By ANGELA DAWSON

Front Row Features

HOLLYWOOD—Saoirse Ronan is growing up.

The 18-year-old Irish actress (best known for her Oscar-nominated turn in 2007’s “Atonement”) plays her first big romantic role in “The Host,” the latest adaptation of a Stephenie Meyer novel into a movie.

Ronan’s character is caught in an alien love triangle with handsome Max Irons (son of Jeremy Irons) and Jake Abel (who previously co-starred with Ronan in “The Lovely Bones”).

In this sci-fi action thriller, Ronan plays Melanie, one of the few surviving humans hiding out from aliens who have taken over the bodies of the rest of the race. After getting caught and being implanted with an alien being, Melanie forces her host body (now occupied by a being that comes to be known as Wanda) to return to her people, who are hiding out in New Mexico caves. While Melanie’s boyfriend Jared (played by Irons) adamantly rejects this alien (distinguished by her luminous blue eyes), another cave dweller, tall, blond and handsome Ian (Abel), is attracted to the extraterrestrial and becomes her protector.

Ronan admits playing two characters—one represented by voiceover within her body and the other, the more soft-spoken alien invader—was tricky. She enjoyed the challenge, though.

Dressed in a green pants, a cream-color opaque blouse and ankle-high black boots, the Emerald Isle native is celebrating St. Patrick’s Day by promoting her new movie.

Q: “The Host” is likely to draw the “Twilight” fans because it is based on a Stephenie Meyer book. Were you surprised you were offered this role?

Ronan: Yeah. I was surprised because the films she’s been involved in are so huge, and I’m not really used to those kinds of films so, yeah, I was very surprised. But when I read it—I hadn’t read the book before—I really liked the concept.

Q: Were you concerned how they were going to do the inner voice of Melanie? When did you feel comfortable it was working?

Ronan: It was a big question on my mind after I read the script how are they going to make this work, and technically, how is it going to work. At the time, it wasn’t necessarily the case that we were going to use an earpiece (that would transmit a prerecording of me doing Melanie’s dialogue into my ear) or anything like that.  But it worked very well early off.  We recorded Melanie’s voiceover before we started shooting. That was good for me to play Melanie because the voiceover was great for just understanding the character but it really helped me to understand who she was. She was sorted out. When it came around to actually shooting, I think Wanda just naturally came about. Kind of from the off, it worked. Technically, there’d be times when the earpiece wouldn’t work or the signal would go or something like that, but when it worked properly during a scene when I was essentially talking to myself, it was great. It was kind of natural for me.

Q: Was your Melanie all prerecorded?

Ronan: Yeah. We recorded it about a week before we started shooting. It was just a rough recording, but it was enough to get us through it, and enough for me to be able to react to when we were doing it on set. It worked out pretty well.

Q: You had a hand in casting of the two guys. What was it about each of them that made you say, “He’s the one?”

Ronan: Jake was great. He auditioned after we cast Max. He brought a real sensitivity to the role without it being soppy, because it could (have) easily been that. There were a few actors who were very good but they came in and almost didn’t respond to Wanda at all because they were so sensitive towards her or kind of too much, whereas Jake really had the perfect balance. His audition was passionate, because Ian needs to still have that passionate love for her but he understands that it’s impossible for him to be with her for the rest of their lives. He really seemed to have that understanding and a passion throughout the audition, and it was brilliant. I’d met him before. He was in “The Lovely Bones” (with me) and we’d had a scene together.

Q: How about Max?

Ronan: When we saw Max, whom I’d also met before, I knew how lovely he was, he’d done a brilliant audition as well and it just felt right.

Q: You had to play a teenager as well as a 1,000-year-old alien. How did you put that mix of things together?

Ronan: I don’t know. I was aware of it so I just kind of worked it in there somehow. It helped reading the book. I’ve done a few films now that have been adapted from books and I almost prefer just to read the script. But in this case, I think it was important to read the book because, I’m sure you’ve seen the book—it’s this size (she indicates with her fingers a thick book)—and there’s a lot of detail in it, which Stephenie is very very good at doing. There’s a lot of detail to back story and the characters, their history, how the resistance came about—all that kind of stuff. So I thought, in this case, it would be beneficial for me to read it, so I guess understanding all that stuff. It was good for the character of Wanda (for me to know) what other planets she’d been to, what she’d gone through, what kind of other creatures she had become for a certain amount of time. It was something I’d read and put in the back of my head and then got on with it.

Q: This is your first big romantic role, and it’s two guys.

Ronan: Yeah. Concentrated. (She laughs.)

Q: Were you and your parents ready for that? Did you jump into it with both feet?

Ronan: Well, I had to. I was fine doing it. I’ve done romantic scenes before, but never as much as “The Host.” Obviously, it’s a romantic story but you don’t want it to completely take over the whole story, so as long as it didn’t do that, it was fine. I was very comfortable with the guys, as I said. I’d met them before and we’d done rehearsals. It really does help. We’d rehearsed for a couple of weeks before we started shooting and that made a very big difference as well, I think. Being comfortable with each other and also being able to have a laugh—that makes such a big difference when you’re dealing with those kinds of scenes. Because I find when it’s too intense all the way through, I can’t take it, but if you’re able to have a laugh, it’s great.

Q: What type of film have you not done yet that you’d like to do?

Ronan: I’d love to do a musical and a silent film. I actually said that before “The Artist” came out.  I said I’d love for someone to make a silent film. I love it when there is great dialogue but I really enjoy doing scenes where nobody says anything. As an audience member, you can get so much out of that. With something like “Amour,” which came out, so much of what’s brought out on screen is unsaid. And so much of the story is unsaid. It’s just this silent dialogue between these two older people, this old married couple that have been through so much together and you didn’t need them to say too much. And I think so much of the time you don’t need that much dialogue so I’d love to do a film like that.

Q: You started acting at a young age. Are there actors or actresses that you look up to who also started out as kids?

Ronan: Someone who I’ve always loved (but) I haven’t made films like her, but I love that she’s directing stuff now, is Drew Barrymore. I think she’s brilliant. She started out when she was very young but at the same time, I’ve been doing this for about 10 years, and it’s really been a massive, the focus really in my life, almost every single day, there’s something to do with work, and it’s fantastic, and, yeah, I’ve grown up with it for the last 10 years, so I really respect someone like her who has just gone with it and she’s really grown with it and she’s such a brilliant actress and she seems like such a lovely girl as well.