We don’t know about you, but we are currently drenched in sweat after that ridiculously tense ending to Sunday’s Line Of Duty. 

DI Kate Fleming’s life hung in the balance as she had an armed stand-off with Ryan Pilkington in the final moments of the episode, before two shots ominously rung out. 

The moment came at the climax of the most shocking episode yet, which also revealed DCI Joanne Davidson is related to former OCG boss Tommy Hunter – as many fans correctly predicted. 

Elsewhere, AC-12 made huge strides into their investigation into journalist Gail Vella’s killing, after finding out she’s been looking into police corruption in the 2003 murder of Lawerence Christopher prior to her death. The architect was racially attacked in the street by a gang of white youths, but was mistakenly taken into police custody after a passer-by called 999, where officers laughed and made racist slurs as he lay dying in his cell. 

As details of a subsequent police cover up with connections to organised crime began to emerge, there were a hell of a lot of questions to discuss as the credits rolled…

1. How are Davidson and Hunter related and what was that word Arnott said?

While it emerged that Davidson and Hunter were related, it wasn’t terribly clear exactly how, as Arnott told Fleming and Hastings that there was “an unusually high percentage match that runs to homozygosity”. 

If you’re not familiar with genetic terminology, you probably won’t have realised this term refers to the “the genetic condition or the genetic state where an individual has inherited the same DNA sequence for a particular gene from both their biological mother and their biological father”. 

2. Who was Davidson speaking to on the laptop?

The misspelling of the word ‘definitely’ points to it being the same person who was suspected of being ‘H’ in series five, suggesting the so-called ‘fourth man’ is still calling the shots on this operation. 

The biggest question remains though: who is it?

3. Just who is Marcus Thurwell?

Prior to the episode airing, it was revealed that a BBC website had accidentally leaked the identity of a well-known actor joining the cast of Line Of Duty, who was revealed as Cold Feet star James Nesbitt on Sunday night. 

While we are yet to see him in action, his pictures were used as AC-12 looked into the Lawrence Christopher case, which revealed he’d been the senior investigating officer on. 

He is suspected of a cover up that allowed the suspects of the racist attack on Christopher to escape justice. One of the suspects happened to be the son of former OCG boss Tommy Hunter. 

Long-standing Line Of Duty fans might have already recognised Thurwell’s name from series three, as he was the senior investigating officer on the 1998 murder of Oliver Stephens Lloyd – a care worker who was investigating the allegations of abuse at the Sands View boys home. 

While his death was ruled as a suicide, AC-12 later discovered evidence to reveal he was murdered by the OCG, suggesting there had been a cover up on the original investigation.

Hunter was on Danny Waldron’s list of names who were responsible for the abuse of young boys at the home, suggesting he and Thurwell had a pre-existing connection, and Hunter ordered him to sabotage the original inquiry into Christopher’s death to protect his son. 

While Thurwell is now thought to be living in Spain, reports have suggested that we will be seeing him on screen in upcoming episodes… 

4. What was the reason for Vella’s murder?

Journalist Gail Vella seemed to have established the link between the Lawrence Christopher case and the Sands View boys home scandal, but was murdered the night before she was due to interview former officer Patrick Fairbank in prison about his involvement at Sands View.

Arnott revealed he believes that Vella was murdered to protect someone else in the original inquiry, which means that the officer wields a high level of influence over OCG, suggesting this man is Thurwell. 

5. Did Thurwell order Vella’s murder?

Thurwell was not the only familiar officer who worked on the original inquiry into Lawrence’s murder – so did DSU Ian Buckells and Chief Constable Philip Osborne. 

We already know that Osborne covered up what happened in the killing of Karim Ali back in series one, so we would not be shocked to find out he was complicit in sabotaging the Lawrence inquiry. 

Given he’s now at the top of Central Police with the most to lose from the truth coming out, was he actually the one who ordered Vella’s murder, and thus is also the ‘fourth man’? 

6. Does PCC Sindwhani know more about Osborne than he’s letting on?

Revealing he was resigning from his post, the PCC claimed to have been “thrown under the bus” by Osborne, claiming that if he does nothing about his plan to scale back anti-corruption operations, he’s weakened, and if he fires him, Sindwhani would lose the support of other officers.  

He then seemingly encouraged Hastings to go after Osborne, which suggests he also believes the Chief Constable is corrupt. 

However, we’re still in two minds about Sindwhani, as don’t forget AC-12 discovered he walked out of an interview with Vella when she pressed about the Sands View boys home scandal. 

7. Is Carmichael bent?

The return of DCS Patrica Carmichael was as glorious as we’d been hoping for, but we soon became highly suspicious of the AC-3 boss. 

She’s a plant of Chief Constable Philip Osbourne – someone who we now know is heavily corrupt – and has taken it upon herself to withdraw the surveillance on Pilkington and Davidson, just as AC-12 were making progress on the case.  

She claimed this was down to budgetary issues, but something is telling us there’s something more sinister to her promotion and subsequent decisions….

8. Did Arnott do anything with the info he gained about Hastings?

Carmichael’s premature arrival at AC-12 might suggest Arnott reported Hastings to his superiors, following his own investigations into the gaffer. 

However, if you remember in series five, Carmichael was determined to prove Hastings had tipped Lee Banks off about John Corbett’s real identity but was told to drop it by DCC Andrea Wise when the scheme to fit Hastings up as ‘H’ was uncovered. 

With it now confirmed Hastings had a hand in Corbett’s death and also gifted his widow £50,000 of dirty money he’d received from Mark Moffatt, surely Carmichael would have pulled him straight in for questioning as her first act, rather than derailing AC-12’s inquiries?

Does this suggest Arnott is still sitting on what he knows?

9. What happens next to Hastings?

We’re guessing that Hastings tipped Lee Banks off as revenge against Corbett for his brutal attack on Hastings’ ex-wife, which came before the revelation Hastings and Corbett had a personal connection due to the gaffer’s former dealings with his mother Ann Marie McGillis. It would therefore make sense that Hastings was paying Steph out of guilt for his role in Corbett’s death. 

But even if this is the case, it’s not going to wash under questioning, if indeed Arnott has spilt about what he knows. 

10. Why did Hastings change his mind about pulling in Pilkington? 

Hastings was the one who originally suggested AC-12 should play their hand with Pilkington, but was dissuaded by Fleming. 

However, in scenes from episode five, Fleming called for the team to pull him in, only for Hastings to go against his original judgement and keep him under surveillance in the hope he would lead them to ‘the fourth man’. 

Is there more to this decision? One theory (which feels unlikely to us) might be that Hastings is the fourth man and wants to use Pilkington to dispose of Fleming. 

11. Is Fleming dead?

You’ll have noticed that two shots rung out following Fleming and Pilkington’s armed stand-off, which suggests a number of scenarios. Either they shot one another, or a – likely fatal – double shot was let off by one of them. 

If either or both were injured, will they die?

You might think it’s implausible that a character as central as Kate Fleming could be killed off, but as long-term fans will know, Line Of Duty creator Jed Mercurio has history when it comes to bumping off major characters. Just think about The Caddy, Danny Waldron and Lindsay Denton, to name but a few. 

However, before you start prematurely mourning Fleming, there’s a suggestion in the series trailer that she survives. 

In the scene that is yet to air on TV, Davidson is seen wearing the same clothes in the same setting, saying: “Kate, I had nothing to do with it.”

Fleming is also seen standing opposite her in the clip. 

Could this be proof Fleming survives? Or is it just taken from a scene that has since been left on the cutting room floor? Perhaps even a red herring that’s been deliberately placed in the trailer to make us think exactly this?! After all, we’d put nothing past those sneaky Line Of Duty bosses. 

12. What happens to Davidson now?

If indeed Fleming does live to fight another day, it means the writing is well and truly on the wall for Davidson, as her corroboration with organised crime having been exposed to her colleague. 

Even if Fleming doesn’t survive, another scene from the series trailer suggests that police soon arrive at the location as Davidson is seen holding her hands up. 

We can almost taste the delicious AC-12 interrogation scene that awaits us.

Line Of Duty continues on Sunday at 9pm on BBC One.

CORRECTION: This article previously stated that Jo Davidson and Tommy Hunter were siblings, which is now not believed to be the case.