Warning: Very big Line of Duty spoilers ahead
Last night saw the long-awaited finale of season six of Line of Duty.
And while it divided fans, with some left feeling 'disappointed' by how things were left, the show's creator has revealed why he chose Detective Superintendent Ian Buckells to be 'H' or the 'Fourth Man'.
Speaking on the Obsessed With... Line Of Duty podcast, the writer discussed his reasoning behind choosing the bumbling idiot to be the lynchpin in the criminal web that stretched to the heart of the police.
He said: "I suppose it was really down to the decision to kind of hold him to account, sort of mid season.
"You know there were suspicions around him in the first two episodes and then Jo points the finger at him, AC-12 get him in, they charge him, off he goes to prison, and it feels like he's done and dusted.
"And I think that if we kept him as part of the action, all the way through, then it would have been very hard to misdirect the audience, so we were trying to present other candidates to take the focus away from him.
"But it was always really important to me that it was someone who had been in season one, someone who had been there the whole time.
"We did introduce some characters late, so Thurwell came in late, we went back to Fairbank, who'd appeared in season three, we had the Chief Constable, who had obviously been there since season one.
"But then I don't think he would have been a satisfying candidate because he had been absent for so long, it would feel like we'd just brought him back in to pin it on him."
He added: "Also because I think we'd been directing the audience towards a particular image of the kind of character that 'H' would be, that 'H' would be a criminal mastermind, and we wanted to make different commentary on the way in which someone can do a lot of harm without necessarily being a mastermind."
When asked about how so many different characters were set up as potentially being 'H', Mercurio said while characters like DCS Patricia Carmichael and DCI Marcus Thurwell fit the bill in some ways, in others they didn't.
He said: "It was really about the heritage of the series, going all the way back to season one, where Dot Cottan says, 'Oh, can I just have a quick word with Tommy Hunter in the back of the van?' and Buckells goes, 'Yeah, alright'. OK, like, really, is that what you should be doing? Of course, not.
"And so you think he's just a bit rubbish and so he doesn't care. And that ended up being part of the evolution of the character, ya know, when he reveals his story, it's the fact that his personal standards were low, that he wasn't committed to honesty and integrity, and that then made him someone who was vulnerable to being groomed by the OCG into being a fixer for them."
During an interview with the OG AC-12 trio in last night's episode, Buckells confessed that he had worked as a facilitator for different gangs after Tommy Hunter's death and the break-up of the original OCG.
Some fans, however, were less than impressed with how it all unfolded.
Comparing it to the finale of Game of Thrones, one fan said: "Line of Duty ending has joined Game Of Thrones and How I Met Your Mother."
Not everyone was left so bereft, though, there were some who understood where Mercurio was coming from.
"The problem with the #LineOfDuty finale was not that Buckells was the (latest) fourth man. That's a great nod to Arendt's 'banality of evil' and a warning against indifference to corruption," praised one viewer.Featured Image Credit: PA