The burning questions we need answered in the Line of Duty finale

%image(14677824, type="article-full", alt=""Definately" - (C) Line of Duty")

After the Battle of Hastings with AC-3's Deputy Chief Superintendent Patricia Carmichael, Ted is in prison having tried to trap the infamous 'H' and in doing so managed to trap himself which may, or may not be the same thing. KEEP UP THERE AT THE BACK.

We've had shocking deaths, confusing acronyms, double-crossing, entrapment and enough armed heists-gone-wrong to cast a serious shadow over the efficacy of Central Police to do anything well other than have corrupt police officers: and now it's all drawing to a close.

But we are left with questions which need to be answered in the season finale: so many questions. Here are some of them.

%image(14677825, type="article-full", alt="DCC Wise (ELIZABETH RIDER), Carmichael (ANNA MAXWELL MARTIN) - (C) World Productions Ltd - Photographer: World Productions")

The crucial questions the Line of Duty finale needs to answer

Is Lisa McQueen an undercover police officer? Lisa is a bit like Doc Martin, who is famously afraid of blood. She'll order a gangland execution and then race off to the loo for a bit of a cry and a retch – is she hiding something more than an aversion to murder? She seemed particularly affected by the deaths of Corbett and PC Maneet Bindra – is she another undercover cop? If so, why has no one mentioned her yet? Might she be in league with Hastings and on the side of the good guys? He did recognise her in the nightclub…

%image(14676128, type="article-full", alt="Line of Duty: Photo: GRABS")

Did Hastings kill Corbett's parents? We now know that John Corbett was born in Northern Ireland and has beef with Hastings who was posted in NI 30 years ago. Before John (RIP) moved to Liverpool with adoptive parents, he lived in Belfast – his father Anthony McGillis was the victim of a paramilitary murder in 1984 and his mother Ann-Marie was kidnapped after rumours that she was a police informant. When her body was finally discovered, she had been tortured in the same way that Hasting's wife Roisin had been by Corbett. Was Ann-Marie Hastings' contact?

Why did Hastings go to see Lee Banks in prison and what did the pair talk about? Lisa McQueen has admitted that the OCG had a tip-off that there was a 'rat' in the ranks from 'inside Blackthorn' and we know that Hastings went to see Banks for an off-the-record chat. Did Hastings blow the cover of DS John Corbett to pay him back for the attack on Roisin?

What's Jackie Laverty got to do with anything? In the first series, back in 2012, Laverty killed someone in a hit and run, tried to get her police officer lover DCI Tony Gates to cover up the whole thing, laundered money for the OCG, was murdered by balaclava-clad heavies and then turned up in a freezer in series five before being mixed up with Corbett's remains in a car breaking yard. Just an Easter Egg for LoD fans or does it mean more?

Is John Corbett actually dead? I mean, we didn't see a body…

Why does Carmichael hate Hastings so much? Frosty DCS Carmichael, head of rival anti-corruption squad AC-3, seems absolutely determined to bang Hastings up for as long as possible, not just for the murder of Corbett, but also told Fleming and Arnott: 'I'm going to prove that Hastings is H…' Does she have an ulterior motive?

Why did retired DCI Mark Moffatt give Hastings £50,000 in cash if not to frame him? Finding the brown envelope stuffed with cash was pretty damning for Hastings, who claimed it was an advance on funds owed to him for his failed investment in The Kettle Bell Complex in Ireland. Was it a trap? A loan? Why did Moffatt throw Hastings under the lorry?

What was on Hastings' laptop? Remember he covered it in bubblewrap and took it to be destroyed at a computer disposal facility? Why? We know that Hastings was using the same messaging software as the OCG, but does he have incriminating evidence that he needs to have wiped?

Gill Biggeloe: friend or foe? She's AC-12's former lawyer and she was conveniently with Ted while his wife was trying to reach him to verify Corbett's story when he went to the couple's house to attack her. She's legal counsel to his bosses and she seems to be a mass of contradictions, the largest of which being serving Ted with his notice and then offering to be his defence solicitor. What's her game?

That 'definitately' typo: The OCG's contact misspelt definitely several weeks ago using the messaging system and we've seen Hastings make the same mistake. Does this mean that he's H or is he a detail freak? Or just someone that can't spell?

Are AC-12 destined to live miserable lives? Hastings is banged up in a small room with a dodgy toilet which is similar to his lodgings which boasted a small room with a dodgy toilet, DI Kate Fleming's husband Mark is annoyed because she's always at work and is neglecting their son and DS Steve Arnott was on a promise with ex-girlfriend DS Sam Railson but performance issues sent her packing.

The million dollar question: is Hastings H? We were certainly led to believe that Hastings was H. Then we were led to believe that he wasn't. Is it a double-double bluff? Only Jed Mercurio knows the answers – and with at least another series pencilled in, the likelihood of finding out the answer to this mystery is fairly low. From the sheer number of furtive glances and huffing that Hastings has been doing, the likelihood is that Mercurio is leading us up the garden path. Or is he? MY HEAD, MY HEAD!

*Line of Duty's series five final airs next Sunday at 9pm on BBC One