It’s been a long old wait for the new series of Line Of Duty, which was an early TV casualty of the pandemic last year when filming was suspended for six months. 

Sunday night finally saw the famous trio of Fleming, Arnott and Hastings back in action – although things were very different in the set up of AC-12 to when we last saw the team. 

It was revealed that DI Kate Fleming had left the anti-corruption unit to joining the major investigations team (MIT), who appeared to have just made a breakthrough in their investigation into the murder of journalist Gail Vella. 

However, a decision to stop the police convoy en route to arrest the suspect – on a mere hunch that an armed robbery was taking place at a betting shop – immediately put MIT boss DCI Joanne Davidson under AC-12’s spotlight. 

It soon became apparent that this new story has plenty of links to previous series, and left us with a hell of a lot of questions as the credits rolled…

1. Who really killed Gail Vella?

We are not buying that Terry Boyle was responsible for Vella’s murder, as we have previously seen him manipulated and bullied by the OCG in both series one and series five. That means the likelihood is that they are setting him up as their fall guy. 

2. Why was Gail Vella killed?

The motive for Vella’s murder was not explored in the first episode, but from the series trailer, we know she had previously reported on police corruption and officers’ involvement with organised crime in her capacity as a journalist. 

Perhaps she was working on a big exposé prior to her death that the organised crime group (OCG) and the corrupt officers in league with them found out about, and thus ordered her death?

3. Who is “Ross Turner”?

Is this a real person or just a false name? 

4. Who is Carl Banks?

Banks’ prints were found all over the Beechwood House flat, and the name Banks immediately made us think of OCG member Lee Banks, who Hastings visited in prison during the last series. Could he be a relation?

5. Who killed the CHIS?

The informant who had tipped MIT off about “Ross Turner” was found dead after falling off the top of a building, after presumably being pushed. Despite not seeming to not know his identity, could Davidson have ordered his death so she could pin the charges on Boyle and close the case?

6. What did Jatri mean when she said “you don’t know what [Davidson] is capable of”?

Because of their previous relationship, Sgt Farida Jatri obviously knows DCI Davidson better than any of her colleagues, and warned DS Steve Arnott that she was dangerous.

What has she witnessed in the past to make this allegation? Or is she merely a scorned ex mourning the loss of her relationship and seeking revenge?

7. Have Fleming and Davidson had an affair?

While Davidson dismissed Jatri’s accusation that she’d been having an affair with Fleming prior to the end of their relationship, there was a moment of tenderness between them at the station that suggested there could be some truth to Jatri’s suspicions. 

We also know that Fleming has split once again from her partner, having reunited with him and their son in the last series. 

8. Why is Davidson lying about her family?

During her row with Jatri, Davidson claimed she “didn’t have” any family, but when she returned to her apartment, there was a photo of her with someone we assume to be her mother. We then saw her becoming angry and throw a glass at the photo, so what is the real story between Davidson and her relatives?

9. Why does Davidson have so many locks on her door?

Does she believe she is someone’s target? Or is there something in the flat she is desperate to stop someone finding?

10. Is Fleming’s life in danger now she is a CHIS?

Despite having left AC-12 behind, she’s been pulled back into the world of anti-corruption when DS Arnott asked her to act as an informant on her new department. 

A trailer for the new series suggested a character’s life would be on the line, so could Fleming’s latest covert operation go horribly wrong and end up seeing her pay the ultimate price – especially after what happened to the last CHIS? Writer Jed Mercurio has previously refused to rule out the possibility a major character could be killed off… 

11. Is there more to Fleming’s exit from AC-12?

In a conversation between Fleming and Arnott, she claimed to have moved on from AC-12 after the department became tainted, thanks to the official investigation into Superintendent Hastings’ conduct. 

Some fan theories have previously suggested that Fleming could be the fourth officer working with the OCG, and if this is true, then a move to MIT would certainly have enabled her to help cover up any potential involvement they had in Vella’s murder. Could this be the real motivation for her sudden career move?

12. Why has someone taken the fridge in Boyle’s flat?

It was revealed that Boyle’s flat was cleared out and cleaned up, apart from the pictures of Vella hanging on the wall that were found to have traces of semen on them. 

What you might have missed during this interrogation scene though – especially if you are a relative newcomer to Line Of Duty – is the significance of the moved fridge in his kitchen. 

Last series, it was revealed the fridge is where the OCG were storing some remains of Jackie Laverty – the former lover of series one antagonist DCI Tony Gates, who was killed when the OCG broke into her house and used her murder as leverage to manipulate the cop. 

Parts of Laverty’s remains were later disposed of along with John Corbett’s body by the OCG in the McDade & Company Breakers Yard in series five. 

So why has the fridge been moved? Are there more of Laverty’s remains out there? And if so, what does the OCG plan to do next?

13. Did DCI Buckells mess up the surveillance on Beechwood House on purpose?

The address where Boyle was found wasn’t watched for three hours due to Buckells messing up the paperwork, meaning the real “Ross Turner” could have escaped during this time. 

While he did pop up in series four, we can’t help but think his reappearance in the story at a time when the Laverty story is being revisited is significant. Is he also caught up with the OCG?

14. Is Davidson really a bent copper?

Well obviously we’re not going to now how corrupt she is just yet, but things are definitely not adding up when it comes to Davidson’s decision to stop the convoy to attend to the armed robbery at the bookies’…

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

UPDATE: This article has been updated to reflect that some of Laverty’s remains were disposed of by the OCG in series five.