Who is H in Line of Duty? Criminal mastermind revealed in season 6 finale

Prior to the season six finale, fan theories regarding the identity of H ran wild, with suspicions cast on almost every character

The finale episode of corrupt copper drama Line of Duty was the BBC’s most watched episode to date as anxious viewers tuned into the find out the identity of the criminal mastermind simply known as H.

This is what you need to know about the major reveal.

Warning: this article contains spoilers for Line of Duty, including the season six finale.

Did you manage to figure out who H was before the big reveal? (Photo: BBC)

Who was revealed as H?

An average of 12.8 million viewers tuned into the finale of the BBC crime drama hoping to finally find out the identity of the mysterious H.

The highly anticipated episode unveiled that DSU Ian Buckells (played by Nigel Boyle) was the criminal mastermind H all along.

The long running H storyline revealed that four corrupt coppers were really part of an undercover crime organisation - DI Matthew ‘Dot’ Cottan (Craig Parkinson), ACC Derek Hilton (Paul Higgins) and Senior Legal Counsel Gill Biggeloe (Polly Walker). It was revealed on Sunday night that DSU Ian Buckells was the missing member.

While the revelation of the identity of H has been met with mixed reviews from fans and television critics alike, there are some that state that the clues had been there all along.

Buckells first appeared in Line of Duty from the beginning, showing up in the first series in 2012. One of his first appearances was on a golf course with the OCG leader Tommy Hunter (Brian McCardie).

In the second episode of the sixth season, there was a scene which lingered on Buckells - and behind him was a picture that depicted the silhouette of a person swinging a golf club in the background. It’s been long apparent to fans that there were strong association between golf and H following the revelation that Cottan was The Caddy, in season three.

Earlier in season six, witness Deborah Devereaux (Kerri McLean) wrongly fingered Terry Boyle (Tommy Jessup) as a suspect in the Gail Vella (Andie Osho) case - it was later revealed that when Devereaux was arrested on suspicion of assault in 2012, the charges were dropped following an intervention by Buckells.

It was DI Kate Fleming (Vicky McClure) who figured out that it was Buckells who instructed Deveraux to falsely identify Boyle. This storyline traces back to season four, when Buckells was shown to receive a text from Deveraux.

It was also Buckells who was responsible for the paperwork error which gave the OCG the opportunity to swap Boyle into Carl Banks’s flat at the beginning of this series.

What has the actor who plays H said?

Taking to Twitter after the finale, Boyle Tweeted: “This is not a pigging joke… neither is it total b***ard b***ocks… but I can finally confirm that I am DEFINATELY…. H.”

Speaking about the reveal, Boyle said: “I was buzzing with excitement! I never suspected it 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!”

Speaking about how he found out the true identity behind his character, Boyle said that show creator Jed Mercurio had revealed the news on a phone call.

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

“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 I wasn’t going to end up dead!

“But I was still quite nervous about what he wanted to talk to me about. He 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 actor said that the only person he filled in on the twist was his wife, Lainy.

Boyle said: “I’ve been sitting on it 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.”

Will there be a season seven?

As it stands, a seventh season of the show has not yet been given the green light by the higher ups.

Speaking to Radio Times in March, show creator Jed Mercurio said: “We’re in a situation where it’s not entirely clear that there will be a seventh series.

“We would hope there could be. But we’re having to do our planning coming out of Covid, and a whole bunch of other things around the idea that these things aren’t guaranteed at all now.”

Mercurio added: “Since probably season four, we’ve been talking to the BBC about the realistic longevity of the series. I’ve experienced broadcasters pulling the pug while we were still developing a storyline - Bodies and Cardiac Arrest both ended prematurely on the BBC.

“So it’s an ongoing discussion, is all I can say. A lot of it depends on the key creatives - me and the main actors - finding new stories to tell within that universe.”

However, Line of Duty fans shouldn’t panic yet, as it does sound promising that another season could be on its way.

“Without a formal commission, I would say conversations have been very reassuring from the standpoint of not having to wrap things up,” Mercurio said.

Appearing on The Jonathan Ross Show, Martin Compston, who plays DI Steve Arnott, said that the show wouldn’t return “just for the sake of it”, and that it would lie in the hands of show creator Mercurio.

He said: “That’s nothing different for us. Jed always takes months after… there’s stuff above our pay grade, analytics, figures and all that kind of thing that comes in.

“He always takes time off. But I think it is important to say, I think this natural story arc that we’ve been on for the last six year [is coming to an end].

“We won’t come back just for the sake of it. That’s for sure. We’ll come back if there’s a story to tell. But, so as well, if it ends well maybe sometimes it is best to leave it. But, we genuinely don’t know.”

The BBC has suggested that it would be more than happy for the show to continue, should Mercurio wish to make more episodes.

BBC Chief Content Officer Charlotte Moore said: “I’m looking forward to having a conversation with the team about where we go next and what the future of the series might be.”