Nikolaj Coster-Waldau breaks down the always-complicated Jaime Lannister and his decision to return to King’s Landing to be with Cersei.

HBO: Jaime seems to have a potential happy ending with Brienne. How do you feel about his decision to leave her?

Nikolaj Coster-Waldau: In a different world, Jaime would’ve stayed with Brienne. What he has with Brienne is something different — it’s a very pure, innocent love. There is a part of him that wishes he could not be who he is. It’s one of those things we do in Game of Thrones. You have this idea of what you want these characters to do — it’s supposed to end well for these two, they’ve been through so much together — but that’s not how it goes. The most extreme of all these scenes is a couple seasons back, when Myrcella tells Jaime she knows he’s her father and she’s glad he is. He has this moment of happiness, and then the second after she dies in his arms.

Gwendoline [Christie, who plays Brienne] was so moving in that scene. She did an amazing job of conveying that Brienne had finally found happiness she’s never had, and it’s just taken away from her in a brutal way. It’s very true to who these characters are. His staying in Winterfell is unrealistic. Cersei is the most important person in his life, whether he wants her to be or not. The idea that he was going to just let her die alone, is too horrible for him. He asks Brienne: “Have you ever walked away from a fight?” There’s no option for him, he has to go to Cersei. Ramsay Bolton said it best: “If you think this has a happy ending, you haven’t been paying attention.”

HBO: Is there a turning point for Jaime where he decides to return to Cersei?

Nikolaj Coster-Waldau: Bronn appears and Jaime realizes he was sent there by Cersei to kill him and Tyrion — it’s this strange reality check. Cersei has a way of making sure you don’t forget about her. That act is such an extreme thing. I don’t think Jaime believes Bronn is going to kill them; because Bronn is a businessman.

Then Sansa says, “I always wanted to be there when they execute your sister.” He knows that Cersei’s provoked Daenerys so much, and she’s underestimated her enemy — usually Cersei’s the one people underestimate. His whole life has been about trying to protect Cersei, and trying to be close to her. He loves her — it's unconditional love, it’s so ingrained in him. Jaime and Bronn were together when the Lannister army was attacked by the dragons — they saw first hand what Dany can do. If you go against dragons you are going to die.