Nardole: Don't die. Because if you do, I think everybody in the universe might just go cold.
Twelfth Doctor: Can't I ever have peace? Can't I rest?
Bill Potts: Of course you can.
Nardole: It's your choice.
Bill Potts: Only yours.
First Doctor: You've saved him!
Twelfth Doctor: Both of them. Never hurts - a couple fewer dead people on the battlefield.
First Doctor: So that's what it means to be a doctor of war.
Twelfth Doctor: You were right, you know. The universe generally fails to be a fairy tale... but that's where we come in!
Twelfth Doctor: It never happened again. Any war, anywhere... but for one day, one Christmas, a very long time ago... everyone just put down their weapons, and started to sing. Everybody just stopped. Everyone was just kind.
Captain: One thing you could possibly do for me, if you were very kind?
First Doctor: Oh, anything. Name it.
Captain: My family. Perhaps you could look in on them, from time to time?
First Doctor: We should be delighted. What's the name?
Captain: Lethbridge-Stewart. Captain Archibald Hamish Lethbridge-Stewart.
First Doctor: I shall make it my business.
Twelfth Doctor: You can trust him on that.
First Doctor: What's so important about one captain?
Twelfth Doctor: Everybody's important to somebody, somewhere.
Twelfth Doctor: You know what? You're a bit of a legend these days... but not everyone believes it. People don't think that it could happen. That someone like you could turn against your own kind. Because your kind don't do that. Because people don't believe there could be any such thing... as a good Dalek.
Dalek: I am not a good Dalek. You are a good Dalek.
Bill Potts (to 12th): You're an arse. Do you know that? You're a... You're a stupid bloody arse.
First Doctor: If I hear any more language like that from you, young lady, you're in for a jolly good smacked bottom.
Twelfth Doctor: Can we just pretend that that never happened?
Bill Potts: I'm a broad-minded girl - I mean, I know we have this whole professor/student thing going on...
Twelfth Doctor: Can we never, ever talk about this again?
Bill Potts: I hope we talk about it loads. I hope we spend years laughing about it.
The Testimony: He is the Doctor of War.
First Doctor: What... What was that?
Twelfth Doctor: To be fair, they cut out all the jokes.
First Doctor: Who the hell do you think you are?
Twelfth Doctor: The Doctor.
First Doctor: I am the Doctor. Who you are, I cannot begin to imagine.
The Testimony: Then let us show you, Doctor. See who you will become. Doctor! Exterminate! You will be assimilated.
Twelfth Doctor: No. No, that's not a good idea!
The Testimony: They all died. The Doctor has walked in blood through all of time and space. The Doctor has many names... the destroyer of the world... The Imp of the Pandorica, the Shadow of the Valeyard, the Beast of Trenzalore, the Butcher of Skull Moon, the Last Tree of Garsennon, the Destroyer of Skaro. He is the Doctor of War.
Twelfth Doctor: You're absolutely right. I should have noticed that.
First Doctor: Well, it might help if you could see properly! (takes 12th's sonic sunglasses of)