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.
When you heard him talk about ventriloquist dummies, did you think, "Where the heck is he going with this?"
[Laughs] Well, as a director, you say, "OK, that's kind of frightening." But what you're also hearing in the actor's voice is passion and intensity.
You've said that when you see the Joker, you can almost imagine what he smells like.
Yeah, you feel like there's a grime to him. I showed Heath some Francis Bacon paintings, which have a particular smudged, smeared effect that I thought was very evocative of human decay and corruption.
To me, the most unsettling part of his performance is that tic where he licks his lips.
Yeah, it's almost like this lizard thing. It's very insidious, very creepy. Well, as with a lot of things that Heath would do, at first I thought it was a mistake. Because the prosthetics on his mouth would come a little unstuck. But then it became apparent that he'd really found something.