Emma Watson recently chatted with Entertainment Weekly about transitioning from playing Hermione Granger in the Harry Potter film series to her first post-Potter starring role in the adaptation of Stephen Chbosky's The Perks of Being a Wallflower, out in theaters September 21.

Emma discussed how she approached her first go at the American accent, what author, screenwriter, and director Chbosky promised her about the feature, and bonding with her costars, including Logan Lerman and Ezra Miller. That, including a new promo from the drama, and a small teaser about The Bling Ring, can be read below.

Emma Watson: I started as Emma with some Hermione still left in my system. I went through the tunnel [in Pittsburgh] and I came out ready to start something new.

Stephen Chbosky not only wrote the novel The Perks of Being a Wallflower but he wrote the screenplay and directed the film, too. That’s unusual.
Emma: In terms of being true to the book, we couldn’t fail. And that’s a relief. It’s always scary when you know how much something means to other people – you don’t want to mess it up.

How did he persuade you to play Sam, a rebellious and popular high school girl?
Emma: At our initial meeting, he said, "Okay, not only is this going to be one of the most important parts you play, you’re also going to have the summer of your life and meet some of your best friends." I thought, "That’s quite a claim. Who is this guy?" [laughs] Everything he said came true.

I’m assuming it was a fun shoot?
Emma: Who knew Pittsburgh was going to become one of my favourite places in the world? When I first arrived, I was like, "Oh my God, this is going to be awful – we’re here for seven weeks? There’s nothing here!" And then it worked out perfectly. [The cast and crew] all lived together in a hotel, and all the rooms were connected. We ate together every night, played music and games. A lot of barriers come down when you’re living together.

How hard was it to master an American accent?
Emma: Before I started on the movie, I lost a lot of sleep over it, I have to tell you. I’ve watched movies when actors don’t get the accents spot-on, and it immediately takes you out of the moment. So I really felt like I had to get it right. I worked with an amazing voice coach, and we went through every single word and every single syllable and really hammered it.

You recently wrapped Sofia Coppola’s The Bling Ring, where you play a fame-obsessed teen who robs celebrities’ homes.
Emma: I’m partly filled with dread and partly filled with excitement. It’s weird to play this crazy girl. If people find it difficult seeing me with an American accent, wait until they see this.