The following quote is taken from The End of Time, Part II which was originally broadcast on January 01, 2010. It is the saddened final appearance, to date, of the Tenth Doctor. The scene is between The Tenth Doctor and Wilfred Mott and serves and answers the prophecy – He Will Knock Four Times.
The End of Time, Part II
The Doctor: I’m alive! I’ve… There was… I’m still alive!
Wilf: They’ve gone, then? Good-oh. If you could let me out?
The Doctor: Yeah…
Wilf: Only, this thing seems to be making a bit of a noise…
The Doctor: The Master left the nuclear bolt running. It’s gone into overload.
Wilf: And that’s bad, then, is it?
The Doctor: No, because the excess radiation gets vented inside there. Vinvocci glass. Contains it. All 500,000 rads, about to flood that thing.
Wilf: Oh… well you’d better let me out then!
The Doctor: Except it’s gone critical. Touch one control, and it floods. [The Doctor looks at his sonic screwdriver] Even this would set it off.
Wilf: I’m sorry.
The Doctor: Sure.
Wilf: Look, just leave me.
The Doctor: OK, right, then, I will. Because you just had to go in there, didn’t you? You had to go and get stuck, oh yes! Because that’s who you are, Wilfred! You were always this. Waiting for me all this time!
Wilf: Oh, really, just leave me. I’m an old man, Doctor, I’ve had my time.
The Doctor: Well, exactly, look at you. Not remotely important. But me… I could do so much more! So much more! But this is what I get, my reward. And it’s not fair!
Oh…lived too long.
Wilfred. It’s my honour. Better be quick: three, two, one…
What is your favorite quote form Doctor Who?