taffordshire-raised Jed Mercurio is a former RAF officer and hospital doctor. He answered an ad in the British Medical Journal for an adviser on a TV show and ended up writing the acclaimed BBC drama Cardiac Arrest. He promptly retired from medicine to pursue a full-time writing career, with TV credits including Bodies and Bodyguard. He’s the creator of the hit police thriller Line of Duty, which is filming its sixth series. How is shooting going on Line of Duty’s next series? Really well. I’ve just walked out of the AC-12 interview room, actually. It was one of those scenes where I marvel at our cast as they somehow do a half-hour take word-perfect. Who was being interrogated by whom? Ha. I know what’ll happen if I tell you anything. There’ll be articles all over the internet: “Jed Mercurio reveals Line of Duty season six spoilers!” And then the rest of the piece will be filled with fan theories ripped off Twitter. What can you tell us about the team’s latest adversary, played by Kelly Macdonald? Kelly plays DCI Joanne Davidson, who’s a senior officer on the murder investigation team in our fictional police force. While leading the inquiry into a high-profile unsolved murder, some of her actions arouse the suspicion of AC-12. She’s probably the most enigmatic guest lead we’ve had. Kelly’s just fantastic. She’s great on set, really well prepared and really pushes herself. Are there surprise comeback characters? Little Ryan? Balaclava Man, perhaps? Maybe! Wait and see. There’s no such thing as Balaclava Man, of course. It’s Balaclava Men, plural. Are there any storylines inspired by real-life events this time around? That’s not possible, because police corruption doesn’t exist in the real world. That’s what [former Metropolitan police commissioner] Cressida Dick says, so who am I to argue? Supt Ted Hastings, played by Adrian Dunbar, has become known for his colloquialisms. Does that continue in the new series? Oh yeah, that I can confirm. He does a beaut in the scene we’re currently shooting. I’d written one, but Adrian took it a step further and it made me burst out laughing. Is it true they’re often inspired by Adrian Dunbar’s father? Some of them are inspired by my dad, too. He was Italian, but he picked up idiomatic English when he settled in Lancashire and worked as a coalminer. They’re the kind of expressions that a lot of working men said, then Adrian adds in regional Northern Irish phrases. I’d never heard “I didn’t float up the Lagan in a bubble” before we did a screening of series four in Belfast. During the Q&A session afterwards, just for amusement, I said the audience should call out idioms and I’d put the best one in series five. “Floating up the Lagan” was the clear winner. You’re teaching screenwriting on the new online education service BBC Maestro. What made you want to take part? I’m often invited to speak at writing courses or do Q&As, but they tend not to be terribly detailed. Here we can get into much more depth. There are 28 lessons, covering all aspects of the writing process – but also, crucially, career development. I hope it will offer practical help to people trying to break into TV. There’s a thriving industry out there of script gurus and writing courses, but very few of them have been involved in an actual production. They know the theory but can’t contextualise it with first-hand knowledge. I can. Do we need more diverse writing talent to break through? I’d love to see new voices but the economic realities are harsh. You don’t necessarily earn much money to begin with, so it’s like taking a jump off a cliff. I had to get a full-time job when I left school. People from privileged backgrounds don’t have to worry about that. Their parents can pay the bills while they develop their careers. Sadly, those without that financial support can struggle. You can’t even get grants to get into drama school. Line of Duty stars Martin Compston and Vicky McClure didn’t go to drama school, did they? Exactly. Vicky actually won a place but couldn’t afford to go. She was a part-time actress for most of her 20s. She did an office job but her employers were understanding enough to give her time off for auditions. That’s the reality for working-class people. Most of them give up and drift away. I’m very glad Vicky didn’t. You made your debut appearance on Question Time this summer. How was that? Good, actually. The main subject was the pandemic, which I felt qualified to have an opinion about. I got the sense that you were biting your tongue at times… You have to be careful how you express yourself – make constructive points and stick to the facts. If you start expressing emotional frustrations with the ineptitude, evasions and even mendacity that you’re facing, it’s easy for those things to become noisy clips. So I set out to be as measured as I could. To be honest, it was a triumph of self-control. You’re executive-producing a new drama about Stephen Lawrence. What can you tell us about that? It’s a three-part miniseries called Stephen, charting the Lawrence family’s long quest for justice and their relationship with the Metropolitan police as they tried to secure convictions. What else is in the pipeline? I co-founded a production company called HTM and our first commission is Bloodlands, a detective drama which we’ve shot in Northern Ireland. It’s written by Chris Brandon, who’s an exciting new talent, and stars Jimmy Nesbitt. That airs on BBC One early next year. Later in 2021, we have bomb-disposal thriller Trigger Point for ITV. Vicky [McClure] stars and it’s written by Daniel Brierley, who I mentored through a ScreenSkills bursary scheme. Will Bodyguard return for a second series at some point? Well, apparently, if you read the websites of certain major newspapers, there’s some sort of announcement every week. But when you read the article, you realise they have no factual content whatsoever. You use Twitter as a right of reply to such speculation – quite robustly sometimes! Is social media useful in that way? There’s a bit of a feeding frenzy around certain programmes. Having the opportunity to publicly correct misleading pieces is extremely helpful. If someone’s made an honest mistake, that’s fine. If someone’s being a piece of shit, then you need to just call them all out.