The Doctor: Can I borrow your horse, please? It's official marshal business.
The Preacher: He's called Joshua. It's from the Bible. It means 'The Deliverer.'
The Doctor: No, he isn't.
The Preacher: What?
The Doctor: I speak horse. He's called Susan. And he wants you to respect his life choices.
Rory Williams: Uh, the sign does say 'keep out.'
The Doctor: I see 'keep out' signs as suggestions more than actual orders. Like 'dry clean only.'
[discussing why someone wants to kill The Doctor in a town that they've only just arrived at. ]
Amy Pond: What does he want? Has he issued some kind of demand?
Isaac: Says he wants us to give him the alien doctor.
Amy Pond: [to The Doctor] But that's you. Why would he want to kill you? Unless he's met you.
Amy Pond: What's happened to you, Doctor? When did killing someone become an option?
The Doctor: Jex has to answer for his crimes.
Amy Pond: And what then? Are you going to hunt down everyone who's made a gun, or a bullet, or a bomb?
The Doctor: But they keep coming back, don't you see? Everytime I negotiate, everytime I try to understand. Well, not today. No. Today, I honor the victims first. His, the Master's, the Daleks', all the people who died because of MY mercy!
Amy Pond: See, this is what happens when you travel alone for too long. Well, listen to me, Doctor, we can't be like him. We have to be better than him.
[Amy has just accidentally shot a gun twice while waving it about as she's talking]
Isaac: Everyone who isn't an American, drop your gun!
Shipboard Computer: Thank you for choosing Abraxas Security Software: incinerating intruders for three centuries.
The Doctor: What happens if someone crosses the line?
Isaac: [throws him a hat with a bullet hole through it]
The Doctor: Well, not a very good shot, then.
Isaac: He was aiming for the hat.
The Doctor: [Incredulous] He shoots people's hats?
The Doctor: [to the barmaid] Tea. But the strong stuff. Leave the bag in.
The Doctor: Okay, so, our next trip... Oh! You know all the monkeys and dogs they sent into space in the 1950s and 1960s? You will never guess what really happened to them.
Rory Williams: So, what do we do with Jex?
Isaac: "What do we do with him"?
Rory Williams: Yeah. I mean, he's a war criminal.
Isaac: No, he's the guy who saved the town from cholera. The guy who gave us heat and light.
Amy Pond: Look, Jex may be a criminal, and yeah, kinda creepy -...
Kahler-Jex: ...And still in the room.