Warning! This article obviously contains massive spoilers for the final episode of Line Of Duty series five.

For six long weeks, we’ve all been on the edge of our seats waiting to find out  who the mysterious H is in Line Of Duty, and now we have our answer. 

Well, kinda. 

See, Sunday night’s series five finale wasn’t exactly straightforward, as it was revealed that H doesn’t actually exist, and that dastardly legal counsel Gill Biggeloe was framing AC-12 boss Superintendent Ted Hastings as the head of the organised crime group.

Confused? Here’s how it all went down… 

After AC-3’s DCS Carmichael stacked up the mounting evidence against Hastings during tense interrogation scenes, a shock twist saw DS Steve Arnott and DI Fleming turn the tables on Biggeloe after uncovering evidence from late undercover officer John Corbett’s wife.

The AC-12 pair had obtained a recording of a meeting between Biggeloe and Corbett, which took place a full month before the inception of Operating Pear Tree.

It revealed she had informed him about the connection between Hastings and his late birth mother, Anne-Marie McGillis, as she was acting as an informant for the Royal Ulster Constabulary while he was serving in the force during the 1980s (there had even been suspicions Hastings and Anne-Marie were having an affair, although during questioning, he denied ever getting too close to her).

Manipulating his vulnerability by claiming that Hastings was responsible for Anne-Marie’s death, Biggeloe then told Corbett they were setting up an undercover operation to prove Hastings was bent. Making him believe Hastings was H, she encouraged him to put himself forward to act as a UCO on the case, so he could avenge his mother’s death.

From this recording, Hastings was able to deduce she had been recruited by the OCG whilst working as a defence solicitor, and she had been kept on a retainer to fund her taste for the finer things in life, but this had obviously come with certain conditions.

Continuing to reveal the evidence against her, Fleming and Arnott were then able to prove Biggeloe had been using a burner phone in the vicinity of the AC-12 HQ when Hastings was there alone to make it look as if he was making calls on it. It was also revealed she had taken hairs from Hastings’ comb while in his hotel bathroom to plant on Corbett’s body and fit him up for his murder.

It was also uncovered that former DCI Mark Moffatt was also involved in trying to bribe Hastings, using money that came from the OCG disguised as an advance of funds from the Kettle Bell Complex property development. He was later arrested for his part in the case.

After her arrest, Biggeloe tried to stage an ‘urgent exit’ (akin to how The Caddy escaped questioning back in series three), but after no back up arrived to save her, it seemed the OCG decided she wasn’t an asset worth keeping. In fact, it turned out they actually wanted to prevent her from talking further, using bent AC-3 officer PS Tina Tranter to try and stab her to death in the toilet. However, it remained deliberately unclear who gave Tranter the order to kill Biggeloe.

Meanwhile, a rewatch of the dying declaration of DI Matthew ‘Dot’ Cottan (aka The Caddy) revealed that H doesn’t actually exist – H is not an initial of an individual, but a clue.

Fleming and Arnott realised Cottan had been using his hand to communicate in Morse code in the video, which they decoded to reveal there are four police staff (four ‘Dots’) in league with organised crime – Cottan, ACC Derek Hilton, Biggeloe plus one more, who is still at large…

While we later saw DCC Wise and PCC Sindwhani close Operation Pear Tree and cover up its findings to the public, it was revealed Hastings was back at work as the boss of AC-12 – although he had been found guilty of discreditable conduct over his unauthorised undercover operation in episode five, and had been given final written warning.

While Hastings isn’t H, many question marks still hang over his behaviour earlier in the series – especially as to whether he was responsible for blowing Corbett’s cover. Fans were also forced to question his conduct again, after it appeared he had been hiding half the sum of money Moffatt had given him, with Hastings later seen visiting Corbett’s wife at his grave to seemingly gift it to her.

A spokesperson for Line Of Duty confirmed to HuffPost UK that suspicions about Hastings had been left deliberately vague ahead of the sixth series.

Elsewhere, a popular fan theory that OCG member Lisa McQueen was actually an undercover officer was also disproved, when she was given witness protection after sharing information on the OCG, now working to help teens avoid crime.

We also saw OCG member Ryan Pilkington accepting a place on a police training scheme. With McQueen sparing him in the intelligence she shared with police, he is now free to operate from inside the force undetected, setting up a possible storyline for the next series.

So, as you can see, the finale might have wrapped some things up, there were still plenty of loose ends left hanging – take a look at a closer examination of all those unanswered questions here.

Line Of Duty’s fifth series is available to watch again on BBC iPlayer, with the previous four series also on Netflix.