DOCTOR: I tolerate this century, but I don't enjoy it. Have you ever thought what it's like to be wanderers in the fourth dimension? Have you? To be exiles? Susan and I are cut off from our own planet, without friends or protection. But one day we shall get back. Yes, one day. One day.

SUSAN: The TARDIS can go anywhere.

BARBARA: TARDIS? I don’t understand you, Susan.

SUSAN: Well, I made up the name TARDIS from the initials, Time And Relative Dimension In Space. I thought you’d both understand when you saw the different dimensions inside from those outside.

IAN: Just let me get this straight. A thing that looks like a police box, standing in a junkyard, it can move anywhere in time and space?

SUSAN: Yes.

DOCTOR: Quite so.

IAN: But that’s ridiculous.

SUSAN: Yes, I can see red turns to blue, Mister Chesterton, but that’s because we’re dealing with two inactive chemicals. They only act in relation to each other.

IAN: But that’s the whole point of the experiment, Susan.

SUSAN: Yes, it’s a bit obvious, isn’t it? Well, I’m not trying to be rude, but couldn’t we deal with two active chemicals? Then red could turn blue all by itself and get on with something else? I’m sorry, it was just an idea.

SUSAN: Grandfather!

DOCTOR: It's still a police box. Why hasn't it changed? Dear, dear, how very disturbing.

DOCTOR: If you could touch the alien sand and hear the cries of strange birds and watch them wheel in another sky, would that satisfy you?

DOCTOR: Fear makes companions of all of us.

IAN: Susan Foreman? She your problem too?

BARBARA: Yes.

IAN: You don't know what to make of her?

BARBARA: No.

IAN: How old is she, Barbara?

BARBARA: Fifteen.

IAN: Fifteen. She lets her knowledge out a bit at a time so as not to embarrass me. That's what I feel about her. She knows more science than I'll ever know. She's a genius. Is that what she's doing with history?

BARBARA: Something like that.

DOCTOR: You wanted advice you said. I never give it, never. But I might just say this to you. Always search for truth. My truth is in the stars and yours is here.

DOCTOR: As we learn about each other, so we learn about ourselves.

IAN: I think you should go and apologise to Barbara at once.

DOCTOR: I'm afraid we have no time for codes and manners.

DOCTOR: Rash action is worse than no action at all, hmm?

DOCTOR: I don’t believe that man was made to be controlled by machines. Machines can make laws, but they can not preserve justice. Only human beings can do that.

DOCTOR: But you can't rewrite history! Not one line!

SUSAN: You’re monsters. All of you, monsters. Oh, Grandfather. Grandfather.

SUSAN: Hey, Barbara.

BARBARA: Just the thing for the Royal Enclosure at Ascot.

SUSAN: I’m rather mad about being handmaiden to a goddess.

BARBARA: Well, I must admit that this end of it isn’t too hard to take, either.

SUSAN: Isn’t that beautiful?

BARBARA: You know, that’s what gets me. I mean, take Autloc. He’s sensitive, intelligent. And then there’s

SUSAN: Tlotoxl. It’s incredible, isn’t it? Beauty and horror developing hand in hand.

SUSAN: Well, how will I know?

AUTLOC: Know what?

SUSAN: Well, that he’s to be my future husband.

AUTLOC: You’ll be told.

SUSAN: Told? I’m not going to be told who to marry.

AUTLOC: What say have you in the matter?

SUSAN: It’s my life, I’ll spend it with whom I choose, not someone picked out for me.

DOCTOR: My dear girl, the one purpose in growing old is to accumulate knowledge and wisdom, and to help other people.

SUSAN: So I’m to be treated like a silly little child.

DOCTOR: If you behave like one, yes.

SUSAN: Oh, look, Grandfather. I understand the Sensorites. They’re timid little people. Because their minds and mine can communicate sometimes, they trust me.

DOCTOR: Yes, and I assure you we shall make good use of that fact, but not without discussions. You will not make decisions on your own accord. Now, do you understand? Is that quite clear? Well, is it?

SUSAN: Look, I’m not saying I’m as clever as you, of course I’m not. But I won’t be pushed aside. I’m not a child anymore, Grandfather. I’m not.

DOCTOR: Oh, Susan, Susan.

DOCTOR: Most extraordinary. He ran away from me!

SUSAN: (laughs) That must have looked funny. Flip, flap, flip, flap.

DOCTOR: I can assure you he was very mobile, my child. Come along, let’s get into the First Elder’s room. Come along.

SUSAN: I was going to say, why do you trust your people?

1ST ELDER: Why do you want to make me doubt them?

SUSAN: Trust can’t be taken for granted. It must be earned. I trust you, but only because I know you.

1ST ELDER: But Susan, our whole life is based on trust.

SUSAN: Yes, and that might be your downfall. Look you don’t trust the ground you walk on until you know it’s firm, do you. So why trust your people blindly?

1ST ELDER: When I listen to you, you who are so young among your own kind, I realise that we Sensorites have a lot to learn from the people of Earth.

SUSAN: Grandfather and I don’t come from Earth. Oh, it’s ages since we’ve seen our planet. It’s quite like Earth, but at night the sky is a burned orange, and the leaves on the trees are bright silver.

1ST ELDER: My mind tells me that you wish to see your home again, and yet there is a part of you which calls for adventure. A wanderlust.

SUSAN: Yes. Well, we’ll all go home some day. That’s if you’ll let us.

1ST ELDER: I think I will.

SUSAN: When will we get back, Grandfather?

DOCTOR: I don’t know, my dear. This old ship of mine seems to be an aimless thing. However, we don’t worry about it, do we? Do you?

SUSAN: Sometimes I feel I’d like to belong somewhere, not just be a wanderer. Still, I’m not unhappy.

DOCTOR: Good, good.

SUSAN: Barbara, I’ve got an idea.

BARBARA: What?

SUSAN: He’s quiet now, but we can’t be sure the Sensorites won’t make him help them. Look, if they can use their brains, why can’t we use ours?

BARBARA: To defend him?

SUSAN: Yes, and ourselves. Grandfather and I landed on a planet once called Esto. The plants there used thought transference. If you stood in between two of the plants, they set up a sort of screeching noise. Grandfather said it was because they were aware of another mind.

BARBARA: Breaking in on their communications.

SUSAN: Yes, exactly. I thought if we both tried together.

SUSAN: Isn't' it a better thing to travel hopefully than arrive?

DOCTOR: I don’t make threats, but I do keep promises.