Producer Frank Marshall has earned his reputation from working in the movie business for over 35 years, mostly working with Steven Spielberg on movies like Raiders of the Lost Ark and the Amblin films, but also having huge hits on his own with blockbusters like The Sixth Sense and more recently, the Jason Bourne trilogy.

While we were talking to Mr. Marshall about The Bourne Ultimatum, we wondered whether there was any serious possibility about a fourth movie, after Matt Damon has told reporters in recent months that he's reticent about returning. "There were only three books written. I know they've written a fourth but it wasn't written by Ludlum," Marshall said. "Look, we would love to continue the franchise. We just need a great story, and we're not going to do it unless we have a great story, but we are working on coming up with one, and Matt said to me, ‘Look, you hand me a great script, I'm in.' Unfortunately, we're not able to do any writing at the moment, but we're all thinking about it."

He also has a bunch of new movies coming out next year including The Spiderwick Chronicles, Wayne Kramer's Crossing Over and David Fincher's The Curious Case of Benjamin Button, but no movie is more anticipated than his latest with Spielberg, that being Indiana Jones and the Kingdom of the Crystal Skull.

He told us why Steven and Harrison Ford felt that now was the time to return to Indy. "It's kind of been out there in the air, but we never had the right script, and we kind of put it on the backburner and then back in 2000, we all went to the AFI Lifetime Achievement Award for Harrison. George and Harrison and Steven and I and Kathy were all backstage all dressed up and we were looking at clips from the movies and we thought, ‘God, those were really fun. Maybe we oughta really focus on trying to do another one." And that's what happened. David Koepp came up with a great script finally, and we're done shooting and now in the editing process. It's pretty amazing."

"What we've done is we moved it from the '40s to the ‘50s so we're acknowledging that everybody's 10 or 15 years older and it plays into the story," he told us when asked about how things would be different from the earlier movies. "We're not trying to hide that Harrison's older, but we have Shia LaBeouf coming in as his sidekick, so we've got a young element. The best way to describe the movie is that it's an Indiana Jones movie. It's got all the style and elements of the old movies, and we're not really trying to do anything different."