Filming "The Dark Knight"

Christopher Nolan directs "The Dark Knight."
Christopher Nolan directs "The Dark Knight." Batman, Christian Bale

When Gotham City needs emergency help, the "Bat Signal" summons Gotham's own knight. And when the keepers of the Batman flame needed a director for this summer's latest incarnation of the legend, "The Dark Knight," they called once again on Christopher Nolan, whose dark vision was realized in large part because of a spine-tingling performance by the late Heath Ledger as the Joker. Bill Whitaker takes us to Gotham City:

Even in this summer full of cinematic superheroes, it's a sure bet when "The Dark Knight" swoops into theaters this week, legions of Batman fans will follow in his wake, into a world both comic and complex.

Batman, a.k.a. Bruce Wayne, is full of questions and doubts, challenged like never before by a villain like no other.

"In continuing the story and addressing where this story goes now that Batman is established, there is an inevitable darkness to where that story goes," writer/director Christopher Nolan said.

Nolan, who brought "Batman Begins" to the screen in 2005, returns to direct this sequel, "The Dark Knight."

"This film deals with the response from criminals, personified in the idea of who the Joker is," he told Whitaker - a conflicted hero versus a villain, pure evil.

As played by Heath Ledger in his last completed role before his death in January, the Joker is not some merry prankster in pancake makeup, but a demon, a terrorist, hell bent on anarchy.

"We're saying, 'What's the most frightening thing in the world today?' And to me it's anarchy and chaos, the things the Joker represents," Nolan said.

All this nightmare-inducing chaos from a 37-year-old director with the polished air of an English professor, who sees deep meaning in Batman.

(Warner Bros.)
"There are echoes of, you know, 'The Count of Monte Cristo' and 'The Prisoner of Zenda.' This sort of tortured, grand, operatic figure, this man who disguises himself in the cape, but is actually one of the most prominent citizens of society," Nolan said. "But no one knows that it's really him.'

"You take this character very seriously," Whitaker said.

"I've always felt with movies, sort of big, blockbuster movies, that the more they relate to real life, the more there's a tactile sense of the real world, the more exciting they are," Nolan said.

Nolan cast Christian Bale as his troubled hero in "Batman Begins" and "The Dark Knight" because of Bale's intensity.

"It's a summer blockbuster," Whitaker said to Bale, "you're wearing a cape and the costume and the whole bit, but it's not a 'comic' movie."

"No, it's not," he agreed. "It looks much more gritty than that, much more real."

Add Heath Ledger's menacing, mesmerizing Joker, and Nolan is offering up that rarest of summer fare - a blockbuster with brains.

"We certainly wanted to make as intelligent a film as we could," Nolan said. "And that's where the strength of the performances comes in."

(Warner Bros.)
Heath Ledger's performance as the Joker ("This town needs a better class of criminal and I'm gonna give it to 'em") already is generating Oscar buzz.

"He makes the character hateful and odious, and yet somehow there is some level of charm though," Nolan said. "When he comes on the screen, you're excited to see him again.

"That's the genius of great actors, and as a director, it's incredibly exciting to watch a great actor craft a performance like that."

The big-budget "Dark Knight," reportedly $180 million, is a long way from Nolan's beginnings as a director.

He made his first feature, called "Following," right out of college for $6,000. That movie and his next, "Memento," revealed a confident, creative storyteller.

"Memento," about a man with no short-term memory searching for a killer, unfolds forward and backwards in time. It won him a cult following, an Academy Award nomination, and entree to Hollywood.

After one fairly solid hit, "Insomnia," Nolan convinced Warner Brothers to hand him the reins of their fabled, though faded franchise: Batman.

"I first encountered Batman through the TV show," Nolan said.

That campy 1960s version of the Caped Crusader was just one of Batman's many incarnations. On the big screen there was director Tim Burton's darkly, stylized "Batman" almost 20 years ago, with Micheal Keaton as Batman and Jack Nicholson as the Joker.

Then the superhero did super box office through three sequels, before the franchise ran out of steam.

Paul Levitz is president of DC Comics, which has published Batman since the character's inception in 1939 and has been guardian of his image in everything from movie serials to animation and action figures. "Batman was, from the very beginning, one of the two or three most popular superheroes in comics," he said.

Levitz said Warner Brothers rolled the dice tapping Nolan to reboot the movie franchise, and won.

"It's one of the happiest circumstances in my career that they had the inspired idea of reaching out to Chris Nolan," he said.

Emma Thomas, Nolan's wife and producer ("I can't ever imagine producing a film for anybody else, actually"), was his college sweetheart, and has been by his side through small films and blockbusters.

"I think that our approach to each film has kind of been the same, whatever the budget," she said. "You know, you want to tell a story that people want to see."

Yet the couple find themselves in the sensitive, even uncomfortable position of having to promote the film and Heath Ledger's performance without exploiting the death of a friend.

"To be honest, it's hard to relate the two things in a way," Nolan said. "I know that sounds strange. Somebody dying, somebody you've worked with and been friends with, is an extraordinary tragedy and doesn't really relate to the film in a strange way."

"Did you feel, sort of an added responsibility to honor his performance?" Whitaker asked.

"Yeah, I felt a huge amount of responsibility on this film," he said. "And you know, Heath's passing makes just all the more true. It also just makes it more important to me that, you know, his performance gets seen by as many people as possible. They really get to see what he did, because I think it's a pretty glorious performance."

Early reviews have been positive, Internet ticket sales sizzling. All Hollywood is betting "The Dark Knight" will soar high once again.