The Air I Breathe is loosely based on a Chinese proverb which lists happiness, pleasure, sorrow, and love as the four key emotions that connect all humanity. ‘Happiness’ is brought to life on the screen by Oscar-winner Forest Whitaker. Brendan Fraser takes on the job of playing out the ‘Pleasure’ part of the story. Kevin Bacon is ‘Love’ and Sarah Michelle Gellar (The Grudge) is ‘Sorrow’, playing a pop star named Trista being held captive by a mob boss who rules the roost.

Think Babel or Crash and you have an idea of the multi-narrative storytelling involved in The Air I Breathe.

Playing a pop singer gave Gellar a chance to draw on her own encounters with the media and fans. “There are certain things that I have understood that I have experienced firsthand and at the same time, she was based on a real person that Jieho [Lee, writer/director] knew so a lot of it was Jieho's experience. What's interesting is to take my firsthand experience compared with what Jieho saw as an outsider and put them together,” explained Gellar. “We were sort of like the two people together making that happen.”

Gellar understood and could relate to much of what her character, Trista, was experiencing. She was only 18 when Buffy the Vampire Slayer exploded and it took her some time to figure out who she was outside of the public’s image of her. “As an actor, you constantly play these other characters. You're always pretending to be somebody else, but at the same time you have to keep a handle on who you are,” offered Gellar.

“I think that's where a lot of actresses get lost sometimes, because that's tough. I can only imagine it has to be the same as a pop star because you're not even playing a character. You're a persona.”

“You look at somebody like Gene Simmons. He really walks that balance so well. He knows when he's on stage who he is, but he knows who he is at home and they're not the same person. I give him a lot of credit for that because it's really hard. I think that’s where Trista was learning how to grow. What's so interesting specifically about Trista in this movie, yes I was ‘Sorrow’ and that was the emotion that I was there to experience, at the same time, she's the one that grows the most from learning about pleasure, happiness and love.”

Gellar did seven season of Buffy the Vampire Slayer and has been in big budget movies, but the indie world is special to the Golden Globe nominated actress. “To be in a cast like this, to have the experience that we had… It wasn't just so much the beauty of the script but there we were, we were in Mexico City all of us, in one hotel. At the end of the night, you're just hanging at the bar and there's Brendan Fraser and Andy Garcia and Kevin Bacon. You're like, ‘Is this my life?’ Then especially in a story like this where there's so much emotion and so much trust that has to come between the actors to have that camaraderie, those experiences, there's no question that it's different. I guess what the difference is is everyone there does this because they love it,” said Gellar. “Nobody was there, I promise you, to earn a paycheck. I think we all wound up owing money by the time we were through. But you do it because you love it and because of the experience.”

Gellar said her time spent working on The Air I Breathe was unparalleled in terms of the cast and the overall experience. “I'm 10 times the actor for having worked with this cast,” confessed Gellar. “First of all, pretty much being the only girl among those guys…guys might not appreciate it but for me, that's a pretty good gig. Just to raise your game that level, I don't know. I feel very lucky.”

After being the lead in an action-heavy TV series, Gellar says it’s definitely nice to be able to do something less high profile where she’s free to just act. “It's been great. One of the things when I was on the show, the one thing I was very lucky about was I was always fulfilled. I wasn't playing high school five years later. She was in high school, then she went to college, and then she essentially became a mother. She became a mother for the other slayers. She had tragedy in her life. She had happiness. She [sang], she danced, she was all those things so as an actor I was always challenged. But the roles that I picked on the side to do basically were because of when my hiatus was. ‘Does it fit into the hiatus? Can you make it work?’ Independents don't fit into that time span because if the money doesn't come in by that day and it pushes, I can't do it. I only had this window. So when it was done, those things for the first time I could pick things just because of the experience.”

“Because Buffy gave me all those gifts, I've had the time to sort of go, ‘God, Mexico City, the story,’ and I signed on before the other actors so I didn't even know that it was going to have a cast like this. Because of those experiences, I think that's how you grow personally and professionally. I made four movies last year. You can keep working and you can keep having those outside interests that you lose over the course of eight years on a show. Not saying that it wasn't the most incredible eight years and I wouldn't change a thing.”

Gellar will next be seen in Possession, a thriller based on the Korean film Jungdok. “Basically, it takes place in one house and it's about a young career woman which I hadn't really done, a young lawyer, really focused and meets a guy who hires her to get his brother out of jail,” said Gellar. “They fall in love and get married. They get the brother out of prison, but he has to live with them. He's on parole and she and the brother don't get along. She's a straight-laced black and white lawyer and he's, in her mind, just a criminal. Lee [Pace] plays the brother.”

“You see the family dynamic and then the two brothers are in a terrible car accident. They're both comatose and it follows her for a little bit sort of losing everything she thought she had, what she possessed as important to her in her life. Then she gets a phone call one day that he's woken up. She goes to the hospital and unfortunately it's not her husband, it's the brother. He believes that he's her husband and she has to take him home because [of] no insurance, and it sort of follows what happens when she falls in love with him.”