We're going to see you in "Harry Potter and the Deathly Hallows" as Gellert Grindlewald, joining Rob as the only actor to have a foot in both of these phenomenally huge franchises. Have you guys bonded over this?
Campbell Bower: Well, Rob is quite a significant character in the "Potter" movies, I believe, from what I can remember. My character is a bit smaller.

Have you and Rob discussed things he learned as he tried to go from one franchise to the other? Did he have pointers for you?
Campbell Bower: No. There isn't much difference between them, apart from the story. They're both massive franchises, and they both work like a machine, you know? Everyone's on time, and everyone's doing the best job that they can.

Some people might say that "Twilight" is more for girls, while boys enjoy "Potter" more. Would you agree?
Campbell Bower: I'd say that they've both got fairly specific fanbases. "Twilight" is more for your 13- to18-year-olds, although there are people who obviously enjoy it — older people — which is great. But I think the main audience is the 13- to 18-year-olds, maybe because of Rob and the fact that they love Edward. [As for] "Harry Potter," it's a bit younger. Although the recent films are a bit dark. I saw [a "Potter" film] the other day, and I thought it was quite scary. You've also got your older audience [there].

What's the difference between how you approach each franchise?
Campbell Bower: Like, am I playing them the same? No, I mean, they're two different characters, they're two different people. [To play them the same] would be like, "I've just eaten some cheese, and now I'm eating an apple, and it tastes like cheese." When you're filming anything, you've just got to believe in the character and believe yourself that you are the character.

"I play Gellert Grindelwald, who is an old friend of Dumbledore's," explained the 21-year-old actor. "It's a flashback character, which is good fun. I did a little bit before I went off and did 'New Moon.'"

"No, I'm just doing number one," he answered when we asked if Grindelwald was scheduled to be in both halves of the split-for-the-cinema-sequels made from J.K. Rowling's "Harry Potter and the Deathly Hallows" novel. "Thus far, I mean. I haven't seen the script for the second one; I don't think anyone has seen the script for the second one."

As for the look of Gellert, the actor revealed: "We're pretty much keeping it straight; the costume is fantastic — we had this idea that he's very bird-like. He's described in the book as almost looking like a crow or something like that, and we [latched] onto that; I have a nice jacket which makes me look cool."

"It doesn't have wings or anything; it's just the way that it's cut. It's very subtle," he explained. "But, as is true with a lot of things in film, if you know what the intention is and the background of it, then you can recognize it — but if you're not really watching or paying any attention, then you'll miss it."