Charming and urbane though he is, talking to Nikolaj Coster-Waldau about the highly anticipated third season of Game of Thrones turns out to be frustrating. And not just for us but for the 42-year-old Dane as well, who constantly has to bite his tongue in case he lets slip some tantalising spoiler about what shocks are in store for his character, the sinister yet charismatic Jaime Lannister, in HBO's acclaimed adaptation of George R.R. Martin's bestselling A Song of Fire and Ice novels.
"Let get this out of the way, I can say nothing really," he laughs. "But what I can say is that when we started with the first series and we had the whole story of the A Song of Fire and Ice books before us, I was hoping and praying that that we'd make it as far as season three. When I first reading the scripts and saw what they're going to do with it, I couldn't believe it. So it's going to be interesting to see what people think of it as it was really exciting to shoot it."
Certainly after being chained to a post for the majority of the second season, Jaime can't help but play a more significant role in season three as he and his captor, Gwendoline Christie's hard-bitten knight Brienne of Tarth, make their way towards Winterfell. "That's where he is when we meet him and then things happen," says Coster-Waldau. "He's still having fun tormenting her, which is one of the things that I like about him. He's very capable with his sword and he's a good soldier but he's even more effective with his words as he knows how to find people's weaknesses. He did that with Catelyn Stark and used it to his advantage. Now he's trying to do that with Brienne and although he seems to be joking, there's always a purpose to what he does."
Having pushed Ned Stark's young son Bran out of a tower in season one's opening episode and sired a child, the Caligula-esque King Joffrey, with his sister Cersei, Jaime would appear to be truly beyond redemption. However, Coster-Waldau begs to differ. "Like all of us, you must have had a moment in your life where you did something that you're really not proud of," he reasons. "If the movie of your life was to start right there, people would think that you're really horrible but that wouldn't be the truth or the whole story. What's great about telling a story like this, where we potentially have 60 hours to do it, is that you can really explore the characters and learn things about them. The initial response to Jamie might not have been good but then more colours have been added to that. One of my favourite TV shows right now is Breaking Bad and they kind of do that the other way around as you start off with this guy who is like the sweetest and gentlest person ever and then he slowly turns into Scarface, which is equally horrific."
Coster-Waldau believes that the compromising situation that Jaime found himself in during season two will ultimately only make him stronger.
"The fact that he was taken prisoner and taken out of his comfort zone was something new for him," he says. "I don't think he had ever been that vulnerable before and that does affect him, as he hates it.
"But I think everything affects us as people. He fell in love with the wrong woman at a very early age and that has kind of defined his life up till now. But change is a part of all our lives and it's also a part of Jaime's life."
Since graduating from Denmark's National Theatre School 20 years ago this year, Coster-Waldau has worked steadily in numerous films and television series including Blackhawk Down and Wimbledon. "I've always been able to support my family," he says.
"Even if Game of Thrones hadn't come along, I would still be doing something."
But thanks to Jaime Lannister, his profile has never been higher and it will grow even more next month when he appears alongside Tom Cruise and Olga Kurylenko in Tron director Joseph Kosinki's new sci-fi thriller, Oblivion. However, he is as reticent about that film's secrets as he is about Game of Throne's future plot-twists.
"I got a memo for doing press which was basically not to say anything about my character," says Coster-Waldau, throwing his hands in the air. "I guess people will just have to go see it."
The third season of Game of Thrones begins on Sky's SoHo channel on April 1.