This was Rose Byrne’s introduction to American audiences. Not only did she get to make out with a nude Brad Pitt in an ancient greek fantasy land, but she got to do it after he spent months in the gym preparing for his role as Achilles in the swords-and-sandals epic Troy. I know–yowzas, right? You’d think one’s career would tumble downhill from there, but not so for the Australian beauty. Since then, she starred as French aristocrat opposite Kirsten Dunst in Marie Antoinette, an astronaut trying to reignite the sun in Sunshine, and an army medical officer in the zombie horror film 28 Weeks Later. And while cultivating her film career, Byrne has been putting in a Golden Globe-nominated performance alongside Glenn Close in the hit FX legal drama Damages.

Her latest project is Knowing, a supernatural thriller costarring Nicholas Cage. The film was directed by fellow Australian Alex Proyas (The Crow, Dark City) and is at times terrifying, at times baffling, while asking some profound questions about determinism, fate, and the apocalypse. So when I met Byrne at the Ritz-Carlton last week, our conversation helplessly veered towards religion, the cosmos, and the end of the world, even though all I really wanted to know was what Brad Pitt’s biceps actually felt like.

What excites you most about the film? I think Alex Proyas is a real visionary. So if you’re a fan of his work, then it’s a real exciting thing to add to his body of work. I think it’s really, really smart. And he creates a tone in the movie which I think is just so foreboding and eerie, and then progresses to be quite surprising and revelatory.

Did watching the disaster set-pieces scare you as much as they scared me? Oh yeah. Did you get on the subway since then? The action is so real. Often action is a confusing device and it doesn’t make sense, or it’s just absurd. But it’s not like that at all.

You had to audition for this film. Is that strange, considering you’re a Golden-Globe-nominated actress, and the filmmakers already know who you are? Well I’d known Alex before, so I was happy to come in because I’d always wanted to work with him. In a way you get to see if you fit the role and what you can do with it. It’s never a pleasant experience, auditioning. It’s a bit traumatic. I’d never wish it on anyone. But I’ve been doing it forever so I’m used to it.

Did you audition opposite Nicholas? No, I actually auditioned with the little girl who plays my daughter.

You’ve said rejection breaks your heart every time you don’t get a role. Is that still the case? Oh, sure! Absolutely. I mean, if you’re desperately dying to do it, then of course. But there are other parts that you go “Oh, I wasn’t meant to get that.”

In the film the Earth is threatened by a scientific force I was never aware of before. Do you know if that’s even possible? I’m not particularly scientific so I don’t have an incredible knowledge in terms of those things. What do you think?

I’ve never heard of it before. And if it’s possible, I think it’s very scary that it could happen at any moment. What about the Mayan theory that it’s all over in 2012?

Um no, but the trailer for the movie is quite cool. Wait, there’s a movie?

Yeah, it’s called 2012 and the teaser is really creepy. Wow really?! Oh my God, so it’s about the Mayans?

Yeah, in the trailer, it looks like a huge tidal wave does us in. Well the calendar just stops. It starts before Christ, and then it just stops. There’s no indication as to why it stops or how. It just ends there. Thom Yorke thinks it’s going to be the end of the world. That’s why he named his kid Noah.

Nicholas Cage’s character wrestles with the reason we’re on Earth—whether it’s all just a cosmic coincidence, or whether there’s a greater purpose. Do you ever think about those things? I did a film called Sunshine with Danny Boyle and we actually spent a lot of time talking to scientists about all of these sorts of things. And it got me thinking that just the fact that we are here is a miracle.

That’s two “sun” movies you’ve done. Yeah, I was thinking about that. Maybe it’s because I’m a Leo and I have this relationship with the sun. But yeah, we had a whole education on the sun. And how the amount of gravity we have here is the perfect amount with part oxygen so everyone can breathe.

But do you think life is a result of random chemical reaction? Strange, because the fact that we are here is such a miracle. So is it purely chance? And that’s it, that’s the miracle? I do believe it’s a series of chemical accidents. That’s the type of way I choose to believe. Maybe because I’m not religious. Were brought up on religion?

No, I wasn’t. I wouldn’t call myself an atheist, but more agnostic. Yeah, I’d say I am agnostic. My parents are atheists. Well, my mum is. I’d say my dad was agnostic. But I think that I’m probably agnostic, yeah. I think the fact that there are so many different religions in the world immediately makes me suspicious. How can you know which one is right? Do you know what I mean? Is the Jewish religion right? Or is the Christian religion right? Or is the Hindu religion right?

And it’s those kinds of questions that leads to violence on a massive scale. Yeah, that’s a huge discussion. I actually have a friend who thinks it’s not religion’s fault, but that it’s our fault as a race for not using religion as a tool to guide us through life.

There are a lot of things left unexplained in Knowing. Was that on purpose? Definitely, to create conversation and foster these sorts of discussions about spirituality, and about your beliefs and the future of things, environmental things. I think it’s definitely tapered in that direction.

The ending of this film will leave a lot of people scratching their heads. What did you think about it? Well it’s strange because obviously it’s such a turn. But I think it’s definitely a testament to Al that he set, for me, the tone early that there was something rotten here. So it wasn’t so radical at the end. You knew the whole time there was something stranger going on.

What do you think is the scariest movie that you’ve done between Knowing, Sunshine, and 28 Weeks Later? Sunshine I don’t think was too scary, but the third act was pretty eerie. 28 Weeks is pretty scary, but it’s more of a jump shock. And Knowing is an eerie, foreboding film. You slowly start to get really scared. It depends on what scares you too. Because Knowing is more of a psychological thriller, and Weeks is more traditional horror shock.