The most recent House of the Dragon episode gave new meaning to the term “blood brothers.” In the second episode of House of the Dragon season two, identical twins Ser Arryk and Ser Erryk met their untimely demise after an epic sword fight in Queen Rhaenyra’s bedchamber. In an interview with The New York Times, identical twins Luke and Elliott Tittensor, who played Ser Arryk and Ser Erryk, discuss the great lengths they went to nail the scene and the emotional toll it takes pitting brother against brother.

“There’s a hero’s loyalty and sacrifice, but the downside—I mean to the extreme—is that you’re so blinded to your feelings by your oath and your honor that you’ll kill your own brother,” said Elliott.

While you’d be forgiven for confusing them, it’s Luke who plays Ser Arryk Cargyll, member of the Kingsguard of Aegon II Targaryen (Tom Glynn-Carney), and Elliott who portrays Ser Erryk Cargyll, sworn protector of Queen Rhaenyra Targaryen (Emma D’Arcy). Ser Arryk and Ser Erryk’s divided allegiances come to a head in episode two, when Ser Criston Cole (Fabien Frankel) demands that Ser Arryk infiltrate Dragonstone by impersonating his identical twin and murdering Rhaenyra. Ser Criston’s plan hits a major snag, however, when Ser Arryk is intercepted by his brother, Ser Erryk, in Rhaenyra’s quarters. The two brothers subsequently fight to the death, with Ser Erryk slaying his brother before killing himself.

Although it came as a shock to audiences, the Tittensor brothers were prepared for their characters’ untimely demise. They’re both familiar with most of Fire and Blood, the George R.R. Martin book that serves as the source material for House of the Dragon. “Once we got the job, we researched the material up to the point of our deaths,” Elliott told the Times. But that’s where their House of the Dragon knowledge ends. “We didn’t want to go past that, just because we didn’t want to spoil the rest of the show.”

As for their duel, the brothers rehearsed for more than 30 hours to get it right. “We were very intent on making sure we could do the whole thing and didn’t have to use the team for any shots, because we knew the emotional side was going to pierce through,” said Elliott. “It was just concentrating on making sure that the dance was right.” Luke noted the lumbering quality of both Ser Arryk and Ser Erryk, and how they worked with two of the show’s stunt coordinators, Rowley Irlam and Ben Wright, to have that quality come through in the fight.

“Our swords have knuckle dusters over them, so you can’t really do a lot of fancy twizzles and spins like a really slick swordsman,” Luke added. “That made us think they’re guys who are a bit heavy with their swords, who get up close and personal.” Elliott described the fight as “more realistic” than other battle sequences, and Luke agreed. Their final fight was “a bit rough, a bit dirty, a bit messy,” said Luke. “Rhaenyra is trapped in a cage with two lions trying to take chunks out of each other.”

The deaths of both brothers highlights the senseless violence endemic to Westeros. “Our relationship and our death were very much a symbol—not just of what’s to come, but the theme of the whole piece, really, which is family against family,” said Luke. While they were on opposite sides of the war in Westeros, being actual identical twins made filming the final battle scene easier. “I think it helps,” said Luke of acting opposite his identical twin. “You’re aware of what they’re up against because of all these years of being a twin. If that was a scene between me and Criston Cole, it would probably be a bit harder. Doing it with Elliott made it easier to get there and sit in that head space. It’s naturally grounded, something you can latch onto.”

Elliott went a step further, noting how special it is not only to be a twin but to be identical. “Even a twin who’s not split-embryo…not to sound disrespectful, but they’re more like a brother and sister born at the same time,” he said. “An identical twin is a beautiful phenomenon of nature.”