Director Tony Gilroy and George Clooney on the set of Michael Clayton. Myles Aronowitz/Courtesy of Warner Bros.

Apparently you also shot in the house where you grew up. How crazy was it to have George Clooney acting in your childhood home?
Oh, my god. Bizarre. Totally bizarre.

Was that pre-planned?
No, not at all. No, no, I never had any intention of doing that. We were looking for the field in the film. And because we had no money, they wanted to find a field within a certain driving distance from New York City, because we could only shoot in that field for five minutes in the morning and five minutes in the afternoon. It takes place at dawn. Literally. Five minutes of shooting each time — if the weather was right. So we needed some place that was close to the city. Every day they put more gas in their location cars and they'd bring back pictures. But nothing was good. My brother, who cut the film, was up at my parents' house, and he said: "Tony, go by the trestle and take a picture of the field and see if it hasn't been built up yet." It's about 65 miles north — too far to commute but everybody loved it so much. It was so perfect. So they said: "All right. Let's make a mini-location out of it. We'll move the company upstate there for one week." But then we needed cover sets in the middle of the day. And now we're back in my neighborhood, where I set this thing in the first place, and all of a sudden we're shooting in my old neighborhood. And I'm sleeping in the bed I grew up in. George Clooney, eating lunch at the volunteer firehouse. And then, on top of that, it was during the Academy Awards and Jon Stewart was hosting the Academy Awards and they needed those little sequences, the little comedy sketch in the beginning. I'm breaking for lunch and [I hear]: "Do you want to go next door and meet Jon Stewart?" I go: "What are you talking about?" "He's in the house next door. They're filming something for the Academy Awards. He and George in bed together."

That was shot there?
Yes. I said: "I can't even deal with this. This is too much!" The only people who really realized how surreal that was were my brothers. It was beyond bizarre.

Tilda Swinton in Michael Clayton. Myles Aronowitz/Courtesy of Warner Bros.

Tilda Swinton's character is intriguing, too — in some ways, a villainess at the end of her rope in the same way that George's character is.
She's at the beginning of a path that he's sort of been on. But she's not equipped. I told Tilda before we started: "Imagine that you're a concert pianist. And you're a very accomplished concert pianist and all of a sudden you're asked to go play with [jazz musician] Ornette Coleman. It's music. It's all music, right? But it's the wrong music. She's not in a milieu or a pace or anything that she's equipped to deal with."

Most of your films that you have written have issues of moral complexity where the lead characters are confronted with gray areas and must make difficult choices. It's a touchstone in almost all of them. What attracts you to this theme?
I don't know. I think it's basic drama, isn't it? When you finally get down to the choices that people make and how they're going to live. I wasn't aware of how thick a cord it was through my work until it came time to start talking about the film a month or so ago. You begin to figure out how you're going to talk about the movie and put it in context with whatever else you've done. And there is a common thread. I don't know the answer to that. It's what interests me, I guess. I'm interested in the villain inside. And it makes for good drama. It makes for good characters.