Martin Compston, Adrian Dunbar and Vicky McClure star in Line of Duty, streaming on Acorn TV. Photo: Supplied
His biggest shows have more twists than a Chubby Checker retrospective, but in real life Jed Mercurio won't leave you guessing.
The brains behind Line of Duty and Bodyguard is frank about his inspiration for the TV juggernauts: institutions failing to front when they stuff up.
"I think anybody nowgoing through life bumps up against the great bureaucracy and self-protection of a lot of the institutions we have here in the UK, and it's the same the world over.
"What you'll often see is, rather than being open and trying to learn lessons and apologise and compensate people they've harmed, they close ranks, and they evade and obfuscate. And they try and avoid accountability.
"No one's expecting them to be robots who get everything right constantly, but it's how the institution handles that and, to a certain extent, that was the inspiration for Line of Duty."
Mercurio - early 50s, married father of two, arguably the most powerful creator of TV drama in the UK - is on the phone from his home in London.
Friendly, thoughtful and, unsurprisingly, precise in dialogue, he's promoting the arrival of the fifth and latest series of Line of Duty on Acorn TV, a boutique streaming platform specialising in UK drama.
For newcomers, the show's about a fictional police unit that tackles corruption in the force. As series five rams home, boss Ted Hastings (Adrian Dunbar) and his sidekicks Kate Fleming (Vicky McClure) and Steve Arnott (Martin Compston) face a sprawling crime network with many cops in its pocket.
Existing fans won't be disappointed: present and correct are the usual gripping interview scenes, brilliant guest stars, shocking deaths and labyrinthine plotting.
A major storyline is a cloud of suspicion over Hastings, a character with enough catchphrases to inspire a drinking game among fans.
"People are interested in the characters and it makes them speculate about maybe what secrets they hold, even if they've got very little to go on. It seems that you don't need to do very much with the character of Hastings for speculation to run riot."
Mercurio's frustrations with institutions stem from his time as a doctor in the UK's public health service. That job informed two early hits, medical dramas Cardiac Arrest (written in the mid-1990s under a pseudonym while he was still practising) and Bodies.
Bodyguard is his biggest success. About the tribulations of a police protection officer (Richard Madden) assigned to a Government Minister (Keeley Hawes), it was a cultural phenomenon when broadcast in the UK in 2018.
The series gave the BBC its biggest audience for a decade, with the finale watched by 17 million people, almost a third of the population.
Success on that scale must create pressure.
"I certainly don't regard it as pressure," says Mercurio, "the reason being that I've had my ups and downs in my career over the years. And pressure actually comes when something isn't performing well."
Filming on series six of Line of Duty was already under way when Covid-19 intervened and production ceased.
Unsure when it will resume, Mercurio has already spoken of possible reshoots. The shutdown has also delayed decisions about another series of Bodyguard.
Frank in conversation, he's forthright on social media too. Blunt with trolls, and sometimes journalists, he's a frequent critic of the UK Government's response to the pandemic.
"Like a lot of people, I've seen the way in which it has been mishandled here and a lot of the influence for my opinion comes from reading the views of experts.
"I've read the analyses that have been coming out of various departments of public health, and now we have an independent scientific advisory group who are very transparent.
"The Government has hidden behind saying that they followed the science. But It's pretty clear something has gone very wrong in terms of the relationship between scientific advice and public health policy and, I think, with unfortunately tragic consequences."
Despite the shutdown, Mercurio has much to do.
Beyond posting Line of Duty bloopers and skits on social media to support an appeal buying equipment to protect frontline UK medical staff from Covid-19, he co-owns a newish production company. It's already commissioned highly anticipated dramas starring Line of Duty's McClure and James Nesbitt (Cold Feet).
"I still really enjoy my writing. I'm still very intent on developing new projects for myself and writing for the next few years. It's just a diversification into being able to work on projects that I wouldn't be able to write or I wouldn't be the right person to write, and to work with really talented people on helping get those works on screen."
And with that he's off for another interview. Duty calls.
LOWDOWN Who: Jed Mercurio What: Creator of premium British dramas Line of Duty and Bodyguard. When: Line of Duty series 1-5 are on Acorn TV. Bodyguard is on TVNZ from Monday.