Line Of Duty: 'My favourite thing is reading the wild fan theories'

**Warning: This article contains spoilers for season six of Line of Duty**

Who is H? Is Ted Hastings a bent copper? Where does Steve Arnott get his waistcoats from?

Line of Duty has once again thrown up as many questions as it's answered - but things do seem to be coming to a head with the series six finale.

Martin Compston, who plays DI Steve Arnott, says the cast and crew are "chuffed to bits" with the show's huge audience ratings.

"We're more popular than ever and seem to be getting in more and more fans the longer this goes on," he tells Radio 1 Newsbeat.

We had a chat with the actor but - as you'd expect - he couldn't tell us anything about the plot. So, we got him to share some behind-the-scenes stories from the cast and crew.

Martin reveals he, Vicky McClure (Kate Fleming), Adrian Dunbar (Ted Hastings) and the show's creator Jed Mercurio get together "for a few wines" every Friday night on Zoom.

"We just talk everything over," says Martin.

"One of my favourite things is reading all the fan theories. There are some absolutely wild ones.

"I saw someone had put together an acronym of something Jimmy Lakewell (one of the show's characters) had said, and that led to the word 'Carmichael' (Patricia Carmichael - played by Anna Maxwell Martin). You just wonder who's got time to sit there and come up with these things."

Even though he's not confirming any theories specifically, he says some of the guesses and ideas online "are pretty on the money" ahead of the finale.

Off-screen, he says the three main actors are genuinely "pals for life" although he does admit he and Vicky descend "into being 12-year-olds by giggling and annoying Adrian" on-set.

The intense, methodical interrogation scenes are a staple of every Line of Duty series and Martin compares them to "short plays".

They're filmed - unbroken - in one take, so if something goes wrong then it's back to the start.

The most recent episode featured the interrogation of DCI Joanne Davidson, played by Kelly MacDonald, and lasted 30 minutes on screen.

"As the lowest ranking detective on screen, I'm the one who's got to drive the scene and present all the information," says Martin.

"So I've got to come up with all these random acronyms and legislations and telemetry. The dialogue is challenging."

The only time he gets to figure out what's next is when "Adrian (Ted Hastings) is on one of his big rants so I can take a wee look at my notes and do some mental gymnastics".

He also knew Ted's "Joseph, Mary and the wee donkey" line from episode six would be an instant classic from the moment they filmed it.

Inevitably, the question he's asked most by his mates is 'who's H?' but Martin says they immediately follow it with "don't tell me".

It's all right to admit if you sometimes get a bit behind with the plot of Line of Duty. Long forgotten characters are brought back from the past and twists can sometimes double back on themselves to leave you a bit tangled.

That even happens to the cast - but Martin is happy to admit he is the "anal" one who Vicky McClure and Adrian Dunbar come to if they have questions about the plot.

"I'm pretty in-depth and need to go over everything."

He puts his attention to the fact he stays in Steve's English accent when he's not filming.

He'll often go "over and over and over" the scripts to make sure he knows it without even thinking. That means he can concentrate on his voice and avoid slipping into his native Scottish accent.

As a die-hard Scotland football fan, 12 November 2020 is a date Martin will always remember as it's the day his team made it the finals of Euro 2021.

The only problem? He was filming - and the match ran over.

"We were on a night shoot filming some raids. Our base was a pub where they set up the football and they gave me until 10pm to watch it before we had to start filming."

Scotland were playing Serbia, who equalised in the final minute, leading to a penalty shoot-out.

"I had to leave the bar and the only access I had to it was the radio in Steve Arnott's car. I was pleading with the crew to just give me two minutes as the penalties were taking so long."

Scotland won and Martin went wild: "It was just 20 years of relief at that moment."

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