Shadow

“I travelled across the world. From the ruins of New York, to the fusion mills of China, right across the radiation pits of Europe. And everywhere I went I saw people just like you, living as slaves! But if Martha Jones became a legend then that's wrong, because my name isn't important. There's someone else. The man who sent me out there, the man who told me to walk the Earth. And his name is The Doctor. He has saved your lives so many times and you never even knew he was there. He never stops. He never stays. He never asks to be thanked. But I've seen him, I know him... I love him... And I know what he can do. - Martha Jones”
― Russell T. Davies

“Cyber Leader: Daleks, be warned. You have declared war upon the Cybermen.
Dalek Sec: This is not war - this is pest control!
Cyber Leader: We have five million Cybermen. How many are you?
Dalek Sec: Four.
Cyber Leader: You would destroy the Cybermen with four Daleks?
Dalek Sec: We would destroy the Cybermen with one Dalek! You superior in only one respect.
Cyber Leader: What is that?
Dalek Sec: You are better at dying.”
― Russell T. Davies

“The Doctor: Oh, now what's this, then? I love this. A big, flashy-lighty thing. That's what brought me here. Big, flashy-lighty things have got me written all over them. Not actually, but give me time... and a crayon.”
― Steven Moffat

“When you run with the Doctor, it feels like it'll never end. But however hard you try you can't run forever. Everybody knows that everybody dies and nobody knows it like the Doctor. But I do think that all the skies of all the worlds might just turn dark if he ever for one moment, accepts it. Everybody knows that everybody dies. But not every day. Not today. Some days are special. Some days are so, so blessed. Some days, nobody dies at all. (In the library, the Doctor walks back to the TARDIS. He stops, looking at the doors. Then he raises his hand, and stands there poised like that for a long moment. Finally he snaps his fingers. The doors open. He smiles slowly and walks in, joining Donna. Then he snaps his fingers again, and the doors close. River's voice continues over this.) Now and then, every once in a very long while, every day in a million days, when the wind stands fair, and the Doctor comes to call... everybody lives.”
― Steven Moffat