Steven wrote to me today, saying, 'Don't you feel like sticking your head out of the window and yelling, "I DON'T KNOW WHAT I'M DOING!!!"' Yes, absolutely. Solidarity. Fear is always the same. Different worries with different scripts, but the same baseline fear.

Doctor Who: You want weapons? We're in a library. Books are the best weapon in the world. This room's the greatest arsenal we could have. Arm yourself! (from Tooth and Claw in Season 2)

Harriet Jones: Did you notice when they fart, if you'll pardon the word, it doesn't just smell like a fart, if you'll pardon the word, it's something else. What is it? It's more like, um... Rose Tyler: Bad breath. Harriet Jones: That's it! The Doctor: Calcium decay. Now that Narrows it down!.. Calcium phosphate. Organic calcium. Living calcium. Creatures made out of living calcium. What else - what else? Hyphenated surnames. Yes! That narrows it down to one planet! Raxacoricofallapatorius! Mickey Smith: [sarcastically] Oh yeah, great! We can write 'em a letter.

Anything works, as long as you write it properly.

In the end I sort of though we created a companion who was so alive and dynamic and so wedded to the doctor that you’d need a whole universe to contain her in. The only way to get rid of her is to send her into a parallel world from which she can never return; otherwise she would stay with the doctor forever.

Wilf: God bless the cactuses! The Doctor: That's cactI. Alien: And that's racist!

Captain Jack: Rose, you are worth fighting for. [Jack kisses Rose passionately] Captain Jack: Wish I'd never met you, Doctor, I was much better off as a coward. [Jack kisses the Doctor the same way]