Ranking every Line of Duty cop by who is most likely to be H

It's all come down to this

The series finale of Line of Duty on Sunday May 2nd is set to be one of the most explosive - in every sense - episodes of British drama television in recent memory. Show creator Jed Mercurio has treated us all to an extra episode this series, and looking at the huge number of intertwined plot lines that need wrapping up, you can see why they needed it. But we're really all waiting for one revelation on Sunday night. Who killed Gail Vella is now very much secondary in the search for the "fourth man... (or woman)" who has led institutional corruption within the force from the very start. So who is 'H'? Will we even find out? I hope so, because if they don't wrap this up in the next episode and instead decide to drag it out for another series, I can see it following the same trajectory as Game of Thrones and entering silly territory. And nobody wants that. So without further ado, here are the nine most significant coppers remaining on the show, ranked in order of their likelihood of being 'H'. Starting with the least likely.

Kate Fleming

It can't be Kate. That would be the greatest betrayal of story-telling logic since Bran was crowned King of Westeros in Game of Thrones, purely because the writers needed to rush the ending. Kate has been fighting tooth and nail to uncover corruption within the force from the very start, undergoing numerous undercover operations. The fact she fled the crime scene after shooting Ryan Pilkington does raise a few suspicions, given she acted in self defence, but I just can't buy into the theory that she is H. Alright, mate?

Steve Arnott

The same goes for Steve. Sure, he's slept with a couple of witnesses, and yeah, he still hasn't made that appointment about his drugs test - and I do expect this to play a significant role in the final episode - but there's no chance of him being bent, let alone him being H. As a theory, it's a non-starter.

Chloe Bishop

Chloe has been an excellent addition to the cast this series. Her passionate response to Steve asking her if she was ok after discovering some horrible truths about the Lawrence Christopher case was very moving, and her detective work has been helpful (don't hold me to that if there's a massive twist in the finale). There is a strong theory that Chloe is actually related to Tony Gates from series 1. If you cast your mind back to 2012, or whenever you watched the first series, you might recall Tony has two daughters, one of whom is called Chloe. It would make sense that she wanted to join the police force in honour of her father, who died in the Line of Duty, but preferred to use her mum's maiden name in order to suppress any links between her and her dad, who got tied up in some naughty business with the OCG. Does this mean she's bent, though? Not necessarily. [caption id="attachment_271226" align="alignnone" width="2048"] Tony Gates playing with his daughters Chloe and Natalie[/caption]

DSI Jo Davidson

We know Jo has been caught up in the OCG's operation, and she is not innocent in the cover up of Gail Vella's murder. Ryan had her over a barrel and she had nowhere to turn, having seen what happens to a rat. We also know Tommy Hunter was her uncle and, tragically, also her father. But crucially, we also know she's not calling the shots. Kelly McDonald's performance in the 30-minute long interview scene in the previous episode was sublime and brilliantly conveyed the helplessness Jo is currently feeling. Like other SIOs on the show - Huntley, Gates et al. - she has been put into a position of relative power so that the OCG can use her to steer attention away from their crimes, as they try to frame innocent people like Terry Boyle and Michael Farmer for murders.

Ted Hastings

The strongest piece of evidence pointing towards Ted Hastings being H might appear rather minuscule in the grand scheme of things, but if the series finale trailer is anything to go by, it will play a huge part in discovering H's true identity. That's right, the typo. We know that whoever is behind the 'Unknown' account on the messaging service used to communicate with both John Corbett in series 5 and Jo Davidson in series 6, can't spell 'definitely'. We also know that Hastings, while pretending to be H on the same communication service, misspelt the word in the same way. The same mistake then appeared in series 6, when Jo Davidson was told by 'Unknown' that "Eastfield Depot is definately high risk." This has obviously fuelled some fan theories that Hastings is H, and while it's probably no coincidence, it seems more likely to be a red herring than fool-proof evidence to prove that Ted has been pulling the strings all along. But rest assured, this will come up in the finale–the trailer revealed one shot of the typo highlighted. But the question is: whose handwriting is that?

Ian Buckells

Buckells is clearly knee deep in corruption. But as we saw during Jimmy Lakewell's murder scene, he doesn't exactly have the cojones to lead a group of corrupt officers. If he can't watch a murder without shaking in fear (which everyone with any sort of human compassion would do, I want to clarify) how are we meant to expect him to be H? He's a useful idiot for the OCG but it's unlikely to be Buckells who is orchestrating the entire operation. He can't even pour milk into a mug.

Patricia Carmichael

Right, now we're onto the actual contenders. Carmichael's return threw a real spanner in the works as she broke the news that AC-12's days were numbered, and that she would be taking over their operation, limiting what Ted and Steve could do in their quest to uncover the truth behind Gail Vella's murder and the broader network of corrupt officers. There is quite a stack of evidence that points towards Carmichael, some of it trivial, some of it more substantial. The fact that she tapped her pen four times during the interview scene, spelling out H in morse code, is not concrete evidence of anything but is surely left in the edit for a reason - they want us to think it could be her. Then there is the quite frankly absurd theory based on an anagram. This theory claims that when Jimmy Lakewell told Steve to "look deeper into the race claim", he was supposedly talking about Carmichael, because if you rearrange the letters in 'race claim' and add an H, it spells out Carmichael. It does, to be fair, but if Lakewell expected Steve to decipher that, he was stupider than I thought. However, her close ties to the chief constable and her personal mission to destroy AC-12 and all of their hard work is a strong enough case to put her third on this list.

Marcus Thurwell

You don't hire James Nesbitt to be a mug shot. And you probably don't kill him off before he's said anything. Viewers are right to be suspicious of the raid in Spain, watched by AC-12 via video link. I'm not convinced Marcus Thurwell is dead, and I'm expecting him to be involved in the finale somehow. Equally, though, I'm not entirely convinced by the theory that this Guardia Civil officer is Marcus Thurwell just because they have similar eyes. We know he was the SIO for the Lawrence Christopher case, and that he was involved in the Sands View scandal, before the Crown Prosecution Service's pursuit of him was dropped once they caught Patrick Fairbank. While he has been mentioned in passing in previous series, he is relatively new to the story, which gives me a hunch that he's been the illusive H all along.

Chief Constable Philip Osborne

Osborne was the very first example of corruption that we saw in the first series, when he removed Steve from his unit for refusing to take part in the cover up of their botched anti-terror operation. It would make sense, purely from a story telling perspective, for it to come full circle and transpire that Osborne is the "fourth man." It was revealed earlier in series 6 that he was part of Marcus Thurwell's investigation into the Lawrence Christopher case, and now he is trying to shut down AC-12, just as they begin looking into it. Add all of this to the fact that he's failed upwards all the way to chief constable, and he seems the most likely candidate. But if there's anything we should have learned from the past six series, it's to expect the unexpected.