Back in 2005, when I was Christopher Eccleston, we saw one of the largest increases on record, of CO2 in the atmosphere. Unless we keep the rise in global temperature to under 2 degrees, by the time I'm Daniel Radcliffe or wee Jimmy Crankie, I won't be able to save the planet. I won't be here to help you -- well I might, but I'll be that bloke who won Any Dream Will Do.

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 remember a conversation with my parents about who the people on the TV were, and learning they were actors and they acted out this story and just thinking that was the most fantastic notion, and that's what I want to do.

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.

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.

Twitter! It's like being stalked by committee!

All roads seem to have come back to Doctor Who in our life. But, no, it was a huge part of my growing up. I was a massive fan and it certainly inspired me to get into acting and to be ... one of those people that tells stories on TV. That was a huge part of my childhood.