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.

Twitter! It's like being stalked by committee!

I'm quite happy to leave it still feeling that way, leave it before it starts feeling like a job. ... I have such fond memories of watching 'Doctor Who' when I was a kid and growing up, that if I've left anybody anywhere with memories as fond, then I feel like I've done my job.

It's very hard to be objective about something you're in, especially when you set it up against things that you experienced as a child.

I think if my eight-year-old self could see me at the Royal Albert Hall winning a prize for playing the Doctor on telly, he would need a stiff shot of Irn-Bru.

An accent has to do with the way your mouth works and the sounds that come out of your head, but somehow it informs everything about you.

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.