Bat Trick

Your first Batman movie, "Batman Begins," was epic and globe-trotting. But "The Dark Knight" is almost entirely set in Gotham.
In making a sequel, one of the demands I felt was to make it bigger, to expand the canvas. But it was clear to me that, having gone around the world in the first movie, that wasn't the way to do it this time. I was thinking a lot about films like Michael Mann's "Heat," where you have a story that is contained within a single city, but that city feels like a truly massive place.

Why is Chicago, not New York, your Gotham?
Well, I grew up partly in Chicago. And when Nathan Crowley, my production designer, first set up here in my garage, putting together composites of what Gotham might be, we started imagining a city with all these layers, with bridges and subterranean streets and tall skyscrapers. And at a certain point I said to him, "I know where this is. This is Chicago."

Everyone from the first movie is back except Katie Holmes. Maggie Gyllenhaal has taken over her role as Bruce's love interest. Isn't it disruptive to have a new actor playing an old character, with no explanation?
Well, it's not ideal. But this character is an integral part of the story. So when Katie didn't want to do it, I had no choice.

Prior to the opening of "Batman Begins," there were many published reports about dismay at Warner Brothers over the way Katie's personal life—specifically her romance with Tom Cruise—became an unwelcome distraction. Did that have anything to do with her not returning?
No, I asked Katie if she wanted to do the part, and she passed. You'd have to ask her for the exact specifics of it, but I would have been perfectly happy to have her back. And indeed, I offered her the part. But she couldn't do it, and Maggie stepped in, and she was great.

I know you are loath to talk about Heath, for understandable reasons, but there's no avoiding the fact that when you watch the movie, his performance is so exciting that it's the first thing you want to talk about.
Yeah, I know. I've been waiting all this time for everyone to see it, and working very hard not to screw it up.

What about Heath made you cast him?
I'd met Heath a couple times over the years about different projects, but nothing ever worked out. One time he gave me a speech that a lot of young actors have given me, where they basically say that they haven't achieved, as serious actors, what they want to before they're pushed into being movie stars. And of all the actors who've given me that speech, he's the only one that I would actually want to pay $10 to see give that kind of performance. And he did it in "Brokeback Mountain." The stunning lack of vanity, the sheer loneliness of that character—it's a staggering performance. So when I heard he was interested in the Joker, there was never any doubt. You could just see it in his eyes. People were a little baffled by the choice, it's true, but I've never had such a simple decision as a director.

You and Heath evidently had lots of conversations about shaping the character.
He'd call me from time to time, just to talk about what he was doing. And frankly, it was pretty hard to relate to on the other end of the phone—when he'd talk about looking at ventriloquist dummies and the way their mouths moved, the way the voice would sound as if it's disembodied.