Amy Pond: 'I thought... well, I started to think you were just a madman with a box.' The Doctor: 'Amy Pond, there's something you better understand about me, 'cause it's important and one day your life may depend on it. [He Smiles] I am definitely a madman with a box.

I think of myself as a writer with a sense of humour rather than a comedy writer. Happy to tell a story with lots of jokes in it - I wouldn't know how to do jokes without the story.

If you don't expect to like someone and then you do, that's an incredibly exciting moment.

You want weapons? We're in a library! Books! The best weapons in the world!

The Doctor: I've seen bigger. Clara: Really? The Doctor: Are you joking? It's massive!

We have a plan to top it. And I do think our plan is devastating. We’ve practically reduced our cast to tears telling them the plan … we’re probably more excited that we’ve ever been about Sherlock.

What's the point of being a grown-up if you don't get to be immature?