Michelle Trachtenberg

LOS ANGELES (Zap2it.com) - Michelle Trachtenberg ("Buffy the Vampire Slayer") isn’t the one who makes "The Dive From Clausen’s Pier" in her Lifetime movie premiering Monday, July 25.

She’s taking a major leap of another kind, however. In short, Buffy’s little sister is growing up.

Adapted from a best-selling novel, "Dive" casts 19-year-old Trachtenberg as Carrie Beal, who plans to break off her engagement to her childhood sweetheart, Mike (Will Estes, "American Dreams"), after a Memorial Day picnic with friends that opens the movie. At the lakeside gathering, however, Mike makes an ill-advised dive into shallow water, resulting in paralysis. Confused over whether she should stay in a relationship she had planned to end, Carrie bolts from her Wisconsin hometown to New York, where she quickly falls into an affair with an older man (Sean Maher, "Brian’s Song") with some complex personal issues of his own.

Best known for her TV series work as high-maintenance kid sister Dawn in the cult hit "Buffy the Vampire Slayer," Trachtenberg says she relished playing Carrie, a young woman going through a painful passage in her life even as the actress herself is making a professional transition into more adult roles such as this one.

"What attracted me to Carrie is that she is so flawed and realistic," Trachtenberg says. "She has problems that people deal with on a daily basis. I don’t mean everyone has a fiance who is suddenly in a life-threatening accident, but everyone has to make sacrifices and choices in her life.

"Carrie is closer to me in maturity level than other characters I’ve played in the past. I was attracted to her strengths and the way she handles the situations she finds herself in. It takes a lot of guts to leave everything you know and go out on a limb."

The role also calls upon the actress to play some tasteful but sexy love scenes with Maher and Estes, and she says she’s ready to leave behind those naive teens she has played so successfully to date.

"It feels very natural and organic for me to play a character like Carrie right now, because I’m not a 15- or 16-year-old anymore with huge insecurities," she says. "I know how to talk to boys. I appreciate parts like ’Ice Princess’ and other past roles, but Carrie is sort of a transitional character, testing out the waters, seeing if I felt comfortable being more mature. It’s actually sort of a relief not to have to try to remember again how it felt the first time I walked into a high-school gym and all the boys looked at me. That was me in the past, while Carrie is much closer to me now."

While other former child actors often hit a wall when they try to start playing adult characters, Trachtenberg says she’s pretty confident the hardest part already is behind her.

"I was watching that VH1 special the other day on child stars and ’where are they now?’ and I realized that I already have successfully passed that child star level, which is something I’m incredibly grateful for," she says. "But it hasn’t come without a lot of work. I’ve worked very, very hard to have people know that I’m the age that I am and have whatever talents I have."

"I’m not one to have a big ego. I’ve never been one to understand actors who go, ’Oh, I won’t go in and meet with those people or audition.’ Hey, you do what you have to do to get to the level you want to be at."

One filmmaker who noticed is Gregg Araki, who cast Trachtenberg in "Mysterious Skin," a disturbingly beautiful low-budget drama that is earning rave reviews from critics. Trachtenberg plays Wendy, the best friend of the leading character played by Joseph Gordon-Levitt ("Third Rock From the Sun"), a troubled teenage hustler who carries some horrifying emotional scars from his childhood.

"With ’Mysterious Skin,’ it was just so great to be there, even though nobody was getting paid anything," she says, laughing. "I drive an SUV, so I was barely paying for my gas outlay, since this was during a period in L.A. when it cost $75 to fill your tank.

"We were all there for the love of the story, and I think you can see it there on the screen. We all actually liked one another and wanted to bring this story to life.

"It’s funny, because Joe [Gordon-Levitt] and I have a really similar relationship in real life, although we’re definitely not as screwed up as the characters are on-screen. We’re sort of like an old married couple, very close, and we can really relate to one another intellectually. What’s amazing about that is that we hadn’t met each other before we started working together. You can’t tell that from what’s on-screen, and I’m very proud of that."

Trachtenberg has several new projects in development, including an indie film in which she will serve as a first-time producer.

"That’s ’Hooking Up,’ which is an empowering story of a girl who experiences something very traumatic and how she goes about dealing with it and finding herself again," she says. "That’s pretty much all I can say right now, but I’m thoroughly enjoying being a producer. It’s not just a vanity credit. I’m all about location scouting and understanding budgets and all the little details."

Also on her to-do list: conquering an old phobia by doing a play in New York and, eventually, going to film school, although she’s getting quite an on-set education until then.

And, of course, whenever she can she continues her anti-drug crusade, a commitment that led Teen People to name her one of "20 Teens Who Will Change the World."

"I’m incredibly passionate about keeping kids off drugs," she says. "I’ve always been firmly convinced that you can be successful without using drugs. Certainly I’m almost 20 and I’ve never used a drug to advance a career that I think of as pretty successful. I want to show kids out there: Look. You can be successful and go about your life in a normal way without having a crack pipe in your mouth."