Richard Madden plays Mason Kane, described as “a highly skilled Tier-One agent” in Citadel. The high-octane, highly ambitious spy series from Avengers men Joe and Anthony Russo, which is one of Prime Video’s biggest shows in recent times (the first two episodes will stream from today), has the Scottish actor, who has a very charming accent, using both brain and brawn to play a man with two different identities, with the role demanding both hardcore action and strong emotional drama from him.

Madden, 36, is, of course, not new to big-scale television, having been an integral part, in the role of Robb Stark, of Game of Thrones. On his recent visit to Mumbai, where he and his Citadel co-star and desi girl Priyanka Chopra Jonas, kicked off the promotions of the series, the suave and charming Madden chatted with The Telegraph.

Have you had the chance to see anything of Mumbai yet?

I haven’t been able to go out at all and see the city. I got in about 24 hours ago and all I have seen is many different rooms inside this hotel! (Laughs) I am hoping to go out tonight (crosses his fingers).

Game of Thrones is as big as it gets when it comes to big-scale, event television. Citadel is a global-spanning series which has been made on a humongous budget of $300 million. What makes it different from anything that you have done before?

The one big factor is that I am playing two characters (Mason Kane and Kyle Conroy) in the same body... two very different characters in the same man. I haven’t played anything like that before.

Another factor is the tone of the show, which I find very unique. I haven’t yet come across a show like Citadel which is as invested in the action as it is in the drama and tries to incorporate both in equal measure at the same time. Duality is not just a theme on the show, there is literally duality in terms of its characters.

The themes that we are addressing and the genres that we are playing with are very fresh and unique. That’s what the Russos (Joe and Anthony Russo, the executive producers of Citadel) do so beautifully... they bring in new things all the time.

What does doing a project which the Russos have described as their “most ambitious yet” mean to you?

I always get excited working with people who are passionate, and the Russos have their own unique way of working. They have such a huge vision and with Citadel, they have created something which is not only spanning multiple continents and countries within our own series... on top of that, we have the Indian version (directed by Raj & DK and starring Varun Dhawan and Samantha Ruth Prabhu) which is currently being shot and the Italian version which is already wrapped. Who knows about the other versions which are coming.... The Russo Bros excel in having that sense of scale in their heads and that’s something that’s really inspiring to watch and be part of.

We get to see the high-octane action that you do. Was it also mentally stimulating to be a part of Citadel?

Ya, absolutely! This, for me, is really exciting and hugely challenging. I had no idea how to go about this show and play this character till I started doing it. To be honest, I was initially intimidated by this idea: ‘How am I going to bring about a differentiation between these two men?’ I not only had to work on what’s different between them, but I also had to figure out the similarities between these two men, and that actually became my way into figuring out how to play them. Along the way, I kept realising: ‘Okay, now I have something that I can play with here.’

I am someone who has always been fascinated by the human psyche. Things are built into every human and through this show, we figure out what character traits are inherently built into a person despite their life experiences and what are the things that are learnt and become part of one’s reactive system. Having these parallels between these two characters, without them having any knowledge of each other, was something that was new for me to play with.

Any injuries on set?

Priyanka (Chopra Jonas) has a permanent scar on her forehead and even I did get bashed around and bruised quite a bit. But that comes with the territory once you set out to make something as realistic as Citadel. All part of the job (laughs)!

With his Citadel co-star Priyanka Chopra Jonas

A lot of it must have been in the script, but what did you bring to the character(s)?

What I tried to play with was the tone. This is a very different show. Despite its overall seriousness, sometimes it’s also very funny. There is a lot of action, but it’s also a very intense drama. What I tried to explore was this moral grey zone that lives in all of us, and this element that nothing is ever good or bad exclusively. It’s always a sliding scale. I get to play two characters and slide that scale to two extreme versions.

What I was asked to bring into this was: ‘Okay, how can we create this full-coloured image with as many different paints as we can?’ And then the ability to pull out each different element of the character as and when needed... what is lacking in Kyle is maybe present in over-abundance in Mason. And the trick lay in being able to balance these two things. If there were two separate actors playing these two different characters, you wouldn’t have the same balance. I had to intricately know the two of them inside-out. So by the end of the series, you should get an idea of one whole man, but during it, different elements of the two keep popping up. That was very tricky.

Priyanka and you have repeatedly said that both of you “danced very well together” in terms of your equation on screen. What went into creating that chemistry?

That’s something that we worked on. It’s amazing if actors already have chemistry, which I think we did. But the payoff on screen had to be much more for the audience and that’s the kind of extra work that we put into this equation. As people on the show, we are both in the same boat of having dual characters and wondering how to create them separately and also have them interact with each other. So not only did Priyanka and I have to collaborate and interpret our own characters, but we also had to interpret each other’s characters as well to make this kind of fully-rounded show that Citadel has turned out to be.

From the initial action sequence that you see as soon as the first episode opens, you will realise that these two characters (Mason Kane and Nadia Sinh) are exceptional when they stand alone, but when you put them together, they become a different kind of storm. That’s not something that is present in any script. That’s what the actors collaborate and bring in. They look each other in the eye and say: ‘How do we do this?’

MADDEN MAGIC

Game of Thrones

“All men should keep their word, kings most of all.” These memorable words in Game of Thrones were immortalised by Robb Stark, played by Richard Madden. The eldest son of Lord Eddard Stark of Winterfell and his wife, Lady Catelyn, Robb was an integral part of the initial seasons and made us weep copiously at the Red Wedding when he and his mother were slain.

Bodyguard

The popular British series, in which Madden played a British Army war veteran suffering from PTSD who is now assigned as a police sergeant, won the actor a Golden Globe.

Rocketman

The musical biopic about rock legend Elton John (played by Taron Egerton), had Madden in the part of his former manager and lover, John Reid. The character had a huge influence on Elton’s personal and professional life, with Richard playing him with both showmanship and sincerity. And also a large number of wigs!

1917

Madden brought both heft and heart to the part of Lieutenant Joseph Blake in Sam Mendes’ epic war film. He may have turned up late in the film that won three Oscars but left a deep impact.

Eternals

Eternals may have failed to impress overall, but Madden put in all he had in the part of Ikaris, a superhero who flies like Superman, shoots lasers from his eyes like Superman and also broods like Superman.