You know when sometimes you meet someone so beautiful — and then you actually talk with them, and five minutes later they're as dull as a brick. But then there's other people, and you meet them and you think: "Not bad, they're okay," and then you get to know them, and their face sort of becomes them, like their personality's written all over it; and they just — and they turn into something so beautiful.

Reinette: One may tolerate a world of demons for the sake of an angel.

Madame Kovarian: The anger of a good man is not a problem. Good men have too many rules. The Doctor: Good men don't need rules. Today is not the day to find out why I have so many.

What is immutable about Sherlock Holmes? He favors reason over emotion, but actually underneath that, there is a lot of emotion going on. You can't suddenly make him ordinary because he would hate that. He's not suddenly going to be somebody else.

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.

It's a TV show. Only the emotional damage is real.

Kathy Nightingale: What's good about sad? Sally Sparrow: It's happy for deep people.