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When the long-awaited final "Twilight" installment, " Breaking Dawn: Part 2," premieres in Los Angeles tonight, fans will get their first glimpse of the newest vampire, Mary, played by up-and-comer Toni Trucks.

"I don't think people will be disappointed," Trucks told ABCNews.com about the final film in the franchise, while refusing to give away any spoilers.

Trucks, 32, previously worked with "Breaking Dawn" director Bill Condon in "Dreamgirls" before she was cast as Mary, a lone vampire who is enlisted into the Cullen vampire family circle to protect Bella and Edward's new baby after the rival Volturi coven declares war on them.

"She truly is a solo vampire," Trucks said of her character. "She comes in because she believes in the fight, but she won't be back for the holidays. She's a badass."

Though Trucks won't be back either, she said "Twilight" fans, or Twilighters, have been completely receptive to her joining the franchise for the final film.

Attending the first 'Twilight" convention a year ago in England, she said, "When they announced my name, I was overwhelmed by cheers and screams." Now she even has her own fan base; they call themselves "Toni's Truckers."

She said the same fans will stick by the film's stars, Kristen Stewart and Robert Pattinson, who have weathered a scandal in which she was accused of cheating on him.

'Twilight' Stars Then and Now

"We're not going to see any negativity," Trucks predicted. "The fans are so loyal to them and think they can do no wrong. They just love them so deeply from such an innocent place."

Working with Pattinson and Stewart, attending "vampire camp," where she learned to fight, and getting outfitted as a vampire - down to her own specially designed red contact lenses - was a very different experience from Trucks' role in the indie romantic comedy "Ruby Sparks" with Paul Dano and Zoe Kazan. The film was shot after "Breaking Dawn" but released earlier this summer.

"I was thrilled to be cast in 'Ruby Sparks.' Though it doesn't have the notoriety of 'Twilight,' I was working with the directors of 'Little Miss Sunshine,' as well as Annette Bening and Paul Dano," she said. "Then to be able to do TV afterward, I feel very lucky to work across the lines like that on such wildly different things."

Trucks was referring to her role as the wisecracking assistant/best friend Cyndi Vega on the short-lived CBS legal drama "Made in Jersey."

Though CBS pulled the show after airing the second episode, the remaining six episodes will air beginning Nov. 24 through December.

"I'm trying to come to a place where I can enjoy the highs, because inevitably TV shows end and films end," she said. "I really feel so excited and thankful to be in such great company."