When Jamie Kenna got off the phone with his agent following an audition for season two of House of the Dragon, he was devastated. He hadn’t booked the role.

Ser Alfred Broome, who serves as a knight on Queen Rhaenyra’s black council – and, as the British actor describes, is a “Targaryen by employment” – had escaped him. “I was absolutely gutted because I really, desperately wanted it. I thought the audition had gone well,” Kenna tells The Hollywood Reporter.

But three weeks later, casting directors for HBO‘s hit Game of Thrones prequel changed their minds. A week after that, Kenna was in costume and on set, surrounded by fellow castmembers Emma D’Arcy, Matt Smith and Eve Best. Having initially lost out, he came to understand that this was the role of a lifetime.

“I knew it was the biggest, it was the next level that I’d always wanted,” he says. “This is the job I’d been waiting for. While I was so elated when I did get it, I didn’t realize, even then, the scale of [House of the Dragon]. There’s house banners on some of the world’s most iconic buildings, dragons on the Empire State Building. They didn’t do that for Coronation Street.”

Until now, Kenna’s résumé has been a mixture of British soaps, such as Coronation Street, Casualty and Silent Witness, with a few bigger projects like The Crown and His Dark Materials. But Dragonstone is a world away from what he is used to.

A glimpse of what’s to come from Kenna’s character was offered up in episode two, which aired Sunday night. Ser Alfred received a swift telling off from Rhaenys (Best) when he implied Rhaenyra had been responsible for the slaughter of a young boy (who, for Team Green, was also heir to the Iron Throne). It’s a well-established fact Game of Thrones and House of the Dragon fans are accustomed to gruesome stories of bloodshed and murder, but Kenna was integral in keeping things light while filming.

“You’re doing dour, bleak scenes where there’s been the decapitation of a child and then you yell ‘Cut!’ and there’s so much fun and games and messing around,” he says. “There was a lot of laughter, a lot of banter, which is much needed when you’re losing kilos by the hour in that leather armor.” At this moment, his publicist interjects to clarify it was Kenna providing the set with those fun moments, according to lead star D’Arcy.

Despite the huge names around and the monstrous set before him, Kenna wasn’t intimidated. “My first day, I walked on set, and I’m with Matt Smith on the set of Harrenhal – which is mind-boggling, how they build those sets out of wood – and he couldn’t have been friendlier. He couldn’t have been more welcoming. Matt Smith is a very, very generous actor. So the whole experience exceeded expectations… The atmosphere is so friendly,” he adds. “Everyone’s just so happy to be there. It feels like a small job, which is lovely.”

War is brewing in Westeros, and with every episode, the violence is escalating. Kenna can’t reveal too much but promises “excitement, controversy, war and naughtiness – however you interpret that — ” is coming. Ser Alfred gets a story of his own this season. “[Episode two] was a really nice introduction to his manner, to how he feels,” Kenna says. “Because I think even in that tiny little bit, they did a very nice moment where they focused on the guards staring at me and Rhaenys gets me in line. If you watch it again, it sets it up to show that this guy’s not afraid to say something. And that’s very much where the journey goes, with the climax of that in the last episode. No spoilers, but he tries to take things into his own hands a little bit.”

“It’s all a mess,” Kenna says of the looming civil war. “People are trying to grasp control. So [Ser Alfred] very much wants to go in and stamp. He thinks we should be going all guns blazing, sending out messages. He’s a general, so he’s not rash. He wants to build an army, and he wants to do things the right way, in a functional way.”

The chance to fight for the Targaryens is a dream come true for Kenna, who grew up in a working-class family with an ambition to act. He has cherished this experience so much that the House Broome crest is now tattooed on the actor’s leg. “I love being on set. I love actors, I love being around people. I’m lucky to have done some of the most amazing jobs. And I’m riddled with imposter syndrome every time,” he confesses. “[House of the Dragon] was definitely up there, I’m going, ‘What am I doing here? How did I get here?’ And so I’m very positive, I’m very jolly, and I’ll crack lots of jokes.”

But crucially, everyone on this set went along with Kenna’s quips and high-spirited nature. “It’s the best job I’ve ever had.”