Filming location: Utah, USA

This episode marks the first time that the production crew of this or the original series have actually filmed an episode in the U.S.

The episode begins with an "in memoriam" to actress Elisabeth Sladen, a long-time Doctor companion, who died four days before this episode premiered.

Mark Sheppard and W. Morgan Sheppard, playing younger and older versions of the same character, are real-life son and father.

The movie that Rory and Amy start watching is Flying Deuces (1939), starring Laurel and Hardy. As members of the French Foreign Legion, they are surrounded by men waring fezzes, explaining the Doctor's interest.

Amy: "The personal intervention of the King, the unnamed Doctor was incarcerated without trial in the Tower of London.
Rory: Okay, but it doesn't have to be him.
Amy: "According to contemporary accounts, two nights later a magical sphere some 20' across was seen floating away from the Tower, bearing the mysterious Doctor aloft."
Rory: Okay, it's him.

Rory: Hey, nice hat.
The Doctor: I wear a Stetson now. Stetsons are cool.

Amy: So what's been happening? Because you've been up to something.
The Doctor: I've been running. Faster than I've ever run. And I've been running my whole life. Now it's time for me to stop.

Rory: So when are we going to 1969?
Amy: And since when do you drink wine?
The Doctor: I'm 1103, I must've drunk it sometime. (spits it out) Oh, white's horrid. I--I--I thought it would taste more like the gum.
Amy: 1103? You were 908 the last time we saw you.
The Doctor: And you've put on a couple of pounds. I wasn't going to mention it.

Amy: You're okay. How can you be okay?
The Doctor: Hey, of course I'm okay. I'm always okay, I'm the King of Okay. Oh, that's a rubbish title, forget that title. Rory the Roman, that's a good title. Hello, Rory.

The Doctor: Now, then, Canton Everett Delaware the Third. That was his name, eh? How many of those can there be? Well, three, I suppose.

The Doctor: I'm being extremely clever up here and there's no one to stand around looking impressed. What's the point in having you all?

The Doctor: Time isn't a straight line, it's all bumpy-wumpy. There's loads of boring stuff, like Sundays and Tuesdays, and Thursday afternoon. But now and then there are Saturdays. Big temporal tipping points when anything's possible. TARDIS can't resist them, like a moth to a flame. She likes a party, so I give her 1969, NASA, because that's space in the 60s. And Canton Delaware Everett III, and this is where she's pointing.

Amy: Trust me.
The Doctor: Okay.
Amy: You have to do this. And you can't ask why.
The Doctor: Are you being threatened? Is someone making you say that?
Amy: No.
The Doctor: You're lying.
Amy: I'm not lying.
The Doctor: Swear to me. Swear to me on something that matters.
Amy: Fish fingers and custard.
The Doctor: My life in your hands. Amelia Pond.

President Richard Nixon: You were my second choice, Mr. Delaware.
Canton Delaware: That's okay. You're my second choice for President, Mr. Nixon.

River Song: Richard Milhouse Nixon. Vietnam, Watergate. Some good stuff, too.
The Doctor: Not enough.
River Song: Hippie.
The Doctor: Archaeologist.

President Richard Nixon: Who are they? And what is that box?
The Doctor: It's a police box, can't you read? I'm your new undercover agent, on loan from Scotland Yard. Code name: The Doctor. (indicates Amy, Rory, River) These are my top operatives, The Legs, The Nose, and Mrs. Robinson.
River Song: I hate you.
The Doctor: No you don't.

Canton Delaware: How'd you get it in here? I mean, you didn't carry it in.
The Doctor: Clever, eh?
Canton Delaware: Love it.
Carl: Do not compliment the intruder!
Canton Delaware: Five minutes?
The Doctor: Five.
Carl: Mr. President, that man is a clear and present danger.
Canton Delaware: Mr. President, that man walked in here with a big blue box and three of his friends. (indicates Carl) And that's the man he walked past. One of them's worth listening to. I say we give him five minutes. See if he delivers.
The Doctor: Thanks, Canton.
Canton Delaware: If he doesn't, I'll shoot him myself.
The Doctor: Not so thanks.

The Doctor: I'm going to need a SWAT team ready to mobilise, street maps covering all of Florida, a pot of coffee, twelve Jammie Dodgers, and a fez.
Canton Delaware: Get him his maps.

The Doctor: Jefferson isn't a girl's name. It's not her name, either. Jefferson, Adams, Hamilton, River!
River Song: Surnames of three of America's Founding Fathers.
The Doctor: Lovely fellows. Two of them fancied me.

The Doctor: And Doctor Song, you've got that face on again.
River Song: What face?
The Doctor: The "he's hot when he's clever" face.
River Song: This is my normal face.
The Doctor: Yes, it is.
River Song: Oh, shut up.
The Doctor: Not a chance.

Amy: Okay, but why would anyone want to trap us?
The Doctor: Ah, let's see if anyone tries to kill us and work backwards.

Amy: But why? If you can make it all the way to Earth, why steal technology that could barely make it to the Moon?
The Doctor: Maybe because it's cooler. Look how cool this stuff is.
Amy: Cool aliens?
The Doctor: Well, what would you call me?
Amy: An alien.

The Doctor: Be careful.
River Song: Careful. Tried that once. Ever so dull.
The Doctor: Shout if you get in trouble.
River Song: Don't worry. I'm quite the screamer. Now there's a spoiler for you.
Canton Delaware: What's going on?
The Doctor: Uhh, nothing. She's just a friend.
Rory: I think he's talking about the possible alien incursion.

The Doctor: Rory, would you mind going with her?
Rory: Yeah. A bit.
The Doctor: Then I'd appreciate it more.
Rory: Hang on, River. I'm coming too.

Rory: What's through there?
River Song: No idea.
Rory: Something bad?
River Song: Almost definitely.
Rory: You're going to open it, aren't you?
River Song: Well, it's locked. How's a girl supposed to resist?
Rory: Is this sensible?
River Song: God, I hope not.

Rory: What did you mean, what you said to Amy? "There's a worse day coming for you."
River Song: When I first met the Doctor, a long long time ago, he knew all about me. Think about that. Impressionable young girl, suddenly this man just drops out of the sky. He's clever and mad and wonderful, and knows every last thing about her. Imagine what that does to a girl.
Rory: I don't really have to.
River Song: Trouble is, it's all back to front. My past is his future. We're travelling in opposite directions. Every time we meet, I know him more, he knows me less. I live for the days when I see him. But I know that every time I do, I'm one step further away. The day's coming when I'll look into that man's eyes, my Doctor, and he won't have the faintest idea who I am. And I think it's going to kill me.