Jessica Henwick, who was born in Britain to a Singaporean-Chinese mother and a British father, joins the cast of Game of Thrones in season five as Nymeria Sand, the second of Prince Oberyn Martell's eight illegitimate daughters. She talks about being the first Asian actress to star in the show and on-screen nudity.

Are you a Game of Thrones fan? "Yes. I was watching the series a year or so ago, thinking, 'I wish I could be on that - but that's not gonna happen.' Now here I am. After the audition, my agent called me at 7pm saying, 'You got the role.' At 7.15pm, I had a call from the production team saying, 'Can you fly out at the crack of dawn tomorrow to start training?' It didn't really hit me until they announced it at Comic Con. My phone started vibrating like crazy with all these messages from random people, so that was pretty cool."

How does it feel to be the first Asian on the show? "It's overwhelming and scary. I hope I can live up to that responsibility. It's hard to be an Asian actress in London; opportunities are [few]. I got lucky and I have to thank my mum, because we saw the poster for auditions for Spirit Warriors [Henwick's debut television show] one day and I signed my brother up. He didn't want to act, though, so they asked if I wanted to and they rewrote the role for me."

Your character in Game of Thrones is portrayed as being beautiful but deadly. Tell us about the visual elements to your role. "The costumes, made by designer Michele Clapton, are incredible. With all the chiffon, gauze, leather and suede, I think the three sisters [Martell's oldest daughters] are going to look amazing. My character, Nymeria, uses an eight-metre bullwhip and that's deadly. It could blind you if you're not careful."

How did you prepare for your role in Game of Thrones? "I had already read the books, so I went back over them, especially the scenes with the Sand Snakes [the name given to Nymeria and her sisters]. The biggest thing was the bullwhip. I did five months of training and I had a lot of dialogue sessions. The whip represents who Nymeria is. It's not about force and strength but precision and balance. Another TV series contacted me recently, asking me to audition for a character that also had a whip. I turned it down. The only character I'll ever use a whip for is Nymeria … or Indiana Jones."

Game of Thrones has a lot of sex and nudity in it. Was that a concern when you auditioned? "When I got the role, it was very clear that there was no nudity in my contract. It's one thing to see it on screen and another to be doing it."

Can you give us some insight into season five? "HBO would murder me if I gave away any secrets. In this season, the three sisters come in with a plot to kill the Lannisters. Obara wants to charge in there and Tyene is not thinking at all. She just wants to prove herself worthy. Nymeria keeps thinking how she can hurt them the way they hurt her."

Tell us about your childhood. "I was always going back and forth between Singapore and the UK. In Singapore, I'd spend the majority of my time at hawker centres because the food there is incredible. I used to go to the Newton hawker centre every other day. Singaporean curry crab, kway teow, Hainanese chicken rice - my best memories of Singapore are eating. The seafood in England is sad. Asian food is amazing. I love a good Milo Dinosaur, bubble tea and things like that."

Season 5 of Game of Thrones will premiere on HBO on Monday at 9am, with an encore that day at 9pm. 

Don't miss the SCMP's season preview on Friday