Here's what happened in Line of Duty season 6 episode 6 – and all the major questions we have before the finale

The episode gave us a lot of answers, but also raised quite a few questions. Here's the recap – as well as the questions we're still pondering.

1. Who did Jo think her father was?

"My mum was Tommy's sister. My dad was bent. A police officer," Jo Davidson told DI Kate Fleming (Vicky McClure) in the car, as they made their Thelma & Louise getaway. But later, in her AC-12 interrogation, Carmichael told Jo some devastating information about her true parentage. DNA analysis detected "runs of homozygosity" indicating that Tommy Hunter was not only her uncle, but also her biological father. No wonder a single tear fell from her eye onto her prison sweatshirt; she seems genuinely not to have known.

So... who was Jo referring to when she talked about "my dad"?

Jo has now revealed that her mother, Samantha Davidson, told her that she'd been raped at the age of 15 – and become pregnant. "I never knew the details," Jo said. Samantha was born into a criminal family, and her brother Tommy Hunter – who must have only been about 12 years old at the time, if police records are correct – was already on his way to criminal leadership.

Teenage Samantha Hunter was sent to Glasgow under her mother's maiden name, and so became "Samantha Davidson". She gave birth to Jo and raised her for the next 16 years, but at that point Tommy "came looking" and told his high-achieving niece (and secret daughter) that she had to join the police force and do his bidding. Samantha knew she couldn't protect young Jo from "Uncle Tommy", and took her own life. Jo joined the police at 19, and has been trapped into doing the OCG's bidding ever since.

So, when Jo told Kate about "my dad" the bent copper, she clearly wasn't referring to Thomas John Hunter. Which means there are two options. Option one: was she referring to a man who she thought was her biological father? If so, she'd be referring to a man she thought was her mother's rapist. It's possible, although she did say she was never told "the details" of her mother's rape. But maybe young Jo was told that a senior figure in the police force was her mother's rapist, and maybe she's believed it ever since.

Or, option two: was Jo referring to an adoptive father, who raised her as his own? This seems more likely. It also means that Jo would never have to fear being connected to this man by DNA analysis.

But Jo now refuses to tell AC-12 about her father. "This person, did he control you the same way Tommy Hunter did?" Steve asked, but all he got in response was a "no comment".

That said, Jo did react (a lot) to the name and image of "Marcus Thurwell", who is a plausible candidate. Another prime candidate would be Chief Inspector Philip Osborne (Owen Teale) himself. We've rounded up all the theories about Jo Davidson's 'father', so take a look at that article for more.

2. Why did Kate run away? What was her gameplan?

We're still slightly baffled by Kate's decision to do a runner from the lorry park after shooting Ryan Pilkington dead. To recap: She and Jo jumped in her service vehicle, abandoned that vehicle, headed to Steve's garage, took his car keys and a burner phone, and borrowed his car for a drive through town.

But what was the plan here?

Because really, Kate had no need to flee arrest. She was fully authorised to carry a firearm, and she clearly shot Ryan in self-defence. He was pointing an illegal workshopped gun at her, he'd made Jo lure her to the rendezvous, and AC-12 has evidence that Ryan was an OCG mole. There might have been some fuss about it all, but Kate should probably have just stayed put and waited for forensics to turn up.

If she left the scene because she was trying to protect Jo, that also seems very ill-advised, especially as Jo had literally just arranged Kate's murder.

Plus, the police were always going to find her and Jo eventually. Admittedly it would have taken a little longer if Osborne hadn't put a tracker on the car – something that neither Kate nor Steve knew about, which is why Kate freaked out that she'd been set up (and why she feared that Ted and Steve betrayed her). But when she almost refused to surrender to the police at gunpoint: Kate, what were you doing?

If she and Jo had more time before the police found them, they might have recovered Gail's computers from the Kingsgate print shop – and been able to provide that as a peace offering.

But still. Kind of a silly thing to do. And Kate was even letting Jo direct the car, so it doesn't seem like she had any plan at all (except for fleeing the lorry park asap).

3. Did Jo know that Gail Vella was looking into the Lawrence Christopher case?

Jo's policy during her AC-12 interview seemed to be that she'd tell no lies, except for the big one – i.e. claiming that she was the one who killed PC Ryan Pilkington (Gregory Piper), not Kate. Aside from that, she either A) told the truth or B) gave a "no comment".

During the course of the interrogation, she gave a lot of "no comment" responses. But after persuasive questioning from Steve and Ted, she did confirm a few things: she was the one who alerted the OCG to the raid on "Ross Turner", so a decoy could be set up; she ensured the wrong surveillance authority was requested, on purpose; she framed Farida; she planted the files in Buckells' car; she steered the inquiry away from organised crime; and she was meant to frame Terry Boyle, but she just couldn't bear to do it.

So, when Jo said she didn't know anything about the Lawrence Christopher case, Darren Hunter's involvement, or what Gail Vella was looking into... well, we were inclined to believe her, despite the fact that Superintendent Ted Hastings (Adrian Dunbar) didn't.

After all, Jo has spent her entire career being forced to follow the orders of Tommy Hunter and his successor(s). Why would they feel the need to give her the full picture? Wouldn't it be much easier and safer just to give her orders and information on a need-to-know basis?

Make sure to check out how Line of Duty based the Gail Vella narrative on a true story.

4. Is Philip Osborne 'H'?

Chief Constable Philip Osborne is looking fishier by the minute, so he's either "H" – or Jed Mercurio wants us to suspect he's "H".

In particular, we're thinking about how freaked-out Jo Davidson was by any mention of "H" or "the Fourth Man" during her interrogation. When Ted commanded her to tell him who ultimately gives the orders, she broke from her usual "no comment" line to say something more revealing: "I can't. I'm sorry."

If Osborne is "H", that would explain why she really couldn't say. He is too senior a figure to accuse, and he has the power to punish those who cross him. But Ted clearly also has Osborne on his radar, asking Jo: "Is. It. The. Chief Constable?"

And then there was that closing montage, with Osborne's speech cut over the top. "For too long now, police officers have had to serve faceless, unaccountable bureaucrats. We've even had to suffer political opportunists, trying to win votes by vilifying police officers with false allegations of corruption. We must defend this constabulary from those who would obstruct us in serving the public. Not only does this force face enemies without, there are enemies within. I will personally see to it that those enemies within are made to suffer the consequences." Suffer the consequences!

5. Is Carmichael bent – or just ambitious?

DCS Patricia Carmichael (Anna Maxwell Martin) is one of Line of Duty's best (and most loathsome) villains so far, as Michael Hogan writes for RadioTimes.com in his ode to Carmichael. But since season five, we've been wondering whether she's simply ambitious and vengeful, or whether she's actively bent. Is she an unwitting tool (in both senses of the word) who is superciliously doing someone else's business? Or is she, in fact, entirely witting?

In this episode, her desire not to let Ted question Jo Davidson about the bigger picture of police corruption... well, it was actually almost laugh-out-loud funny.

"Is it Osborne?" asked Ted, before Carmichael jumped in quick-as-you-like: "I think we'll leave it there." And again, with a hiss: "The interviewee has repeatedly claimed she didn't know about any. of. thissss. It's a dead end."

Again and again it happened! "I would prefer to confine myself to the set parameters of the anti-corruption enquiry. Let's chivvy things along, shall we?" she said. And when Ted said "we have identified a number of high-ranking figures in a clandestine network of corrupt police officers," she was quick to butt in with a correction: "hypothetical network."

Also, Carmichael had DC Chloe Bishop (Shalom Brune-Franklin) take Osborne's picture off Ted's pin board and put it through the shredder. Symbolic!

It's clear that Carmichael's loyalties lie with Osborne. "The Chief Constable and I don't trust you," she told Ted, snidely, when he objected to Osborne secretly installing trackers on his officers' personal cars. But is this because she's in league with him on some bent-copper-business? Or because a great relationship to Osborne has been incredibly beneficial to her career, and she doesn't want to jeopardise that? So far, so unclear.

6. Is Buckells actually bent after all?

First we thought DSU Ian Buckells (Nigel Boyle) was maybe more bent than incompetent. Then we thought he was more incompetent than bent. And now, we have to ask again: to what extent is (or was) Buckells working with the OCG?

The fact that then-DC Buckells was involved in the 2003 Lawrence Christopher case – alongside Marcus Thurwell and Philip Osborne – is very interesting. If Gail was murdered in order to stop details of that cover-up coming out, then Buckells might know something quite important about what happened back then. No wonder Blackthorn Prison's Lee Banks (Alastair Natkiel) killed Jimmy Lakewell (Patrick Baladi) in Buckells' prison cell, just to warn him what happens to rats.

And it now emerges that Buckells was the one who – in an uncharacteristically pro-active move – had Operation Lighthouse's first SIO taken off the case, and replaced with Jo Davidson. And it may have been Buckells who secured Ryan's appointment onto the MIT, too, as Jo says he was imposed against her will. Was someone leaning on Buckells?

That said, Buckells and Davidson don't seem to have been kept in the same loop by the OCG, despite both working on Operation Lighthouse.

Davidson was working solo on her plan to divert the convoy on the way to the "Ross Turner" (Carl Banks) arrest, revealing that she manipulated Buckells into signing off the wrong surveillance authority ("it wasn't hard").

Perhaps Buckells, not being the sharpest crayon in the box, was only given instructions/information on a need-to-know basis. But it's still unclear at this point whether Buckells put his ex-lover Deborah up to giving a false witness statement against Terry Boyle (the man Buckells wanted to convict), or whether someone else set that up.

With the full backing of the Chief Constable, Carmichael is working hard to clear Buckells' name, now, anyway – so let's see if he gets away with it.

7. What's under the floor of the gun workshop?

"You look at the weight of those. No way were two OCG men on their own going to move them," Steve pointed out, proving why he'd been made DI. And yes, when you think about it, what were beardy Lewis and that other bloke planning to do at the gun workshop, before AC-12's team of AFOs shot them dead?

The materials the men had in their van included tarpaulins, rope, pickaxes, wrenches, power saws, and power drills. Unless they were planning on just covering the machines up with tarp and hoping for the best, they must have been sent to do something else.

"Right, let's call out the GPR and find out what's under that floor," said Kate. But what could it be? Thinking about the OCG's track record, we could be looking at: dead bodies, incriminating evidence against police officers, cash, guns, or weapons of various varieties. And those are all the things that police regularly use GPR (ground penetrating radar) to seek out.

8. Who's in charge of the OCG now?

At the start of Line of Duty, the OCG had one clear leader: Tommy Hunter. But six or seven years later, things are not so straightforward.

Jimmy Lakewell once said "not balaclava man, balaclava men". Similarly, what if it's "not OCG, OCGs"?

Because, in her interrogation, Jo contradicted Steve's assumption that someone else replaced Tommy at the top of the OCG. Instead, Jo explained, "Tommy held it all together. It broke up into disparate elements, smaller OCGs. The only thing that united them was how much they stood to lose if Tommy carried out his threat."

So, despite witness protection, Tommy was murdered at the start of season two. "Tommy had cultivated relationships with corrupt police officers, but they started to turn against him. he felt betrayed, so he threatened to expose them all," Jo explained, claiming that both OCG members and police officers (including DI Dot Cottan) were involved in getting him killed. Tommy threatened to ruin a good thing.

If the OCG has splintered into multiple OCGs, that could complicate matters – and add confusion to the question of who's been sending Jo her orders since Tommy died.

It's true that there has been a core group of criminals we've seen again and again: young Ryan and Miroslav Minkovic (Tomi May) were working with Tommy in season one, and by season five they were both part of the same OCG unit with Lisa McQueen (Rochenda Sandall) and Lee Banks (Alastair Natkiel). But that OCG unit was receiving orders from above – from a figure who UCO John Corbett (Stephen Graham) believed was "H" – and, since Tommy Hunter's departure, it's possible there has been no clear criminal leadership.

9. Who killed Marcus Thurwell – and is he really dead?

Watched by AC-12 via video link, the Guardia Civil in Spain raided the home of Marcus Thurwell (James Nesbitt) – but found him dead, alongside someone who they immediately identified as "Señora Thurwell". From the grainy footage, it looked like they'd both been shot; they also been dead long enough to start attracting flies.

So the first question is: who killed Marcus Thurwell, and why? Was this the OCG, killing off an old police collaborator in case he talked? In fact, what if he did talk to Gail Vella?

And the second question is: c'mon, is he really dead? Perhaps the Guardia Civil are in on it, and have staged this raid to throw AC-12 off Thurwell's scent. After all, we don't see Thurwell's actual face in the footage. It could be anybody's dead body in that Spanish villa, and we'd be none the wiser.

10. Is the prison officer going to attack Jo Davidson?

Steve reckons Jo Davidson is safe behind bars, because they've put her in the VPU ("vulnerable prisoner unit") at Brentiss Prison. But we wouldn't be so sure about that. Because Brentiss Prison's nastiest, most corrupt prison officer Alison Merchant (Maria Connolly) is prowling the corridors, just waiting for her chance to get at Jo – just as soon as she can disable the CCTV.

We know Merchant from her previous arm-based acts of violence on behalf of the OCG. In season two, she was the one who switched off the CCTV so a couple of other prisoners could attack DI Lindsay Denton (Keeley Hawes) in the exercise room, then took her into a side room and poured boiling water over her arm, ordering her to stop talking to AC-12.

Then, in season six, she accused Sergeant Farida Jatri (Anneika Rose) of resisting having handcuffs put on so she could be taken to her AC-12 interview – and took her chance to break poor Farida's wrist. Farida has since refused to talk.

Now, Merchant and her sidekick are clearly scoping out the cameras around Jo Davidson's cell. Do they have orders from the OCG and/or "H" to kill her? Or to commit another violent, maiming attack as a warning?

11. Will Steve go to Occupational Health – or get suspended?

In case you didn't get a chance to read that email from Occupational Health in full, here it is, with the subject line "FINAL WARNING": "As you have failed to attend your compulsory appointment, you are hereby notified that, unless you attend a Medical Review within 5 working days, we will have no choice but to recommend you be suspended from duty and receive a Yellow Notice under Police Conduct Regulations."

Occupational Health isn't messing around any more. But will Steve leave it till the last minute and make an appointment, or will he actually let himself get suspended from duty? Presumably he's planning on the former strategy, hoping that he can get the current case sorted within the next week – and then submit to the Medical Review.

We already know that Steve is terrified doctors will ban him from active duty thanks to his serious back injury, and/or because of his painkiller addiction.

12. Is Ted going to be forced to retire?

This cannot be the end of AC-12, surely. But things are looking quite bleak for Ted at the moment; the gaffer, who lives and breathes anti-corruption, is being forced into early retirement – and Carmichael is already attempting to inch him towards the door.

That means the clock is ticking for Ted to blow this whole thing wide open. But now, at the most important moment, Ted is losing faith that he'll be able to get this thing done. As he told Steve: sometimes you don't lose, you just run out of time. Oof.

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13. Has Kate really got away with killing Ryan?

As a big gesture, Jo offered to take the rap for Ryan's shooting. And surprisingly, Kate accepted – holding out her gun so that Jo could cover the grip and the trigger with her own fingerprints.

In her interrogation, Jo then fed AC-12 a barely-plausible story about how she killed Ryan using Kate's gun. She also pointed out that it was both lawful and necessary to shoot him.

Everyone knows that Jo is lying, to protect Kate. Steve knows. Ted knows. And most importantly, Carmichael knows – and at this point, she's prepared to overlook it, if Jo wants to take the blame and make things less complicated. "I'm not gullible, but I am pragmatic," as she told Kate.

But the one big downside: Carmichael now has something over Kate, which she could try to use in future.

14. What will they find on Gail Vella's computers?

Presumably, the OCG has made a good attempt at wiping the hard drives of the computer and laptop they stole from Gail's flat. But might the police recover any further data, documents or audio files?

Hopefully the hard drives end up in the hands of AC-12's Amanda Yao (Rosa Escoda), and hopefully Carmichael doesn't get in the way, because Amanda has so far proven herself to be a tech genius. If anyone can dig out files from a wiped hard drives, it's her.

And if anything is rescued off the hard drives, it could provide crucial information unlocking the Gail Vella murder case and exposing wider police corruption.

15. Will charges against Farida be dropped?

Poor Farida Jatri has been somewhat forgotten in all of this. But now Jo Davidson has admitted to planting the burner phones in her house to frame her, hopefully she'll be released from prison (if that's where she still is – we've not seen her in a while) and have all charges against her dropped.

Buckells is the one who's been agitating about wrongful imprisonment, but really it's Farida who has had the raw deal out of this – especially with her broken arm. Plus, her house has been combed over by two separate forensics teams. What must the neighbours think?

If you also can't wait until next week, watch the Line of Duty finale trailer here now.

Line of Duty concludes on Sunday 2nd May 2021 at 9pm on BBC One. Take a look at the rest of our Drama coverage, or check out our TV guide to see what's on this week.