett (Stephen Graham). 

Could it be that Jo has infiltrated the police in order to seek vengeance for her dead brother?

Steph Corbett is H (or, at least, working with H)

While we’re on the subject of the Corbett family, it’s worth noting that Ted Hastings (Adrian Dunbar) used Anne-Marie as an informant back in the day.

This was a decision which a) led to John’s throat being slit in season five, and b) resulted in Ted feeling so responsible for the bent copper’s death that he gave his widow, Steph (Amy De Bhrún), a whopping £50k.

Now, many have questioned why a relatively minor character like Steph Corbett has been brought back for season six. And many have pointed out that there’s a suspicious pattern of Hs all over her kitchen, too.

Could Jed Mercurio be messing with us? Or is Steph going to give both Ted and Steve Arnott (Martin Compston) a nasty surprise before the season is out?

Chloe Bishop is Tony Gates’ daughter

Back in the very first season of Line Of Duty, Steve found himself going head-to-head with DCI Tony Gates (Lennie James). As in, yes, the bent copper who had an affair with the late Jackie Laverty (Gina McKee) and ended up doing work for an OCG as a result of his infidelity.

Tony died by suicide at the end of the first series, leaving behind a wife, Jools, and two daughters, Natalie… and Chloe.

Chloe Bishop in Line Of Duty
Many have begun to suspect Chloe Bishop in Line Of Duty.

“Holy Mother of God!” tweeted one viewer. “Has Chloe Bishop (Shalom Brune-Franklin) been ‘inserted’ into AC12 by a higher authority (’H’) to get revenge for what AC12 did to her father, DCI Tony Gates?”

Now, this could be a total red herring, but viewers have taken to Twitter to point out that Chloe Gates was last seen on screen nine years ago – which would make her roughly the same age as DC Chloe Bishop now.

Has Chloe changed her surname to protect her identity when working with the police? And, if so, is she working with AC-12 for powers of good or evil?

Kate Fleming is H

Wait, what?

Well, there have been a fair few hints that the final H is a woman – and plenty have pointed the finger at Kate Fleming, insisting she only began helping AC-12 after her former teammates learned that someone was corrupting murder investigations at The Hill. Covering her tracks, maybe?

As one viewer noted: “Kate is registered as Katherine in the system. Katherine has H in it. She’s the last one. I’m convinced.”

Then again, it seems just as likely that Kate was placed in The Hill by Ted so that she could work for AC-12 undercover.

“Do you think Hastings has put Kate undercover to investigate Buckells?” suggested one viewer. “But the side twist of Jo and the young PC???”

DS Ian Buckells is an undercover agent

We recently saw DS Ian Buckells arrested for his actions surrounding the investigation into the murder of Gail Vella… but fans have an intriguing theory about his role in it all.

As one person wrote: “I have a #LineOfDuty theory… Buckells is an undercover AC-12 agent known only to Hastings. Recruited through Masonic connection and instructed to get close to Ryan to find H.”

And one more added: “Buckells is an undercover AC-12 agent looking into Kate as being one of the Hs.”


Gail Vella is still alive

As Craig Parkinson, who portrayed Matthew ‘Dot’ Cottan in the show, said on BBC Sounds podcast Obsessed With Line of Duty: “Somebody is in that flat and there’s some connection with Gail Vella, the investigative journalist.

“You don’t cast someone like Andi Osho and then just have her as little magazine prints and stick them up on a kitchen wall.”

And the mysterious male voice on Gail’s podcast is…

Earlier this season, Steve reviewed a corrupt audio file which had been recovered from the laptop of Gail Vella.

“[Jimmy] Savile lied to cover them up,” Vella can be heard saying. “Some police officers not only accepted those lies, they propagated them. We’re losing our power to challenge lies.”

A mysterious male voice then responds: “There’s some people you can’t challenge.”

Viewers have since flocked to Twitter to share their theory that the voice belongs to none other than Jimmy Lakewell (Patrick Baladi).

For those who need a refresher, Lakewell was the corrupt lawyer of season four, who helped to cover up Operation Trapdoor and had strong links to DCI Roz Huntley (Thandie Newton).

More relevant than all of this, though? It was Lakewell who told the balaclava men where to find Steve, leading to the AC-12 copper being thrown down a flight of stairs and seriously injured. An injury which, as we’ve all seen this season, has led to him developing an addiction to painkillers.

Intriguing stuff… anyone else’s notebooks now overflowing with ideas?

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Line Of Duty season 6 airs weekly on BBC One, Sunday nights at 9pm.

Images: BBC

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Kayleigh Dray

Kayleigh Dray is Stylist’s digital editor-at-large. Her specialist topics include comic books, films, TV and feminism. On a weekend, you can usually find her drinking copious amounts of tea and playing boardgames with her friends.

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