"The Dark Knight" opens July 18 in the U.S.

SPOILER WARNING: The following contains some spoilers for "The Dark Knight."David Goyer wrote 2006's "Batman Begins" in collaboration with writer-director Christopher Nolan. For this year's sequel, "The Dark Knight," Nolan brought in his brother Jonathan (author of "Memento" and screenwriter of "The Prestige") to assist them in crafting the dark Batman tale. CBR News met with David Goyer and Jonathan Nolan to discuss their new film, which opens July 18 in the U.S.Bringing the essence of the well-known villains the Joker and Two-Face to Christopher Nolan's vision of Gotham was of paramount importance to David Goyer and Jonathan Nolan. Though "The Dark Knight" does not follow a specific comic book story -- Alan Moore and Brian Bolland's "The Killing Joke" for example -- the writers feel the spirit of that famous story permeates the film. "I think there's a ton of it if you look at it from a different perspective," said Jonathan Nolan. "What is the Joker trying to do in 'The Killing Joke?' He's trying to drive one of Batman's allies crazy." Goyer added, "A little bit of that dynamic between the Joker and Batman ... we definitely pulled from 'The Killing Joke.'"In preparing to write the film, Nolan and Goyer read much wider than the 1988 Batman novella. Indeed, Nolan thinks it would be easier to find a story they did not look at and research. "We probably read all of them. I grew up a Batman fan. David did, too," he said. "So there's already a lot of that [knowledge] in there. And when you embark on these things, DC sends you everything."

Scene from "The Dark Knight"

"Obviously there's some of 'The Long Halloween' in there," said Goyer. "There's some [Frank] Miller stuff. I think in this one [there is] less [of] some of the Denny O'Neil stuff." In that research effort, Nolan said they arrived at the core of the Joker before reading his initial story. "Midway through the process, [we] went back and looked at the first appearance of the Joker in the books," Nolan recalled. "There are a couple of moments in 'Batman' #1 which are almost shot-for-shot moments that emerged in 'The Dark Knight.' [It] felt very gratifying to reverse engineer your way back to what felt like a starting point for the character."The actual writing of the film required Christopher Nolan to first make the choice to come back to Gotham. "It was not a forgone conclusion that we were going to do a second film even when we started talking," said Goyer. "There was a long process where we talked about whether or not this story we were coming up with was worthy or better than the first one." When director Nolan made the decision to go ahead, he and Goyer proceeded to hash out a plot. Writer Nolan recalled, "David and Chris went off and butted heads for awhile and came up with this story, a really great story." When Goyer left to direct a film, Jonathan Nolan came on to write the full screenplay. "They handed it over to me and let me take a crack at the first draft. Chris is always going to take the last pass on his scripts going in. He's a writer as well as a director, kind of 50/50, so our job is done well in advance of the film. For us, it's kind of been this fascinating experience of getting our work done and waiting a couple of years to see what comes out the other end." Nolan characterized that end product as, "Enormously satisfying."

Scenes from "The Dark Knight"

In bringing the Joker to the vision of Gotham outlined in "Batman Begins," the writers found they could bring a vital aspect of the character unseen in previous iterations. "The thing I am most excited about in regards to that character is, at least for me, it's the first time on screen that he's really frightening," Goyer said. "That's what I've been telling people. You're really going to be frightened by him." For Nolan, the appeal was that the Joker "cuts through the film. That he's an elemental." To that end, Goyer and Nolan chose to give the Joker no origin. "He just is. He's more interesting without [it,]" Goyer explained. Nolan agreed the ambiguity was essential. "Chris and I have had this argument on a couple of different films, but I'm always really interested in the idea with these characters that there's an ambiguity there that's functional; it's purposeful," he said. "The idea with the Joker: [if] he had a back-story and if one of the stories he told you was true, somehow, it would reduce the character. It's more frightening because, in a sense, there is no mystery there. There is no back-story. He is exactly what he presents himself to be; which is an anarchist." Asked if it was difficult to write such a character, Nolan responded, "Weirdly, somewhat frighteningly, he was the easiest character I've ever written. I think that character is common to a long history [of literature]. You'll find a version of him in almost every culture going back thousands of years. It taps into something elemental. The jokester. The trickster. It just kind of appears."

Scenes from "The Dark Knight"

Goyer finds the character of the Joker freeing for a writer. "He doesn't have a cause, so you don't have to justify any of his actions," he said. "So he's one of these rare instances in telling a story where the whole point of the character is that **you're not** justifying what he's doing. And his one stated cause, initially, in the story is: Batman has to turn himself in. That's what he wants. But then, later on he says to Batman, 'I would never kill you.' He completely abandons that idea." Though not initially part of the story, Harvey Dent soon became the soul of "The Dark Knight." "It became apparent as we were talking fairly early on that Harvey was actually the protagonist of the movie," said Goyer. "The Joker doesn't change and Batman doesn't really change. But Harvey is the one that changes as a result of his interaction between the Joker and Batman. Obviously, he changes in a tragic way and that means the movie has to be a tragedy." Nolan agreed, "The arc of the film is the tragedy of Harvey Dent, which is, in a sense, the origin of the villain Two-Face. Which, I think, we've told [as] a more complete story."As before with "Batman Begins," Goyer and the Brothers Nolan have not discussed a third film. "It wasn't until three of four months after 'Batman Begins' opened that Chris and I sat down and talked about another one," Goyer recalled. Ruminating on what characters they could possibly use in a third film, Goyer suggests he will buck the conventional wisdom. "In the first film we used Ra's al Ghul and the Scarecrow, who had not been in the movies before and had not been in the '60s TV show. There are dozens, if not hundreds of other characters that [are possibilities.] Everyone says you have to use the Penguin or Catwoman. Well, I completely disagree." Goyer also recognizes the danger of even mounting a third film, where so many movie franchise stumble. "It's definitely a much scarier proposition," he said. "It was a scary proposition to do 'Dark Knight' [following the first film]. It's sort of a geometrically proportionately scary proposition to try to do another one [following 'Dark Knight'], but we'll see."Now discuss this story in CBR's TV/Film forum.