UNIVERSAL CITY, California — Tonight marks a bittersweet end and a promising beginning for actress Emma Watson. She and "Harry Potter" co-stars Daniel Radcliffe and Rupert Grint will battle for the final time on behalf of Hogwarts at the 2012 MTV Movie Awards, but before the big show even began, Emma turned a new page by debuting the first trailer for her next project, "The Perks of Being a Wallflower."

Watson was joined by "Perks" co-stars Logan Lerman and Ezra Miller at the Movie Awards pre-show to introduce the first look at their coming-of-age film, out September 14. Based on the novel by Stephen Chbosky (published by MTV Books), "The Perks of Being a Wallflower" follows high school freshman Charlie (Lerman) as he learns to navigate adolescence with the help of new friends Sam (Watson) and Patrick (Miller).

Let's take a look at the five key scenes from the "Perks of Being a Wallflower" trailer:

Dear Friend The clip opens with a shot of Charlie sitting at his desk on the eve of his first day of high school, penning a letter to an unnamed friend. The moment and Charlie's narration mirror the novel's epistolary format, all the while laying bare his extreme introversion and lack of real friends.

Party Time Charlie isn't on his own for too long, though, as he meets gregarious step-siblings Sam and Patrick, who invite him to his first-ever party. Charlie is not only introduced to a whole new group of friends, but he unwittingly experiments with drugs, thanks to a delicious batch of pot brownies. It's in this moment that Charlie feels noticed for the first time as Patrick toasts him: "You see things and you understand. You're a wallflower."

"The Rocky Horror Picture Show" In a blink-and-you'll-miss-it bite, Watson can be seen looking uncharacteristically provocative in a feather boa and slinky black lingerie. It's a small taste of the posse's production of "The Rocky Horror Picture Show," which they faithfully stage weekly. The musical becomes a bonding opportunity for Charlie and his friends, bringing him out of his shell in a surprising way.

Let's Talk About Love Charlie nurses an unrequited crush on Sam throughout most of the story, culminating in a tender moment in Sam's bedroom where they contemplate the nature of love. "Why do I and everyone I love pick people who treat us like we're nothing?" Sam asks. "We accept the love we think we deserve," Charlie answers. The ensuing moment, in which Charlie's long-forgotten secret comes to the forefront, is perhaps the most heartbreaking of all.

We Are Infinite In a lovely scene that brings the narrative full circle, Charlie stands atop the bed of Sam's pickup truck, arms aloft, as they barrel across a twinkling bridge. "And in this moment, I swear we were infinite," Charlie says, reciting the novel's most famous line and giving goose bumps to fans everywhere.

The 2012 MTV Movie Awards are officially under way! Stick with MTV News for minute-by-minute coverage, and don't forget to go to MovieAwards.MTV.com to cast your vote for Best Movie!