ET sits down with Dakota Fanning, Jamie Campbell Bower, Michael Sheen and Cameron Bright from 'The Twilight Saga: New Moon.'

The foursome play members of the ruling vampire clan, the Volturi in the sequel to 'Twilight,' and they open up about their characters' evil intentions.

Veteran stage actor Michael Sheen says of playing his diabolical 2,000-year-old character, "I like the idea of someone who thinks of himself as a nice, sweet grandmotherly type but who's actually a psycho killer underneath. ... So, I like the idea of playing someone who is sort of soft, quite loving and thinks of himself as being very sentimental and then likes to pull people's heads off."

Dakota Fanning has a long history of playing nice girls, and tells ET, "It was the first time playing an evil character, but that was one of the reasons why I wanted to do it. It's more fun playing bad girls, more fun than playing good girl."

Michael says of the 'Twilight' series in general, "What's wonderful about these stories, I think, is that there are very fantastical elements, and supernatural elements, and magical elements, and at the same time, it's very moving and touching and it really seems to speak to people's hearts. So it's really wonderful to be in these films."

Watch the video for more, and also check out photos from the set of 'New Moon'! Come back Monday to see ET's extended interview with the Cullen women: Ashley Greene, Nikki Reed and Elizabeth Reaser, and come back every weekday until 'New Moon' premieres in theaters on Friday, November 20 to see a new ET video with the cast!