Mother of god – be warned this story contains Line Of Duty spoilers of the highest order!

The Line Of Duty finale on Sunday night featured the long-awaited reveal of which character was really “H”.

A hunt for “H” in the fifth series of the BBC drama initially saw Hastings being framed, with a twist in the tale then taking the case in a whole new direction.

This meant we had to wait a whole other series to find out which high-ranking officer had been helping to lead a network of corrupt coppers in collusion with the OCG, and on Sunday night viewers finally learned the truth about the so-called “fourth man”.

Yep, despite speculation it was DCS Carmichael or CS Patrick Fairbank, the series six finale revealed it was DSU Ian Buckells all along.

Well… we didn’t see that coming, but then again, that was probably the point.

Speaking the morning after the finale aired, actor Nigel Boyle – who has played Buckells in three series of Line Of Duty – recalled the moment the show’s creator Jed Mercurio revealed his character’s fate.

“We’d had the first four scripts and started filming some of series six when we had to stop due to the first lockdown,” Nigel said.

“When we were about to resume filming, Jed sent me a text saying, ‘Are you free for a chat at some point today? Don’t worry it’s not that call…’. Which I took to mean that I wasn’t going to end up dead! But I was still quite nervous and not sure what he wanted to talk to me about.”

He continued: “[Jed] called me and said, ‘the scripts for the next episodes are going to be sent out imminently and so it’s time to tell you the secret that I’ve been keeping, you’re going to be revealed as someone rather significant…’.”

The revelation left the actor “buzzing with excitement” as, like most of us, he never saw it coming.

“I never suspected it,” he insisted. “Because I know how Jed leads people down the garden path with really good red herrings, so I didn’t really pay too much attention to things like Buckells’ golf clubs etc, but clearly I should have done!

“I’d fully bought into the idea that Buckells was low on competence levels but looking back it all makes sense!”

Nigel added: “I’ve been sitting on [this secret] for a long time! The only person I told was my wife, nobody else, I know how much is at stake! Even if you tell someone you trust with your life, they might tell someone they trust with their life and then suddenly more and more people know!

“When friends have asked me who H is I’ve just said there isn’t an H!”

With the sixth series of Line Of Duty now over, fans are speculating about whether a seventh might be on the cards, and given just how many loose ends the finale left untied, we reckon there’s a fair chance we’ll get one…

All six series of Line Of Duty are now available to watch on the BBC iPlayer.