Who is H in Line of Duty? The clues were there the entire time

They date back as early as season one

The reveal of “H” in the Line of Duty finale has been teased ever since the first series.

Jed Mercurio’s crime drama drew to a close on Sunday night (2 May), with many viewers left wondering if it will return for more episodes.

Regardless, the show’s long-running “H” storyline, in which four corrupt coppers were revealed to be part of an undercover syndicate, is now over, with the enigmatic “fourth man” unveiled in episode seven.

*Spoilers follow – you have been warned*

The only members known to date were DI Matthew “Dot” Cottan (Craig Parkinson), ACC Derek Hilton (Paul Higgins) and Senior Legal Counsel Gill Biggeloe (Polly Walker).

It turns out that the blundering Detective Superintendent Ian Buckells (Nigel Boyle) was the missing member, a revelation that has left viewers feeling supremely underwhelmed.

However, for all the tweets about how “disappointing” and “boring” this plot twist was, there is a contingent of fans who have been pointing out the fact that Buckells was hiding in plain sight the entire time.

Despite clearly not having the respect of those around him, Buckells was shown this series to have risen through the ranks to become Detective Superintendent at Hillside Lane Police Station, overseeing the MIT unit that was investigated by AC-12.

Long-time viewers may forget that Boyle first played Buckells back in the very first series in 2012. In fact, one of his first ever appearances was on a golf course with the Organised Crime Gang leader Tommy Hunter (Brian McCardie).

Ian Buckells in the first ever series of ‘Line of Duty’ (BBC )

Fans were reminded of this in the sixth series’ second episode when the camera lingered on Buckells, and a painting depicting the silhouette of a person swinging a golf club could be seen in the background.

It’s long been known that the hobby of golf had strong ties to “H” thanks to Cottan, who was revealed in series three to be “The Caddy”.

Superintendent Ian Buckells (Nigel Boyle) and the golf club artwork (BBC)

Also earlier in this series, a witness named Deborah Devereaux (Kerri McLean) falsely identified 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 the intervention of none other than Buckells, which placed her in his debt.

DI Kate Fleming (Vicky Mcclure) then deduced that it was Buckells who asked Devereaux to wrongly identify Boyle.

This development was set up as early as series four, which starred Thandiwe Newton, when Buckells was shown to receive a text from Devereaux.

Nigel Boyle as Buckells in ‘Line of Duty’ (BBC iPlayer)

Moreover, it was Buckells who was responsible for the paperwork error that gave the OCG an unobserved window in which to swap Boyle into Carl Banks’s flat at the start of this series.

There is also the rather brazen hiring of PC Ryan Pilkington (Gregory Piper), which, according to Joanne Davidson, came at the request of Buckells.

As Superintendent Ted Hastings (Adrian Dunbar) put it in the final AC-12 interrogation scene: “Your corruption was mistaken for incompetence."

Buckells actor Boyle has jumped to the show’s defence amid the viewer backlash, telling BBC Breakfast: “You can’t have every series end with a big shoot out.”

Find all the talking points from the finale here as well as all of the show’s unanswered questions here.

All six series of Line of Duty are available to stream on BBC iPlayer.