Damon Lindelof has revealed he is "excited" that George Clooney has signed on for Tomorrowland.
The Ides Of March star has agreed to take a lead role in Disney sci-fi film, which also stars Hugh Laurie and Britt Robertson and will be directed by Mission: Impossible - Ghost Protocol filmmaker Brad Bird.
Damon said at Disney's D23 Expo: "He liked the script enough to take the leap with us, so we're pretty excited about that."
The storyline for the film is being shrouded in secrecy but is based on a mysterious box marked 1952 that was supposedly found by a construction crew in a locked room in the Disney archives containing a lot of material.
The Star Trek screenwriter admitted they showed the box to the Hollywood star.
"We brought this box over to his house. We made him put on the gloves that Disney makes you put on if you're going to handle the artefacts and then we told him the story. He said, 'I'm interested. Send me the script when it's done,' which we did," he recalled.
Some of the items in the box have proved to be faked, relating to Walt Disney and the imagineers who started working on the Tomorrowland part of Disneyland in 1952.
"Some of them are real - we just don't know who put them there or why. Our job as storytellers is to ask, what if everything in this box was put in here for a reason?" said Damon.
Damon has shot down rumours that the film is about aliens, telling Empire: "When we first started talking about it, the movie we were referencing was Close Encounters, so people incorrectly deduced that it was about some sort of alien contact, which we've ruled out."
Tomorrowland is scheduled for a December 2014 release.