"The first two films are about the strength of everything, the strength of relationships, of how Harry sees everything," Radcliffe says. "The fourth film is very much about all of that weakening and starting to disintegrate, so Harry's relationship with Ron is very shaky for a lot of the film."

"To some extent, they've always sort of played down how I look in the films and suddenly they wanted this Julia Roberts, pretty woman-esque moment, and it was really good fun," she says.

"I don't think any of this could get old, that was sort of the question everyone asked on the red carpet when I did the "Goblet of Fire" premiere," she said. "I don't think you can ever get used to millions and millions of, I don't know how many people there were outside of that cinema. It's still new and exciting every single time, and I think for me what keeps me really interested is the fact we've had a new director every single time round."