- (5 November - 10 December 1966) — Although this serial marked the first appearance of the Second Doctor, it was the third serial of the fourth season.
- Polly: [inside the TARDIS, the Doctor is regenerating. Ben and Polly watch in amazement as the frail old man changes into a younger figure. Ben and Polly discuss the "new" Doctor lying on the floor of the TARDIS] His face, his hair. Look at it!
- Ben: He's breathing, and the TARDIS seems to be normal.
- Polly: Ben, what are we going to do? We can't just leave the Doctor there.
- Ben: What, him? The Doctor?
- Polly: Well that's who came through the doors - there was no one else outside. Ben, do you remember what he said in the tracking room? Something about "This old body of mine is wearing a bit thin".
- Ben: So he gets himself a new one?
- Polly: Then whatever happened, happened in here.
- Ben: But it's impossible!
- Polly: Not so long ago we'd have been saying that about a lot of things.
- The Doctor: [the Doctor awakens and mutters to himself] Slower. Slower. Concentrate on one thing. One thing. It's over. Hmm, hmm, hmm. It's over.
[The Doctor moves over to the Console, moves a few switches, and dematerialises the TARDIS, proving to Ben and Polly he is indeed The Doctor.]
- Ben: Doctor?
- The Doctor: [the Doctor turns and stumbles over the console. Mutters to himself] The muscles are still a bit tight.
- Ben: What are we gonna do?
- Polly: It is the Doctor. I know it is... - I think.
- Ben: It's not just his face that's changed. He doesn't even act like him!
- [The Doctor explains his regeneration.]
- Ben: The Doctor always wore this. If you are him it should fit... That settles it!
- The Doctor: I'd like to see a butterfly fit into a chrysalis case after it spreads its wings.
- Polly: Then you did change.
- The Doctor: Life depends on change, and renewal.
- Ben: Oh, that's it, you've been renewed, have you?"
- The Doctor: Renewed? Have I? That's it, I've been renewed. It's part of the TARDIS. Without it I couldn't survive.
- The Doctor: [Ben and Polly follow the Doctor into the capsule and find the cobwebbed Daleks] Polly... Ben... Come in and meet the Daleks.
- Ben: What?
- The Doctor: The Daleks.
- The Doctor: If there was a bomb under this floor timed to go off in five minutes, would you ask my permission before you ripped up the floorboards? [Distracted] Ah ha, fruit!
- The Doctor: Now, Lesterson's fanatic. The Governor's jealous of his own position. What does that suggest to you?
- [the Doctor answers himself]
- The Doctor: Dunno. Hadn't thought about it. That all is not well with this colony. Add to that one Dalek!
- Ben: Oh, blimey, you don't half make mountains, don't you? One Dalek?
- The Doctor: [explaining] Yes! All that is needed to wipe out this entire colony.
- The Doctor: Lesterson, what have you done? What have you done?
- Lesterson: I'll show you. Janley, now!
[A Dalek glides into the room. It's movement is strangely fascinating, holding everyone transfixed. Everyone except the Doctor who edges backwards, shaking his head in horror. The Dalek stops and looks around at each person in turn. At last it re-focuses on the Doctor. The Doctor backs into a chair]
- Ben: It recognised the Doctor. It recognised him!
- Polly: What's the matter, Doctor? Are you all right?
- The Doctor: The fools. The stupid fools!
- Ben: You're scared. What can it do?
- The Doctor: Nothing yet.
- Lesterson: This creation is called, I understand, a Dalek.
- Ben: It knew who you were. It sounds ridiculous, but it did.
- The Doctor: It knew who I was.
- Ben: The Dalek knows who you are.
- Lesterson: Now, look at it. I have merely given it electrical power, but it is capable of storing it. Moreover, it responds to orders. Turn around. [The Dalek obeys] Move that chair. [The Dalek pushes the chair across the room] Stop. [The Dalek stops] You see? Well, just think what this could do for our mining program, our processing, packaging. Dozens of labour jobs, Governor. It may even supply the end to all this Colony's problems.
- The Doctor: Yes, it will end the colony's problems, because it will end the colony!
- Dalek: I am your servant.
- Lesterson: It, it spoke! Janley, did you hear it? It can actually talk.
- The Doctor: It can do many things, Lesterson. But the thing it does most efficiently is exterminate human beings. It destroys them, without mercy, without conscience. It destroys them. Utterly. Completely. It destroys them.
- Dalek: [Trying to drown out The Doctor] I am your servant. I am your servant. I am your servant. I am your servant. I am your servant.
- The Doctor: [Talking about the Daleks] I know the misery they cause. The destruction.
- The Doctor: Yes. When I say run, run like a rabbit. Run!
- (17 December 1966 - 7 January 1967)
- [The Doctor is pretending to be a German doctor.]
- The Doctor: You suffer from headaches?
- Perkins: No, I don't.
- [The Doctor bangs his head on the table.]
- The Doctor: Oh, dear. No headaches?
- Perkins: Well... that...
- [The Doctor bangs his head on the table again.]
- The Doctor: Oh, dear. You call me a liar?
- (14 January 1967 - 4 February 1967)
- The Doctor: Just one small question: Why do you want to blow up the world?
- Zaroff: Why? You, a scientist, ask me why? The achievement, my dear Doctor. The destruction of the world. The scientist's dream of supreme power!
- The Doctor: Amazing. The professor leads the field in scientific discoveries. What a fantastic conception, to control the world from a test tube.
- Damon: That's right.
- The Doctor: Well, two can play at that game. Have you ever seen this? (The Doctor picks up two test tubes and pours one into the other, which releases a gas enabling the Doctor to escape.)
- Zaroff: NOTHING IN THE WORLD CAN STOP ME NOW!
- The Doctor: Zaroff, I think you ought to know the sea has broken through and is about to overwhelm us here.
- Zaroff: Don't listen to him. The man lies.
- The Doctor: Then perhaps the distant roaring that we can hear is just the goddess Amdo with indigestion.
- (11 February - 4 March 1967)
- The Doctor: This unit automatically controls the pulse, the temperature and the breathing.
- Polly: A sort of electronic doctor.
- The Doctor: Yes. Almost got striped trousers!
- [A delirious Jamie spots a Cyberman.]
- Jamie: It's you! The Phantom Piper!
- The Doctor: There are some corners of the universe which have bred the most terrible things. Things which act against everything we believe in. They must be fought.
- The Doctor: I simply don't understand it.
- Polly: Doctor, it wouldn't, I mean it couldn't possibly have anything to do with Lister, could it?
- The Doctor: Lister?
- Polly: Well, I mean, you did say that you took your degree in Glasgow in 1888. It does seem an awful long time from now, 2070 or whatever it is.
- The Doctor: Polly, are you suggesting that I'm not competent to carry out these tests?
- Polly: Oh, no. No, no, no, no. I was just wondering if there was anything that Joseph Lister didn't know in 1888 that might possibly help you now.
- The Doctor: Shh! Somebody's coming. It's Mister Hobson, out for blood. Ours. Look busy. Quick!
- Hobson: Well Doctor, as I was saying, you've had your chance and you've come up with absolutely nothing. Now, I-
- [The technician cries in pain and drops to the floor]
- The Doctor: Now don't touch him! Let me look...
- [The Doctor moves the technician and reveals his hand is covered in black lines]
- Hobson: Charlie, and what's your name.. Ben, give us a hand to get him into the medical unit!
- The Doctor: Try not to touch his skin.
- [They both pick him up, and rush him to the medical unit. Hobson, Polly and The Doctor sit back down again. Then, The Doctor looks at the sugar container, with a look of realisation, then proceeds to knock the cup out of Hobson's hand just as he is about to drink the coffee.]
- The Doctor: DON'T DRINK THAT! It's the sugar! Don't you see, that's why the disease doesn't affect everyone, it's the sugar! Not everyone takes it! Now don't touch it!...
- [Polly and Hobson look at each other confused, as The Doctor picks up the sugar carefully with a piece of equipment and brings it to the lab.]
- Hobson: What are you doing?
- The Doctor: Just be patient.
- [The Doctor examines the sugar under a microscope, revealing the disease hidden inside]
- The Doctor: Just as I thought. A large, neurotropic virus.
- Hobson: Like the space plague?
- The Doctor: No. A large, infective agent that only attacks the nerves. That's why the patients have these lines on their faces and their hands. It follows the course of the nerves under the skin.
- Hobson: That's all very well, but how did it get in here?
- The Doctor: Oh, it is the Cybermen. I believe they have deliberately infected the base.
- Hobson: My men have searched every square inch of the base, there's no space to hide a cat, let alone a Cyberman! Anyhow, how did they get in?!
- [Everything goes quiet for a second]
- The Doctor: One moment...
- [The Doctor and co walk over to the medical room]
- The Doctor: You say you searched all the base?
- Hobson: Yes. What of it?
- The Doctor: Every nook and cranny?
- Hobson: Yes.
- The Doctor: No chance of anyone hiding anywhere?
- Hobson: None whatever.
- The Doctor: Did your men search in here?
- Hobson: Well...
- The Doctor: Did they?
- Hobson: Well...
- [sighs]
- Hobson: There are always people in here so they thought that...
- The Doctor: [whispering urgently] Did they search in here?
- Hobson: No!
- Polly: But there's nowhere in here they could hide.
- [the Doctor inspects all the beds in turn until he comes to one particular bed, where he sees the boots of a Cyberman sticking out]
- Polly: Oh no! No! No! Oh no!
[The Cyberman rips off the cover, and pulls out a Cybergun]
- The Doctor: There we are! In perfect flight!
- Polly: Oh, and look what happened last time!
'
- The Doctor: Oh, and all that a lot of fuss, it was just a bumpy landing, that's all, it won't happen again!
- The Doctor: I know...
- Ben: What are you up to now?
- The Doctor: Let's have a look at the time scanner.
- Polly: The what?
- The Doctor: The time scanner! Instead of showing us a normal picture of where we are, it, gives us a glimpse of the future.
- Jamie: A second sight? Very dangerous...
- The Doctor: Oh, nonsense! I, haven't used it much, it's, not very reliable as you can see..
- Polly: Doctor... LOOK!
[A Macra claw appears]
- (11 March - 1 April 1967)
- Controller: [protesting against something] I... I will tell them. I will tell them. I... I'll do what you say. K-keep away. Don't touch me! I-I'll obey!
- [a claw is seen on screen dragging the old man off]
- Jamie: What's that? What's happening!
- Polly: Doctor, that was it? that thing in the picture! That was the claw! They're in control.
- Pilot: Take them out of here. They are condemned to the pits!
- Polly: Macra!
- Pilot: Take them away!
- Polly: They're in control!!!
- Polly: The old shaft. Doctor, that's where Jamie is!
- The Doctor: So they're going to pour this gas in the old shaft - gas they value above all else. What do you make of that, Polly?
- Polly: For goodness sake, Doctor. What are you going on about?
- The Doctor: Don't you see? Control are not pouring this poisonous gas into the old shaft to kill Jamie. They've quite another reason.
- Polly: Doctor, you've got to do something to help him.
- The Doctor: Before we act, we must think. Now, the Macra that have come to the surface of this planet have not found sufficient gas in the atmosphere, so they've had to get somebody to pump it up from down below.
- Polly: But, if it's life and death to them, why do they waste it? Why divert it into the old shaft?
- The Doctor: [thinking aloud] That's obvious, Polly, obvious. Because there's something trapped down there they wish to keep alive!
- Pilot: I really don't know why I trust you, Doctor.
- The Doctor: Oh, perhaps I've got an honest face.
- (8 April - 13 May 1967)
- Jamie: [seeing an aeroplane at Gatwick Airport]: Ooh, it's a flyin' beastie!
- Commandant: [incredulously] The pilot said what?
- Meadows: [desperately] A police box on the runway.
- Commandant: A likely story. Tell him to get back in the stack and await further instructions.
- Meadows: Yes, Sir.
- The Doctor: [happy to see Polly] Commandant, this is the girl I was telling you about.
- Polly Double: [Polly gives him a puzzled look] I beg your pardon?
- Commandant: Do you know these gentlemen?
- Polly Double: No. Why? Should I?
- Commandant: According to them, they know you.
- The Doctor: Now where have you been, Polly?
- Polly Double: Polly? My name isn't Polly. You must have made a mistake. I've never seen them before in my life!
- Jamie: What's a passport?
- The Doctor: Some sort of official mambo jambo.
- The Doctor: Well, in view of the facts that I’ve already presented - the ray gun, this pen and one or two other things - I think we’re dealing with people who are not from this planet.
- The Doctor: When did you learn such excellent English?
- Polly Double: [Annoyed] ... I had an English governess.
- (20 May - 1 July 1967)
- The Doctor: I am not a student of human nature. I am a professor of a far wider academy of which human nature is merely a part.
- The Emperor Dalek: The experiment is over?
- Doctor: Yes. I have implanted the human factor in the three Daleks that you gave me.
- [to Waterfield and Jamie]
- Doctor: When I say "run", - run!
- The Emperor Dalek: Speak louder!
- Doctor: I was merely telling my friend that the day of the Daleks is coming to an end.
- The Emperor Dalek: Explain.
- Doctor: It's very simple. Somewhere in the Dalek race there are three Daleks with the "Human Factor". Gradually, they will come to question. They will persuade other Daleks to question. You will have a rebellion on your planet!
- The Emperor Dalek: No!
- Doctor: I say, yes! I've beaten you, and I don't care what you do to me now!
- The Emperor Dalek: Silence. The "Human Factor" showed us what the "Dalek Factor" was.
- Doctor: [his "triumphant" face falling] What?
- Jamie McCrimmon: Well, what does that mean?
- The Emperor Dalek: Without knowing, you have shown the Daleks what their own strength is.
- Edward Waterfield: While you were doing one thing, they were really making you do another.
- The Emperor Dalek: The "Human Factor" is useless.
- Doctor: You still have those three Daleks to contend with.
- The Emperor Dalek: They will be impregnated with the "Dalek Factor". Your discovery, but your work is not over.
- Doctor: I won't work for you!
- The Emperor Dalek: You will obey!
- Jamie McCrimmon: What is the "Dalek Factor"?
- Doctor: You want me to guess? It means to obey, to fight, to destroy, to exterminate. I won't do it.
- The Emperor Dalek: Watch!
- [a light comes on, revealing the TARDIS]
- Jamie McCrimmon: The TARDIS, Doctor!
- The Emperor Dalek: You will take the "Dalek Factor". You will spread it to the entire history of Earth!
- Jamie: [to The Doctor] Anyone would think that it's a little game, and it's not. People have died. The Daleks are all over, fit to murder the lot of us, and all you can say is that you've had a good night's work. Well, I'm telling you this, we're finished. You're just too callous for me. Anything goes by the board, anything at all. You don't give that much for a living soul except yourself. Just whose side are you on?