Vicky McClure admits that, when she got the call about new Amazon Prime series Alex Rider, she'd never heard of the eponymous character before. Originally created by British novelist Anthony Horowitz, Alex is an ordinary teenage boy who is unwittingly dragged into the dangerous and morally compromised world of international espionage.
The Nottingham-born star (37) decided to ask her 12-year-old nephew if he knew about it. "I basically got the response of, 'Yeah, course I know Alex Rider'," she recalls, chuckling.
"So, I felt very uncool. And then felt, 'Well, how cool would it be if I was in it?' He was a massive part of me taking the job on, because a lot of my work is quite adult-based drama, so people like my nephews can't even watch it.
"And then, when I read the script, I just went, 'Absolutely'. It was jam-packed full of loads of different characters, action, genuine emotions and relationships."
In the eight-part series, which has been adapted from the books by screenwriter Guy Burt, McClure - known for shows such as Line Of Duty and This Is England - plays Mrs Jones, the deputy head of MI6, who becomes Alex's professional guardian.
Otto Farrant (23) takes on the role of the protagonist who, after discovering his uncle and guardian, Ian, was an agent for the British Secret Service and died at the hands of an unknown assassin, realises everything that about his family and past is a lie.
Blackmailed into working for the Department, Alex is given a cover identity as the son of a billionaire and thrust into the terrifying world of Point Blanc Academy - a school for off-the-rails teenagers located in the remote French Alps.
"I read the books when I was a kid," says Farrant. "I loved Alex Rider, because he's such a relatable character in that he is just a normal kid who is thrown into this world of espionage and has to adapt super-quickly.
"I was thrown into the same kind of situation; I'd never done anything nearly as big as this, or as intense. I just had to rise to it."
Part of the appeal of the series for McClure was that Mrs Jones is such a strong female character.
"I have been very, very lucky," says McClure. "It's been nice not to continually play the love interest, or the sort of obvious roles.
"We've all read scripts before and thought, 'Well, why can't I play his role? Why can't they just turn that character into a female and turn that character into a male? It would make no difference. I guess people are just starting to change their mindset now."
As the biggest job he has had yet, what did Farrant find was the most challenging moment during filming? "I just had to have stamina. The director said to me at the beginning of this, 'This is a marathon, it's not a sprint' and that was very clear to me after two weeks - I was so exhausted.
"The thing is, your body and your mind adjusts to it, so you rise to it. But there were definitely moments where I had to take a moment just to check myself and just rest."
I suggest he should turn to McClure for advice on keeping secrets. As one of the main stars of the twisty Line Of Duty, she has to deal with constant questions about fan theories and what writer Jed Mercurio has in store. She laughs at this. "You just keep your mouth shut."
While the UK has been in lockdown during the Covid-19 pandemic, there have been a couple of short videos written by Mercurio - starring McClure and her Line Of Duty co-stars Martin Compston and Adrian Dunbar - shared on Twitter.
The idea of the sketches was to raise money for charity Asks For Masks, whose aim is to get PPE to people working on the frontline. And the actress says: "It's been nice to go to work, for all of a minute.
"It's great that we're doing it for a great cause, but when Jed sends through a sort of mini script of Line Of Duty in lockdown and it says, 'Vicky wears a onesie', who am I to complain?" quips McClure.
"I made myself a brew and I'm ready to shoot, which is not how I normally work. It's the dream."
Filming of series six of the police drama was halted back in March, because of the widespread coronavirus outbreak.
And McClure hasn't heard anything yet about when they might return to set, noting that it's "very difficult to shoot in a bubble".
"There will be a lot they need to work out before we can get back to work," she suggests. "So, we will just sit tight."