by Jen Chaney

You probably know Justin Theroux best as an actor.

During his 15 years in the movie business, he’s popped up in films as varied as ZoolanderMulholland Drive and Miami Vice, and on an equally wide range of TV series (Six Feet UnderThe District and Parks and Recreation among them). You may not realize that Theroux is also a screenwriter, who co-penned Tropic Thunder and wrote a little film due to debut in theaters this weekend: Iron Man 2.

I recently got Theroux on the phone for a quick chat, during which we discussed his time growing up in Washington, D.C., his childhood fixation on Iron Man and an important question that Iron Man 2 director Jon Favreau also will address in a Q&A slated to appear in Celebritology tomorrow: What person, dead or alive, would you like to see Iron Man fight? Read on to fin out Theroux’s answer.

Thanks for taking the time to talk to me.

It’s the Washington Post, dude.

It’s your hometown paper, right?

It’s my hometown paper! I used to deliver the Washington Post.

Did you really?

Absolutely. For six years or something.

Wow. So you grew up in Northwest D.C. and you went to the Field School, right?

I went to a bunch of places. Field School was one, and then I ended up going to a boarding school in ninth grade. But I went to Lafayette Elementary, I went to Field, I went to Annunciation. I got kicked out of all kinds of places.

I want to talk to you about how you got the job to write Iron Man 2. From what I’ve read, Robert Downey, Jr. pretty much got you the gig. Is that a mischaracterization?

Well, no one gets anyone the gig, but he definitely kicked the door open for me. I worked with him on Tropic Thunder and we hit it off in such a way that he was like, “I really would love it if you could meet the guys at Marvel, and Jon [Favreau],” so I went over there and had a big long meeting with them, and we sort of sniffed each other out. And it seemed like it would be a great fit. And it was.

Were you a big Iron Man fan?

I strangely was. I mean, I wasn’t one of those kids that had a lot of toys or anything like that, but I did have an Iron Man doll when I was a kid. And I sort of kept loose touch with him as I grew older. [Laughs] But yeah, I’ve always loved Iron Man.

What spoke to you about those comics as a kid?

I think I liked that he didn’t have a superpower, necessarily, you know what I mean? He was a human guy who had something lodged in his chest, but he couldn’t see through walls. He was just one of those guys who was sort of tech-based. He’s sort of like the ultimate dumptruck, you know what I mean? I liked trucks when I was a kid, too.

He was this — just a Swiss Army knife of a guy who was obviously rich and powerful, and got a lot of chicks and stuff like that. So that’s all sort of cool. But he was strangely identifiable in that he had all kinds of flaws and imperfections. He wasn’t one of those guys who sort of ripped off his shirt and became someone else, he had to put something on. And I think there’s just something in that metaphor of someone who puts on armor to take care of stuff. That was just sort of cool.

When you got the job, that must have been a surreal dream come true.

It was super exciting, yeah. I was fortunate in that Robert has such a clear voice for that character that it was sort of easy to slip into what he was already doing, you know? It was a super dream come true to write for this guy, and also, in particular, to write for the way Robert was doing him.

I also have to think it was a little daunting because this is, what, your second screenplay?

Yeah, it is.

So is it Robert Downey, Jr. and Jon Favreau who have the story credit, but you wrote the screenplay?

I actually don’t know the answer to that question. But we basically all built the story together. We all sat in a room with a blank slate and said, “Okay, what’s the movie out of this? How does this work, you know? What would the fans want to see next?” We really started with nothing. We all sort of unpacked our trunk of things that they’d like to see, or wanted to see, and we all sort of broke the story together.

So it was a collaborative process. It wasn’t like you felt you were taking this on alone.

No, that was what made it so beautiful, actually. I definitely went away and did the pages alone. It was such a great support team with Robert, who knows the voice so well; Jon, who knows the character and story so well; and Marvel, who, you know, also knows exactly what they’re doing and what’s valuable about all their heroes in this world. They were really helpful just as far as understanding what they call the shareholders — the fans — and what they want out of these movies. It was a great table to be at, you know, when you’re trying to create the second film.

Are you thinking in the back of your mind as you’re writing, “How are the fans going to respond to that?” Because we’re in a culture now where there is so much response on the Web to every drib and drab.

And we paid attention to it. Not 100 percent, you know, because there’s times when fans can ask for crazy things that are just not feasible. But you do try and do some sort of finger-in-the-air polling. Moreso, what did people like so much about the first one, and how can we tweak that and give it to them in a way that’s highly entertaining?

One of the things that’s great about Marvel in general is that they don’t test their films. Most films go through an extensive testing process, which oftentimes can press all the nutrients out of them and [remove] what makes them interesting. Marvel’s really good about doing internal — even though they’re studio heads and all the rest of it, they’re actually probably the biggest fans of their heroes. So there were times when we’d be banging our heads against something, and Kevin Feige [Marvel’s President of Production] would go, “No. I know the fans at this moment and what they want to see is this.”

It didn’t go through that sausage-making-factory process of people ticking boxes and going, “I like this, hated that,” and then the subsequent editing.

So, I don’t know if you’ve seen some of the viral videos that have been circulating on the Web, particularly the one of Iron Man punching Hugh Grant?

No, I haven’t.

You’ll have to log on and check it out. But that prompted a question that I also plan to ask Jon Favreau: Who would you like to see Iron Man fight, dead or alive?

Oh my God! Osama bin Laden. [Laughs] Who would I like to see him fight? I’ll combine that with “who would you like to have dinner with?” Oscar Wilde.

Oscar Wilde. I like that.

The common question is, who would you like to have dinner with, so now it’s who would you like to see Iron Man punch… Oh gosh, I don’t even know. An ex-girlfriend? [Laughs]

David Sullivan from 32nd Street. He used to beat me up when I was a kid.

All right. I think you’ve officially gotten your revenge.