BEVERLY HILLS, California — Until now, it's simply been known as "The Untitled Zac Efron Project," a mysterious movie that is to serve as the "High School Musical" star's first solo vehicle. But now, with Efron's "Hairspray" just a few weeks away, the fast-rising actor gave us the scoop on the top-secret project — along with his thoughts on going back to "High School" for a third time.

" 'Seventeen' is a cool project that I am looking at right now," Efron said of the formerly untitled flick, revealing the title as well as the fact that it's currently in the final stages of pre-production. "It's kind of like a reverse 'Big,' about a guy who is older and his life never came out how he planned."

Invoking comparisons to the 1988 comedy classic that not only made Tom Hanks a superstar but also earned him an Oscar nomination, Efron said the concept of "Seventeen" is to change up the formula.

(Watch Efron talk about the "Seventeen" role that takes him back to school right here.)

"[The character] wishes he could go back to high school, and sure enough, he wakes up and he is young again, he is 17 again," the actor/singer said.

"New Line really wants to make this thing," echoed "Hairspray" director Adam Shankman, who is poised to reunite with his leading man by serving as a producer on "Seventeen." "Hopefully, this will be Zac's next project, and hopefully it will be going in the fall."

In "Hairspray," Efron takes his musical-leading-man act to the next level, playing Elvis-like teen heartthrob Link Larkin (see " 'High School Musical' Stars Have Sequel, Solo Projects In The Works"). According to Shankman, "Seventeen" will continue to evolve Efron's career by mixing in drama much like "Big" before it. "It is a comedy, a teen comedy, with a little more teeth than he has been seen doing before in the past," he said. "We want to show [Efron] in a more aggressive, but funny, light."

"It's just about 'What if you went back to high school, and you knew what you did now?' " the 19-year-old said of the script, written by "Bringing Down the House" scribe Jason Filardi. "It's cool."

With a grin, Efron said that there will be an older actor playing the grownup version of his character, and that he'll be playing the post-transformation teen. "I hope I don't play the old guy," he laughed.

Finally, Efron briefly addressed rumors that he and several of his fast-rising co-stars might not return for "Haunted High School Musical," the third film in the super-successful series. "At this point, it is not in my hands," he said of the behind-the-scenes negotiations. "I mean, I would love to do a third 'High School Musical'; it would be a great way to finish off the series.

"To start with a TV movie and finish off on the silver screen would be a great legacy for the 'High School Musical' series to leave," he said of the flick, which will be released in theaters (see " 'High School Musical' Stars Dish On Sequel's Showstoppers, Love Triangles").

Efron joked, however, that he might be too chicken to take on the "Ghostbusters"-esque proposed premise. "You know, if [East High] is haunted, I might have to reconsider," he grinned. "Because I don't like ghosts."

Check out everything we've got on Zac Efron.

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