In an attempt to stretch his persona from pretty-boy heartthrob we've come to know from his High School Musical days, Hairspray, or 17 Again, Zac Efron, 22, reveals his "serious side" in the over-the-top weepy, Charlie St Cloud. Not unlike Leonardo DiCaprio's rise to fame post-Titanic, Efron is making an effort to shift the focus from frothy fare to smaller, edgier movies.

Speaking candidly about his strategy and his idol, whose career he would like to emulate, Efron says, "I can't help but watch other actors who have matured and gone through the same thing I did. Guys like Leo, I watch the movies they made. As great as Titanic was, he didn't stay in that one place, he evolved and tried new things. He's amazing. I realised that that's the way to stay relevant, by experimenting. I want to push myself to see how far I can go."

Based on the 2004 novel, The Death and Life of Charlie St Cloud, Efron makes the best of this melodramatic fable about the enduring bond between brothers after one of them dies in a car accident. "This was a new challenge for me, a new place to go, and something to try. It was kind of scary to get there, but that's what I wanted. I wanted to get pushed." It's for this reason he turned down the lead role in the remake of Footloose, which would have been another singing and dancing platform. "It's not that I won't sing and dance again in a movie, but not right now."

Efron reunites with 17 Again director, Burr Steers, a former actor whose adoring lens lingers on Efron in almost every shot. Steers talks about the phenomenon that surrounds Efron. "It's like the Beatles. It's unbelievable the kind of frenzy and mayhem that follows him, but he handles it all so gracefully," he says. "On the set, there were kids waiting endlessly and no matter where we were, he'd have to sign autographs for at least an hour. Even after the longest days of shooting, he'd have to go out there, and he'd do it. He'd always give them time and a smile. He appreciates it. He understands what it does for him." Unlike his peers who constantly complain about the perils of fame.

"It's really hard to put into words what it's like, but I have to put myself in their shoes and understand that feeling. I had the opportunity to speak to Michael Jackson once on the phone. As soon as I heard his voice, the emotional floodgates were opened. I was talking to my idol on the phone and I didn't know how to react. I was too emotional to even speak. I think about that, and then I see the look on some of these girls' faces and I hope I'm not disappointing them. I'm very proud to be that for them and I hope I can pull through for them, but I'm not sure," says the humbled actor.

Suggesting that the Twilight frenzy might have been somewhat of a relief for him, he laughs, "In terms of the paparazzi, I got to take a step back, and I have to admit, that was great. It gave me a minute to regroup." He pauses. "But I'm not going to complain about that kind of thing. I can go where I want. Actually, the best place to go if you don't want to get recognised is Japan, because you can wear the sickness mask."

The movie also stars newcomer, Canadian actress Amanda Crew as his love interest. His mother is played by Kim Basinger in an all-too-brief appearance and Ray Liotta has a small but pivotal role. Of course, the film requires a giant leap of faith from the audience, given the material is about a relationship he has with his brother, a ghost whom he plays baseball with each day, as well as other paranormal subplots.

Says Efron, "When it comes to stuff like that, I'm like the next guy as far as whether I believe in ghostly activities or not. I'm not crazy into it but I definitely think I've felt some sort of presence before. I think I may have lived next to a haunted house when I was growing up."

While many were of the view that Efron may be a flash-in-the-pan, all signs point to a long career, the way it was with DiCaprio. Says Steers, "It's interesting. Almost all leading men were kid actors: DiCaprio was a kid actor on Growing Pains, and Ryan Gosling was a Mouseketeer, and of course, Johnny Depp was in 21 Jump Street. They all had something different about them, something charismatic in some way that set them apart," he says. "As for Efron, Steers gushes, "If I have the opportunity to work with him again, a leading man who is the most enthusiastic, hardest working person on the set? Sign me up," he laughs. "I'll do that in a second."

Who: Zac Efron
What: Movie Charlie St Cloud
When: Opens at cinemas today