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.

Rose Tyler: Can't you come through properly? The Doctor: Then the whole thing would fracture. The two universes would collapse. Rose Tyler: So?

Daleks: [simultaneously] Exterminate! Exterminate! [They fire their weapons, none of which so much as touch the Doctor] The Doctor: Is that it? Useless! Nul points! [to Rose and Jack] It's all right, you can come out; that forcefield can hold back anything! Jack Harkness: Almost anything. [pause] The Doctor: Yes, but I wasn't going to tell them that. Thanks.

I saw the Fall of Troy! World War Five! I was pushing boxes at the Boston Tea Party! Now I'm gonna die in a dungeon.... [disgustedly] in Cardiff!

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.

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

Rose: My mum's here. The Doctor: Oh, that's just what I need! Don't you dare make this place domestic! Mickey Smith: You ruined my life, Doctor. [the Doctor turns and looks at him, irritated] They thought she was dead, I was a murder suspect because of you! The Doctor: [looks at Rose] See what I mean? Domestic! Mickey: I bet you don't even remember my name! The Doctor: Ricky. Mickey: It's Mickey! The Doctor: No, it's Ricky. Mickey: I think I know my own name! The Doctor: You think you know your own name? How stupid are you?