Being an actor on "Game of Thrones" can require patience. Nikolaj Coster-Waldau spent much of the HBO fantasy epic's second season off-camera, and when we did see him as Jaime Lannister, he was sitting in a cage heckling his jailors. But the Danish actor knew his patience would be rewarded in the third season, when Jaime spent through an even more humbling ordeal while on the road with Gwendoline Christie's Brienne of Tarth. It was among the most satisfying journeys of the third season, highlighted by a hot tub confession that was among the best-acted moments of the series to date.

I spoke with Coster-Waldau last week about Jaime's ups and downs, his working relationship with Christie (and with one of their furry co-stars in season 3), the production logistics of Jaime's new physical condition, and more.

Had you read the books when you took this part or before it? I'm just wondering how much you knew about how much Jaime was going to be changing over the life of the series, including losing his hand.

I didn't know anything about it — I'm not proud of it, but I'd never heard of George R.R. Martin before I was introduced to it. But then I read the first book, of course. And ("Game of Thrones" writer) Brian Cogman, in the beginning, he was kind of the know-it-all, he gave me this very detailed description of Jaime and his whole journey and the whole history of this character, which has been very very helpful. Whenever there are questions, he's the guy you go to, because he has a crazy memory. When I first met him, I didn't know anything, but once I got the part, I dug into it. So I've known all along, and that's been very helpful, because a lot of things happen to the guy. Also, in season 2, there aren't that many scenes, but that whole prison does it — it's not just losing the hand, but it's that he's never been in a situation where he hasn't been in some kind of situation of privilege. He's the worst kind of prisoner, the one that everyone hates. They all want to kill him, and he's basically left to sit in his own shit. I have a feeling they wouldn't go "Do you need a bathroom break now, Kingslayer?" Those things are very important to know what happened, and what he was going through.

How much of the emotional turnaround that we see him go through in this most recent season is simply a result of circumstance, and how much do you think was really inside this guy all along, in terms of the regrets he has about the life he's lived to this point?

A lot of it was all there all along. I just think that sometimes, you meet people — most of us go, 'Why are they still together? Why is this couple still together?' Abusive relationships go on and on. You're in it for so long that it can almost be impossible to see it for what it is. That just becomes your life. We get used to and adapt. There's no question in my mind that the relationship he has with his sister — I'm not talking about the sexual stuff — that's what it is — but the fact that he's given up so much for his love, for a woman who I don't think she feels the same for him as he does for her, they're just very different. The fact that he was finally forced to be away from her and that environment had a lot to do with finally being able to realize who he is. That's one half. The other half is the whole being the Kinglsayer and that whole identity, that he hates more than anything. As we find out, what he thought was in many ways the proudest moment of his life has been turned into this really horrible disgraceful moment.

How do they accomplish the no-hand effect? Is it something low-tech, like hiding it in your sleeve most of the time, or is it significantly more complicated than that?

(laughs) There are quite a few different (methods). I think I have three different prosthetic arms. In the wide shots, when I'm riding the horse, it's just my own arm that I just hide as much as I can. As soon as I get a little closer, we have to go with the prosthetic. There are a couple of different ways to do it. One is I have my own arm down by my crotch or my crack and try to hide it. The last one is the bath house scene where I'm naked, they had to come in and attach a whole arm to my skin, and then I wore a green glove so they could just paint out my own arm. I hear they're working on something magical for next season.

Let's talk about the bath house scene, because you don't ordinarily think of a hot tub as a moment for emotional soul-searching, but you're delivering this great monologue. What do you remember about getting that speech, doing that speech and also having to do this big emotional moment while wearing the fake arm and the green glove?

It was a massive scene on many levels. As I said before, I knew this moment was coming, and it was very important for me. There were a lot of dangers. There's all these visual things, it could become very cheesey, I think, if we didn't do it right. So we were very lucky. Alex Graves, the director of this episode, and Bryan Cogman, who wrote a beautiful adaptation, were very very good at allowing me and Gwen to really have time on set, a few days before we got to shoot it. Not so much actually rehearse the scene as just talking about it, and making sure that all these practical questions are answered: How are we going to shoot the nudity? How naked are we going to be? Where will the camera be? How am I going to have my arm under water? All those things you don't want to think about while you're doing this scene where for the first time ever, he tells someone the truth of what he's been carrying around for so many years. And then when we did it, they were very nice in allowing me to do full takes, which was crazy hard on everyone involved. You do a scene like this, and it's a very long scene, and then you want to do three takes, four takes, and we went way over that period we had to shoot it. It was a very long and hard day, but it was one of the best days I've ever had on a set.

I'm curious about the working relationship between you and Gwen, since she was your main scene partner for this entire season. How did the two of you work together, and did the bond that developed in any way parallel what was going on between Jaime and Brienne?

She is a great, great actress. She has so many good qualities. Work-wise and professionally, she is extremely dedicated, and it's very important for her, even personally, I think she identifies deeply with Brienne and wants to do her justice. It's just great that way that we share this passion for the characters. And we discovered early on that we share the same sense of humor, which is a very — how do you call it? — to most people, we sound as if we're fighting all the time, kind of carrying on the relationship Jaime and Brienne have into the real world. We're having a lot of fun, but we say nasty things to each other all the time.

Like what?

I wish she was here. You could call her up and ask, because she could tell you some horrible things about me pretty quick. It's just a constant. I'm not thinking of one right now, unfortunately. We just have a lot of fun. I'm sure the people working around us are sick and tired of us by now. Maybe it's because the scenes are so serious. This season in particular has been very traumatic on many levels for both characters. She's been nearly raped and killed by a bear. I had my hand chopped off. I think we both, without talking about it, had a need to lighten up between scenes.

You mentioned the bear, so I wanted to ask about when you went to California to shoot the stuff with Bart.

Yes, Bart the Bear the Second. I didn't know there was a First, but he's the Second. It was crazy! Most of the scene was shot with all the extras in Belfast in October of last year, and then we came out in January to shoot with the bear. To be on the set with an animal that size and that smell is quite extraordinary. And to see what the trainers could make him do. It's really surprising.

Now, this is a trained bear, and there are handlers and controlled conditions, but you're jumping into a pit with a giant bear.

(laughs) The way they control it is there's a tiny little wire that goes across between the set and the cameras and the crew. Just a tiny wire. And there's a little battery in the end of it. So if you hit it, you're going to get electrocuted with like 9 volts. That's what keeps the bear in place. If the bear was upset or something, that wouldn't stop him. He would just go. Once they brought Bart out, we all had to stay where we were. You couldn't leave, you couldn't arrive, couldn't eat anything. Everybody had one job, which was one job: we had to cheer and applaud Bart constantly. To make him go onset, we had to go, 'Bart, you're the best! Good boy! That's a good boy!' And as soon as you yell cut, there would be cheers and applause, you could see Bart, he was kind of looking out, sniffing the air, and then they would throw some fish at him. It was amazing.  I think I've only worked with a few actors like that before, but he was one of the biggest divas.

Obviously, the people who have read the books knew already about the transformation you were going to go through this year, but for the fans you encounter who just know you through the show, has that changed a bit now that Jaime's been painted in a more sympathetic light? Or are there people who just can't let go of the fact that you threw Bran out a window?

It's been very interesting. I've had people say that they love the show and like what I do but they hate Jaime because he's so horrible. But now I get a lot of, (American accent), 'I never thought I was gonna say this, but he's a nice guy. He's a good guy!' The funny thing is, what I love about the show is that it's all perspective. One of my favorite lines of the season was Tywin in the last episode where they talk about the Red Wedding, he asks someone to explain why it's morally sounder to kill 10,000 on a battlefield instead of 12 people at a supper. And it's true. But we invested in the Starks, and it's horrible and terrible, and it's a horrifying incident — but if we'd been invested in all these Lannister soldiers on the battlefield, it would have been horrible as well. I just like the way we play with perspective. Jaime, I've never seen him as a bad guy before. Of course his actions have been very brutal, but I've never seen him as a baddie doing something horrible just because he likes it. It's more the fact that we all have the capability within us to do stupid things — horrible things.

Alan Sepinwall may be reached at sepinwall@hitfix.com