Walsh's play, which was adapted into the 2001 film of the same name, is about two teenagers nicknamed Pig and Runt, who have a lifelong, but unhealthy, friendship.

By the time you were cast as Luna you were already a fan of the “Potter” books. What did you love most about the books?
Evanna Lynch: I just loved it because it really felt like I understood the people ― the teenagers. I just felt like they were my friends. I loved that it was just like a bunch of misfits, and they were the heroes of the story. And I’d never read a book series before where the characters were so relatable, and inspiring in how relatable they were. I felt what they were doing, and what they were grappling with. The books just had this amazing ability to make me feel not alone. And I think I went through most of primary school and high school just feeling like I hadn’t really met my people, and “Harry Potter” felt like my people. They were the kind of friends I wanted to have.

Of course it was also a more fascinating world than what I was involved in. It just made me believe in things that were different.

I actually read Prisoner of Azkaban around Christmastime. I had a craving for it; I don’t know why. I often do press events and conventions, and I get asked a lot of questions. It was a point of pride that I was like a walking encyclopedia for the books. And I realized my trivia had been slipping the last few years. I was like, oh, this can’t fall away. This is something I need to maintain.

It’s just me being a nerd. The books almost have a resetting effect on me. They bring me back to who I am. And the films are sort of different because it became a career, and it’s so entwined with who I am as a public figure, which I don’t want to think about when I’m reading. The books still remind me of who I am.

Do you have a favorite “Potter” character besides Luna?
Evanna Lynch: I always liked Dumbledore because he’s so wise, and he’s got such a deep mind and thinks so deeply on things, but he’s also able to enjoy the finer things in life. I like that.

And then recently I realized I really like [Gilderoy] Lockhart. I sort of admire that obliviousness he has. He doesn’t seem to be aware of what people think of him, or that not everyone wants his autograph. I think I’m probably too self-conscious. Not in an insecure way, but I have this paranoid thing where I’ll often think people are giving me a weird look or something. My best friend always points it out, he’s like, really, it’s not about you. […] My mind makes up weird stories, and I started to really love Lockhart for how he doesn’t do that. He does the opposite. He assumes everyone loves him. I just think it’s so funny.

What would you say you’re looking for most in acting roles going forward?
Evanna Lynch: Bold characters. I always look up to people who are very unapologetic. Whether their morals are in line with mine ― say for example, the character in “Disco Pigs.” She has no moral compass, really. She’s 17, for one thing. But they’re always eating sausages, they don’t give a damn. I didn’t see that as a reason not to admire her, because obviously that’s her blind spot, but what I liked about her was that she was so sure of what she was doing, such a unique person, such an individual.

That’s what it is in characters. I just want to find something individual, something about them that makes them an outsider, and that encourages me to be more that way. Because I think if I’m around other people I tend to want to fit in. I think characters in books and in movies that are complete individuals and who are not apologizing for it, they remind me to be myself. That’s why I like the character Luna Lovegood so much. I just want to have more of that energy.