We're thrilled to have Maisie Williams joining us on Doctor Who. It's not possible to say too much about who or what she's playing, but she is going to challenge the Doctor in very unexpected ways. This time he might just be out of his depth, and we know Maisie is going to give him exactly the right sort of hell.

I stole your childhood and now I’ve led you by the hand to your death. But the worst thing is, I knew. I knew this would happen. This is what always happens. Forget your faith in me. I took you with me because I was vain. Because I wanted to be adored. Look at you. Glorious Pond, the girl who waited for me. I’m not a hero. I really am just a mad man in a box. And it’s time we saw each other as we really are. Amy Williams, it’s time to stop waiting.

Writing for adults often means just increasing the swearing - but find an alternative to swearing and you've probably got a better line.

When man invented fire, he didn't say, "Hey, let's cook." He said, "Great, now we can see naked bottoms in the dark.

The story of Sherlock Holmes, on the surface, is about detection, but in reality, it's about the best of two men who save each other - a lost, washed-up war hero and a man who could end up committing murders instead of solving them. They come together. They become this perfect unit. They become the best friendship ever, and they become heroes. That's what we fall in love with, not Sherlock on his own. No one can love that man on his own, but Sherlock Holmes and Dr. Watson - the best friends ever.

I never go online. The Internet stuff is bonkers. You must not look at it.

The universe is big, its vast and complicated, and ridiculous. And sometimes, very rarely, impossible things just happen and we call them miracles. And that's the theory. Nine hundred years, never seen one yet, but this would do me.