I always like seeing people transforming themselves, in whatever way that might be, and a different accent is part of that.

It has to be said that the bad guys are often more interesting than the good guys because you get to indulge part of your nature that hopefully gets subsumed most of the time. But I just like playing interesting characters, and variety's the spice of that, as it is with life, I suppose.

I've always been a geek and slightly awkward… slightly umm… I was never the cool kid at school.

When you're playing a real person there's a balance between playing the person in the script and playing the person as he was in life. You have to be respectful and true to who that person was, but at the same time tell the story in the film.

Getting the call to be in The Goblet of Fire was like being welcomed into the most exclusive upper circle of some elite actors' club. You sit on set with the cream of the National Theatre and the RSC, all clutching wands or wearing witches' hats.

And the very fact of how you speak somehow influences who you are. The way you move, the way you think, it seeps into your being, and it's quite hard to really break that down entirely.

Moths are the ones that freak me out. It's something to do with the way that, if they get squashed, they turn to dust. There's something very wrong about that. It all feels a bit Gothic.