The death of Ledger and the word of his incendiary performance in this film have made him the natural focus of early media coverage of "The Dark Knight." But Nolan told The Times this year that the foundation of the film is the tale and transformation of Eckhart's character, Harvey Dent, from a crusading Gotham City prosecutor to Harvey Two-Face, a maniac whose face is ravaged on one side by a horrible injury.
On the campy 1960s "Batman" television series, the writers imported pretty much every major villain from the namesake comic book -- the Joker, the Riddler, the Penguin and Catwoman, etc. -- but not Two-Face. He was simply too gross. In the comic books, the wounds come from a splash of acid thrown at the attorney by a gangster on the witness stand, but there are hints that in this film it might be the Joker who is responsible for the scars.
Eckhart won't discuss that, but he did say that the wounds are structurally deeper than in the comics: "There are fans on the Internet who have done artist's versions of what they think it will look like, and I can tell you this: They're thinking small; Chris is going way farther than people think."
There were plenty of name actors lined up hoping to get the role of Two-Face, but in the end Nolan went with Eckhart because of his "complexity and this aura he has of a good man pushed too far," Nolan said. Two-Face in the film is more of a vigilante hunting down the Joker than he is a criminal, as he has most often been portrayed in the comics. His trademark is flipping a two-headed coin, one side defaced, the other pristine, and letting its landing determine his actions, often in situations where he has a gun to someone's head.
"The difference between Batman and Two-Face is how far they are willing to go and how they make their point," Eckhart said. "Otherwise, we're talking about vigilante crime-fighting. That's what Batman is all about. He has a strong sense of justice. And Harvey Dent has an extremely strong sense of justice. His fiancée is killed. He's horribly injured. But he is still true to himself. He's a crime fighter, he's not killing good people. He's not a bad guy, not purely."
The 40-year-old, square-jawed Eckhart has a history of playing authority figures pulled away from the bright path. He was a cop on a path to destruction in "The Black Dahlia," the slick tobacco lobbyist in "Thank You for Smoking," the junior executive looking to punish women in Neil LaBute's "In the Company of Men," all of them roles in which bad deeds are simple to see but bad men are hard to recognize.
"You look at a good guy too long and it's not that exciting, it's the Boy Scout always doing the right thing," Eckhart said. "I'm interested in good guys gone wrong. They're not the bad guy, they're the good guy doing bad things."
He joins a franchise with a deep roster of serious actors onboard: "The Dark Knight" has career-surging Christian Bale back in the cape and Gary Oldman as Gotham's only honest cop, Jim Gordon, as well as Oscar winners Michael Caine and Morgan Freeman. Maggie Gyllenhaal steps in for Katie Holmes as prosecutor Rachel Dawes, the romantic interest of Bruce Wayne.
"My guy identifies with everybody in the movie," Eckhart said. "Really, all of it is more than an adventure tale, it's somewhat of a mirror of our times. It deals with some fundamental questions of what's going on in society. To me, this film is about how Batman feels about justice, how he takes care of the city, how he feels about the Joker when he meets him and sees what he is capable of doing. How he feels when Harvey Two-Face takes matters into his own hands. It's not simple, and it gets ugly. I think people will be surprised."