Line of Duty's Martin Compston hints season 7 will answer unresolved questions

Naturally, Martin Compston is sworn to secrecy when it comes to Line of Duty, which will begin filming in spring 2026 for its long-awaited seventh season.

"Everything is so under wraps," he told RadioTimes.com of reprising the role of Steve Arnott alongside Vicky McClure as Kate Fleming and Adrian Dunbar as Ted Hastings.

They are now working for the Inspectorate of Police Standards after AC-12 was disbanded – but "anticorruption work has never been more difficult" as they are "assigned their most sensitive case so far".

"Detective Inspector Dominic Gough, a charismatic officer winning plaudits for a string of takedowns of organised crime, is accused of abusing his position of trust to act as a sexual predator," reads the official synopsis. "But is Gough’s case a deliberate distraction from a bigger threat still operating in the shadows?"

Compston did say, however, that questions left hanging after the season 6 finale – which drew an astonishing 12.8 million viewers on the night (a 56.2 per cent share) – will likely be addressed.

"There's a new, strong storyline with new characters, and then... there will be things getting answered from other series," he added.

But Compston remained tight-lipped on which plot points have been revisited by creator, writer and executive producer Jed Mercurio, who "couldn’t be more delighted to be returning".

"Corruption in this country is supposed to have come to an end while Line of Duty was off air so I’ve been forced to use my imagination," he joked following the season 7 renewal announcement.

We've broken down all of the major remaining questions here, including why Hastings really misspelled "definitely" as "definately", which was key in unmasking Buckells – a reveal actor Nigel Boyle was initially "gobsmacked" by, assuming the now former detective superintendent was just a "useful idiot".

But "a rotten apple needn’t always be a mastermind", he said at the time. "You don’t have to be a criminal genius to be bent. It can just be gross incompetence and people turning a blind eye.

"I always saw Buckells as the comic relief, so it’s clever that it was him all along. When you reflect and rewatch, I think it's a stroke of genius. Looking back, it all fits" – although many remain unconvinced that Buckells is actually H, with the real mastermind still at large.

So, a shiny new narrative awaits – but if Line of Duty is to be a roaring success, Mercurio must revisit those key loose ends, lest the whole thing unravels.

Read more:

• So, what should we expect from Line of Duty season 7? I have some questions
• Line of Duty could be entering its #MeToo era – but let's hope it doesn't waste the opportunity

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Line of Duty seasons 1-6 are available to stream on BBC iPlayer.

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