[Research complex]

(The Doctor is driving along and singing an aria from La Traviata, but he doesn't know the words - except its title.) 
DOCTOR: Ra, ra, rum, rum, da, ra! Ra, ra, da, dum, da ,dah. La Donna e mobile, ra, ra, ra, rum, da, dah. De, dah, da, rum, da, dah, bah ,de, da, dum, da, dah. Da, da, dah, rum, bum.
(He waves at security as he drives into a Restricted Area. Welcome to Hoo, on the Isle of Grain. A man with a moustache, dressed in white overalls is whistling as he pedals his bike. He stops, gets off and takes a toolbox, then walks down a few steps where he meets a man in a white lab coat.)
SLOCUM: Hello, John. how's it going on in there?
BROMLEY: Oh, still drilling away like mad.
SLOCUM: Sound's more like a blooming dentist!
BROMLEY: Yes.

[Central Control]

(Plenty of computer panels and white-coated people with clip-boards.)
SLOCUM: Excuse me, Sir Keith?
GOLD: Yes?
SLOCUM: You called for someone from maintenance.
GOLD: Ah yes. I'd like you to have a look a number two output pipe.
SLOCUM: Oh, on the blink again, is she?
GOLD: Yes, I've had it take out of service. We've switched over to one and three.
SLOCUM: Okay, let's take a look at it.
(They walk down a short passageway.)

[Drill head]

(A noisy room with more clip-board carriers and a circular well in the middle. This has one large pipe in the middle and several smaller ones attached around the side.)
SLOCUM: I see what you mean. Okay, I'll fix it up.
GOLD: As quickly as possible, please. Professor Stahlman doesn't want any delays.
SLOCUM: Don't worry about it. It doesn't look too serious.
GOLD: Good. Thank you.

[Central Control]

(Gold returns. An imperious looking man with a neat beard enters, with his lady assistant staying one step behind.)
STAHLMAN: Sir Keith? Why has the drilling rate been slowed down?
GOLD: Oh, number two pipe is out of action. Naturally, we had to decelerate.
STAHLMAN: Oh, I do understand the technical problems.
GOLD: I didn't mean to imply otherwise.
STAHLMAN: What I don't understand is why you took it upon yourself to interfere.
GOLD: Well, I saw the malfunction report on number two pipe several days ago. I saw no report of its repair. I assumed you must have overlooked it.
STAHLMAN: I overlook nothing, Sir Keith. The malfunction on number two pipe's not sufficient to warrant a stoppage in the drilling and you have no authority to order one.
GOLD: Professor Stahlman, as Executive Director of this project, my concern
STAHLMAN: Your concern is with such important matters as the canteen facilities and the new roster for the cleaners. Anything to do with the drilling is my concern and mine alone. And that includes minor maintenance problems.
GOLD: Surely in a situation like this, there's no such thing as a minor problem?
STAHLMAN: Sir Keith, I'll make a bargain with you. You stay away from my drilling and I'll let you run your canteen.
(Stahlman leaves, but his assistant, Petra Williams, remains. At the drill head, Slocum loosens some bolts attaching the drill with a wrench. He sits back on his heels when green ooze comes out. He touches it and pulls his hand away in pain. His skin has turned green.)
GOLD: Bit why is he so unreasonable? You'd think I'm some sort of a rival.
PETRA: He's been working on this project all his life. Naturally, he feels possessive about it.
GOLD: Well, I've got another piece of news he won't altogether care for.
PETRA: What's that?
GOLD: I've sent for a drilling consultant. A chap called Greg Sutton. One of the most experienced oil men in the world.
PETRA: But this isn't an oil rig. We use a totally different method of drilling.
GOLD: Yes, yes, I know, but I'd feel happier if someone on this project knew a little more about the purely practical aspects of drilling and its dangers.
PETRA: When does he arrive?
GOLD: Oh, any time now. He's flying in from Kuwait.
(Slocum enters, slowly.)
STAHLMAN: Oh, have you finished?
SLOCUM: Yes.
(Slocum leaves.)
STAHLMAN: Good. Put number two pipe back into service and accelerate drilling speed three and a half percent.
MAN: Yes.
STAHLMAN: Perhaps we can now make up for lost time.
(Slocum leaves the underground complex and staggers past where he left his bike towards the rail tracks. He leans against a metal ladder. A man in a brick building spots him and runs over to help. Slocum attacks him viciously.)

[Brigadier's office]

(Sergeant Benton hammers a nail into a wall and hangs a group picture on it. The Brigadier enters from the Control room through a nine inch thick door.)
BRIGADIER: Morning, Benton.
BENTON: Morning, sir. It's the best they could do us on such short notice.
BRIGADIER: It'll do. Have you contacted the Doctor?
BENTON: He's on his way over, sir.
BRIGADIER: Anything on Slocum?
BENTON: No, sir. The lads are still looking.
BRIGADIER: Still?
BENTON: It's a rambling place this, sir. Slocum knows it a lot better than we do. If we had more men, we could
BRIGADIER: No, we don't want a panic.
(The Doctor enters.)
DOCTOR: Hello, Brigadier. Making yourself at home?
BRIGADIER: How are you, Doctor?
DOCTOR: Fine, thank you, fine.
(The Doctor picks up a framed photograph from the pile on the Brigadier's desk.)
DOCTOR: Good heavens. Which one's you?
BRIGADIER: Well, don't you recognise one?
DOCTOR: No, no, no, don't tell me. let me guess.
(The officers in the picture are all wearing shorts, so it was taken somewhere tropical.)
DOCTOR: Not that one. Not that one. What, none of them?
BRIGADIER: Fifth from the left, third row.
DOCTOR: (laughing) Yes, well, if it's true, I can see why you grew that moustache.
BRIGADIER: Trouble seems to follow you, doesn't it, Doctor?
DOCTOR: What do you mean?
BRIGADIER: You persuade me to allow you and Miss Shaw to attend this project as observers
DOCTOR: Allow? Look, Miss Shaw may have the misfortune to work for you, Brigadier. I am a free agent.
BRIGADIER: And within a few hours of your arrival, I have a motiveless murder on my hands.
DOCTOR: What?
BRIGADIER: Late yesterday afternoon, one of the technicians was beaten to death with this.
(Slocum's wrench.)
DOCTOR: And do you know who did the killing?
BRIGADIER: The wrench was found near the body. It belongs to a drill-head rigger called Harry Slocum. We're still looking for him.
DOCTOR: Do you know anything about him?
BENTON: Seems to have been one of the most popular men on the complex, sir.
BRIGADIER: Something else, Doctor. Try touching the wrench.
DOCTOR: Oh, it's still warm.
BRIGADIER: When it was first found, it was red hot, as though it had been in a furnace. Any theories?
DOCTOR: If the wrench had been subjected to intense energy, it might have disturbed its atomic make-up.
BRIGADIER: Chase up those patrols, will you, Benton? I want that man Slocum found.
BENTON: Right away, sir.
(Benton leaves.)
BRIGADIER: Doctor, why were you so keen to observe this project?
DOCTOR: Well, it's a matter of great scientific interest, my dear fellow. First penetration of the Earth's crust. Well, naturally I'm interested.
BRIGADIER: Yes, of course.
DOCTOR: Yes, well, I'd concentrate on finding that rigger if I was you. Well, excuse me, I must get back to work.
BRIGADIER: You're taking part in the project?
DOCTOR: Yes, in a way. Some related experiments, you know.

[Drill head]

SUTTON: Getting a respectable tan, bingo! I get snatched off a drill rig in Kuwait just when I'm sure we've made a strike, flown back so fast my stomach's still over the Med and I still haven't the faintest idea what I'm supposed to be doing here.
GOLD: Well, I asked for a top oil rig man, Mister Sutton, and you're the one they sent me.
SUTTON: Well, that's very flattering. Now look, this is a government project, right?
GOLD: Right.
SUTTON: So now I'm a sort of temporary civil servant?
GOLD: Broadly speaking, yes. How do you like the idea?
SUTTON: No comment. What's this supposed to be?
GOLD: That, Mister Sutton, is the drill head.
SUTTON: That is a drill head? You've got to be joking!
GOLD: No, that's a drill head, I assure you. The only one of its kind in the world.
SUTTON: Well, how deep are you?
GOLD: Twenty miles.
SUTTON: Twenty miles? Oh, come on now. You'd get such a whip in the drill pipes, they'd fracture.
GOLD: No pipes, Mister Sutton. A robot drill with its built-in power source, fed by cables from our own nuclear reactor.
SUTTON: Twenty miles. Well, you're liable to wake up Old Nick going that deep.
GOLD: Yes! As a matter of fact, some of the technicians have nicknamed this place the Inferno. Come around here. There's the monitoring system over there, you see? Then over here we have the alarm circuitry.
SUTTON: What's it all in aid of?
GOLD: Well, soon we shall penetrate the Earth's crust and then we'll be able to tap the pockets of Stahlman's gas that lie beneath it.
SUTTON: Pockets of what?
GOLD: Stahlman's gas. So named in honour of the originator of the project.
SUTTON: You mean like North Sea gas?
GOLD: No, no, no, no. An infinitely more powerful energy source.
SUTTON: What do you do with it once you've got it?
GOLD: Well, according to Professor Stahlman, we shall have, quote, a vast new storehouse of energy which has lain dormant since the beginning of time, unquote.
SUTTON: You learn something new every day. Now what did you say these pipes do?
GOLD: They siphon the coolant chemical down to the bore.
SUTTON: Okay, Sir Keith. Well, I get the picture, but I still don't see where I fit in.
GOLD: Well, I want someone on this project who's got a good practical knowledge of drilling, and of coping with any emergencies that may arise.
SUTTON: Are you having trouble here then?
GOLD: Not yet.
SUTTON: But you may have?
GOLD: Well, it's my job to cover any eventuality, Mister Sutton. Now it's time I introduced you to some of the senior staff.

[Central Control]

(A counter is clicking down from 59:28:47.)
GOLD: Petra, this is Mister Sutton, the oil man I told you about. This is Miss Petra Williams, who's been personal assistant to the Professor for some years now.
SUTTON: Hi.
PETRA: How do you do?
SUTTON: All the better for seeing you, Petra. Perhaps you could help me settle in the place?
PETRA: How do you mean, Mister Sutton?
SUTTON: Well, you know, show me round, dash off a few letters. Perhaps I could borrow you for a bit.
PETRA: Mister Sutton, I am Professor Stahlman's personal assistant, not a typist, and I'm not available for borrowing. Will you excuse me?
(Petra leaves.)
SUTTON: I'd say I'd been snubbed, wouldn't you?
GOLD: Come and meet the boss.
STAHLMAN: Just take them (unintelligible)
WOMAN: Yes, sir.
GOLD: May I present Professor Eric Stahlman, the instigator of the entire project.
STAHLMAN: The instigator? You make it sound as if I'd perpetrated some crime against humanity.
GOLD: Hardly that, Professor. This is Mister Sutton.
STAHLMAN: So I gather. Another recruit to your cause, no doubt.
SUTTON: What cause?
STAHLMAN: Well, his crusade to bring this whole operation to a grinding halt, Mister Sutton.
GOLD: Professor, please.
STAHLMAN: Well, he's a dedicated man, you see, dedicated to stifling us with over-caution and an over-abundance of experts and advisors. We're drowning in them, Mister Sutton.
SUTTON: I didn't volunteer for this job, you know.
STAHLMAN: How you came here is of no importance to me. You're here. We see them everywhere. Advisors on this, advisors on that.
(The Doctor enters.)
STAHLMAN: Look, there's another one.
DOCTOR: Our liver playing us up again this morning, is it Professor?
SUTTON: You have problems, Sir Keith.
GOLD: Yes.
SUTTON: Who's the gentleman in the fancy dress?
GOLD: Ah, that's the Doctor. A brilliant mind. We're very lucky to have him as advisor. Come, I'll introduce you. Doctor, may I introduce Mister Sutton.
SUTTON: Hello, Doc.
DOCTOR: Welcome to the Inferno, Mister Sutton.
SUTTON: And what do you think of this project, Doc?
DOCTOR: Well, I think that certain people ought to pay a lot more attention to the warnings of this computer.
SUTTON: Like him, you mean?
DOCTOR: Yes. Mind you, I'm not wild about computers myself, but they are a tool. If you have a tool, it's stupid not to use it.
(The Doctor goes to a side panel and flips a switch.)
DOCTOR: Power for my own little project. Nice to have met you, Mister Sutton.
(The Doctor starts to leave.)
STAHLMAN: All those so-called experts. It's a waste of valuable time and money.
(The Doctor goes to a technician making notes at a computer terminal.)
DOCTOR: Give that more lateral compensation, old chap, or you'll blow the main condenser banks. Cost thousands to put that right. Waste of valuable time and money. Hmm? (The Doctor leaves and Stahlman goes over to the terminal to check.)
STAHLMAN: I'm rapidly losing patience with that man.

[Outside the Doctor's workshop]

(The Doctor drives over to a hut guarded by a UNIT soldier.)
LATIMER: Morning, sir.
DOCTOR: Good morning. Any sign of Slocum yet?
LATIMER: No, we're still searching for him.
DOCTOR: Nasty business that.
LATIMER: Yes. Still, you should be safe in there. I'm sure this Harry Slocum character won't have one of your funny gadgets.
DOCTOR: Funny gadgets?
(The Doctor takes out his sonic screwdriver and activates it. The workshop doors open.)
DOCTOR: It's only a door handle.

Doctor's workshop]

(The Doctor drives Bessie inside then closes the doors. He appears to be well established here, with full bookshelves. Liz is working. The Tardis console is in the middle of the floor.)
DOCTOR: Any progress?
LIZ: I've isolated one of the faults.
DOCTOR: Good.
LIZ: Oh, did you get those figures from the computer?
DOCTOR: Yes, but I think you'll find they only confirm what we already know.
LIZ: Well, I'll check them again anyway. How are things at Central Control?
DOCTOR: Oh, the usual friction between Sir Keith and Stahlman.
LIZ: Oh, did you see the Brigadier?
DOCTOR: There's been a murder, Liz.
LIZ: I know. One of the sentries was in earlier making a spot check. He told me about it.
DOCTOR: It's a dreadful business, a murder without a motive. Right, let's get back to work, shall we?
LIZ: Doctor, you're not still thinking of making a run with the Tardis console, are you?
DOCTOR: Indeed I am. That's why we came here.
LIZ: Now be sensible. It's too dangerous.
DOCTOR: Look, Liz. Look, without the Tardis I feel rather lost. A stranger in a foreign land. A shipwrecked mariner.
LIZ: When do you want to make this trial run?
DOCTOR: In a minute.
LIZ: Hey, you're not serious? Why the sudden rush?
DOCTOR: Right, we've been over this many times. You know exactly what to do, don't you?
LIZ: Yes.
DOCTOR: Well then, take up your position and I'll switch the nuclear power through.
LIZ: I wish you'd think again.
DOCTOR: Liz! Please.
(Liz throws some switches then stands by the power breaker.)
DOCTOR: All right?
LIZ: Right.
DOCTOR: Now, at my signal, give me first stage power and then full boost a fraction later.
LIZ: Supposing it doesn't work?
DOCTOR: I'll think of something. I hope.

[Nuclear Reactor Switch Room]

(Somewhere else in the complex, Slocum has now got green skin, hairy hands and a tendency to snarl. He enters the Nuclear Reactor Switch Room building. A technician is on the telephone.)
BROMLEY: Yes, yes, that's right. All readings normal, no peaks at all. Yeah. Look, I've done a complete routine check.
(Slocum sneaks in.)
BROMLEY: No, everything's very quiet up here.

Doctor's workshop]

DOCTOR: Right. Stand by, Liz.
LIZ: Standing by, Doctor.
DOCTOR: Switch to first stage power. Full boost, Liz.
(7 Megga volts. Sic. 8 would be in the red. Meanwhile, the green Slocum has blood on his overall. He puts his hands to his head in pain then goes to a lever and pulls it all the way down to the red section. The Tardis console starts shaking.)
DOCTOR: Too much power, Liz! Too much power.
LIZ: I can't cut back! The circuits are locked and overloading!
(The Tardis console and the Doctor dematerialise. They fly through a distorting nothingness and get separated. Finally Liz pulls down one of the power breakers and the voltage drops back to 7M. The Doctor continues to be pulled at by strange forces. Liz uses a piece of wood on the other handle to get more leverage, and the voltage drops to nil. The console materialises first, then the Doctor lands on the floor, with his feet on the console. Liz switches everything off and goes to him.)
LIZ: Doctor, are you all right?
DOCTOR: Yes. I still feel dizzy. I seem to be in one piece anyway.
LIZ: What happened? Where did you go?
DOCTOR: I'm not sure. I seemed to be in some sort of limbo. There was a barrier I couldn't break through. We must make another trial run.
LIZ: After all that?
DOCTOR: Because of all that. I wonder where I was exactly? Where I was going?
LIZ: Wherever you were, you very nearly didn't get back.
DOCTOR: Well, next time we must ensure that I do.
(A klaxon sounds.)
LIZ: The drill head!

[Central Control]

(Smoke is pouring out of the drill head as the blast door comes down.)
PETRA: (into phone.) We must get through to the main switch room. This is an emergency.
STAHLMAN: Sir Keith! Did you order those shield to be lowered?
GOLD: Yes, I did.
STAHLMAN: Why?
GOLD: Well, this is a Red One emergency, Professor.
STAHLMAN: Is it? I haven't said so yet.
GOLD: Surely it's quite obvious?
STAHLMAN: Get those shields back up again now.
GOLD: Professor Stahlman
STAHLMAN: Anything that happens in this area is my responsibility.
GOLD: Well, at least order the power to be shut off.
STAHLMAN: What, and stop the drill? Petra, have you contacted the reactor yet?
PETRA: I still can't get an answer, Professor.
STAHLMAN: Well, you must get an answer.
SUTTON: At that depth and that pressure, you'd never get it going again. The drill bit would seize up immediately. You'd have to abandon the bore.
GOLD: That mightn't be a bad idea.
STAHLMAN: (into phone) Well, try them again and keep on trying until you get 'em. Petra, see if they have the coolant flowing yet.
SUTTON: Hey, wait a minute. I wouldn't go in there if I was you.
PETRA: Will you let go of my arm?
SUTTON: The pressure in there could blow the roof right off this building!
PETRA: Thank you, I know what can happen, but I have a job to do. Now just don't interfere!
(Petra leaves.)
SUTTON: Are you some kind of idiot?
GOLD: Ah, Doctor, can you make any sense of this data?
BRIGADIER: What's happened, Doctor?
DOCTOR: There's been a nuclear power surge. Actually, we experienced it ourselves earlier. It must have gone quite mad at the reactor.
BRIGADIER: There's been another murder. One of my soldiers.
DOCTOR: Where was the body found?
BRIGADIER: On the waste ground.
DOCTOR: Anywhere near the reactor?
BRIGADIER: Not all that far from it.
DOCTOR: Professor? We think we know what's wrong.
STAHLMAN: Doctor, stop wasting my time, will you?
DOCTOR: Well, I'm afraid I was wrong, Professor.
STAHLMAN: What?
DOCTOR: It's not so much your liver as your general disposition. Brigadier, come on.
(Petra runs in from the drill head as the Doctor and Brigadier leave.)
PETRA: Professor Stahlman.
STAHLMAN: What's happening in there?
PETRA: The coolant controls are jammed with the heat.
SUTTON: I wouldn't go back in there.
PETRA: Rather nervous for an oil man aren't you, Mister Sutton?
SUTTON: I'm not nervous, darling, I'm terrified! I know what can happen in there.
PETRA: And I don't?
SUTTON: I doubt it. And you're not brave, you're just plain stupid.
PETRA: Professor Stahlman knows what's happening. He can deal with it.
SUTTON: Do you want to bet?

[Drill head]

(Stahlman and a technician are straining at a valve wheel when Petra and Sutton enter.)
SUTTON: It's okay, Professor. Let me have a go at that. Hold tight, everyone. We'll soon have it under control.

[Nuclear Reactor Switch Room]

(The Doctor and Brigadier run in, with Benton following.)
DOCTOR: Look.
(They kneel to check Bromley, and Green Slocum burst in through another door.)

Episode Two

[Nuclear Reactor Switch Room]

(The Doctor stops Benton.)
DOCTOR: No, don't move. It'll only antagonise him.

[Drill head]

SUTTON: Okay, don't worry. She'll calm down now the coolant's flowing.
STAHLMAN: Thank you, Mister Sutton.

[Central Control]

(Petra is at a control panel.)
STAHLMAN: Still too much power from the nuclear reactor.
PETRA: I think the Doctor went to deal with it.
STAHLMAN: What? Well, check it please, Petra.

[Nuclear Reactor Switch Room]

DOCTOR: Look, there's nothing to be frightened of, old chap.
(A phone rings. Slocum looks around Wyatt dodges behind an equipment rack, rifle ready.)

[Central Control]

STAHLMAN: Well?
PETRA: There's still no reply from the main switch room.
STAHLMAN: What do those fools think they're doing? Hello? Hello?
(In the Switch Room, Wyatt signals his intention to Benton and the Doctor notices it. Slocum spots him coming round the equipment rack and charges. Wyatt shoots, but Slocum wrestles the rifle off him and throws him to the floor before finally collapsing himself.)
GOLD: It's still not a Red One emergency.
STAHLMAN: I know.
GOLD: Shall I give the order?
STAHLMAN: Not until I consider it necessary. Why does nobody answer this phone?

[Nuclear Reactor Switch Room]

(The soldiers drag Bromley away. The Brigadier stands behind the Doctor, ready to defend him should the still conscious Slocum attack again. The Doctor reaches for the power lever, but it is red hot.)
DOCTOR: Pistol. Pistol!
(The Doctor uses the butt of the Brigadier's pistol to push the lever back up to zero. Slocum slumps sideways by the wall.)
DOCTOR: No, no. Don't touch him. Look at that wall. It's scorched.
(The Doctor answers the phone.)
DOCTOR: Hello? Oh, it's you, Stahlman. Thank you, we've dealt with the matter ourselves.

[Central Control]

(The drill head is cooling down.)
SUTTON: Well done, everyone. I'll have a new medal struck. The Order of the Turkish Bath.
STAHLMAN: The emergency has been contained. Return to your normal duties, everyone.
SUTTON: We contained it by the skin of our teeth. We may not be so lucky next time.
STAHLMAN: The main operation was not at fault. Those idiots at the nuclear reactor boosted the power too high.
SUTTON: All right, so it was some kind of accident. They happen, you know? You have to make allowances, take precautions.
STAHLMAN: I can make no allowances for incompetence, Mister Sutton.
(Stahlman leaves.)
SUTTON: Petra. Is that man a complete nut?
PETRA: I don't think so, Mister Sutton. Thank you for helping with the emergency.
SUTTON: Well, if you really want to show your gratitude, there are one or two things.
PETRA: Like what?
SUTTON: Like call me Greg, for instance. It's my name. All this mistering makes me nervous.
PETRA: And second?
SUTTON: I've got one or two ideas.
PETRA: What about?
SUTTON: Safety precautions at the drill head area. Now, Stahlman listens to you. If you could convince him I'm talking sense, we might get somewhere.

[Nuclear Reactor Switch Room]

DOCTOR: Both bullets right through the heart.
BRIGADIER: But he was alive and moving for several minutes.
DOCTOR: Abnormal resistance, abnormal strength. That's not all.
(Benton enters.)
BENTON: Excuse me, sir. The medics are on their way over.
DOCTOR: Look, they'd better not touch the body for a while. It's radiating a good deal of heat.
BENTON: Right, sir.
(Benton leaves.)
BRIGADIER: The man's dead, Doctor.
DOCTOR: Heat, Brigadier. Like the wrench that killed that technician. Like that switch over there.
BRIGADIER: What about these two?
(Bromley and Wyatt)
DOCTOR: There don't seem to be any major injuries.
BRIGADIER: Shock?
DOCTOR: Possibly. I don't know.
BRIGADIER: Wyatt? Private Wyatt?

[Storage tank]

(Two actors stand on metal catwalks at the highest point of the complex. Which one has vertigo?)
BRIGADIER: Doctor, I need some answers.
DOCTOR: Mmm?
BRIGADIER: What did happen to Slocum?
DOCTOR: Some sort of retrogression of the body cells, I think.
BRIGADIER: I don't understand.
DOCTOR: Neither do I. Not fully, not yet.
BRIGADIER: It looked as if he was turning into some sort of animal.
DOCTOR: Yes. The process was relatively slow and it wasn't completed.
BRIGADIER: I'll have the devil of a job keeping this quiet.
DOCTOR: Why wasn't the metamorphosis completed?
BRIGADIER: That noise he was making. I've never heard anything like that before.
DOCTOR: I have.
BRIGADIER: Where?
DOCTOR: Krakatoa, the Sundra Straits. During the volcanic eruption of 1883.
BRIGADIER: Doctor, are you telling me that there's some link between Slocum and the volcanic eruption in Krakatoa?
DOCTOR: There could be.
(Benton climbs up.)
BENTON: Sir, Wyatt and the technician, they've disappeared.
BRIGADIER: What?
BENTON: They cleared off before the medics could look at them.
BRIGADIER: Come on.
(Benton and the Brigadier leave. The Doctor spots a figure on another catwalk across the top of more tanks.)
DOCTOR: Wyatt?
(The figure runs.)
DOCTOR: Wait!
(The Doctor goes after the figure, making sure he always has one hand on a rail. Wyatt still has his rifle with him. Finally the Doctor catches up.)
DOCTOR: Now Wyatt, listen to me. You need help.
(Green Wyatt swings the butt of his rifle like a club, but is too fierce and his momentum carries him over the rail and he falls about 25 metres.)
DOCTOR: Don't touch him! Whatever you do, don't touch him! 
(The Doctor makes his way down to the ground, watched by green-faced Bromley.)

[Drill head]

STAHLMAN: According to my calculations, Petra, we can accelerate the drilling speed by twelve percent without any adverse effects.
PETRA: Professor Stahlman, will you
STAHLMAN: This will advance the time of penetration of the Earth's crust by nearly five hours.
PETRA: Professor Stahlman, could you please come to Central Control? Sir Keith wants you to look at something in there.
STAHLMAN: Well, what on Earth is it?
PETRA: Something.

[Central Control]

(A metal box sits on a trolley.)
SUTTON: Do you reckon he'll know what it is?
GOLD: Well, if he does, he's a darn sight cleverer than the rest of us.
(The Doctor enters, then Stahlman and Petra.)
DOCTOR: Hello? What have we got here?
STAHLMAN: What is it, Sir Keith.
GOLD: Open it, please.
(A technician wearing flame-proof gloves unfastens the box and removes a vial of green liquid.)
GOLD: Now, we've been getting traces of this stuff from number two output pipe for some time now. Recently it's started coming out in greater quantities.
STAHLMAN: Analysis report?
GOLD: None. So far the substance has defied analysis.
STAHLMAN: Ridiculous. If it exists, it can be analysed.
GOLD: The labs say they can't get near enough to the stuff to carry out a proper examination. It took them all their time to siphon some off into that heat resistant jar.
STAHLMAN: Then we shall just have to wait till it cools down a bit, won't we.
DOCTOR: Well, I doubt whether it will cool down.
STAHLMAN: And who the devil asked you?
DOCTOR: I was just venturing an opinion.
STAHLMAN: Based on what?
DOCTOR: Krakatoa, actually.
BRIGADIER: Professor, I have to speak to you and Sir Keith on a matter of great urgency.
STAHLMAN: Oh, not just at this moment, if you don't mind.
BRIGADIER: I must insist, sir. This is vital.
STAHLMAN: Well then, talk to our good friend, Sir Keith. He's got time for talking. I haven't.
BRIGADIER: Professor, in the last few hours, three men have died in this establishment. Died violently. I must talk to you in my office, now.
STAHLMAN: Oh, very well.
BRIGADIER: Sir Keith?
(The Brigadier, Stahlman and Gold leave.)
LIZ: I'll examine that stuff in the labs. What do you think?
DOCTOR: I wish I could hear it, Liz.
LIZ: Hear it?
DOCTOR: I wonder if it screeches?
LIZ: Doctor, I think you ought to come and look at the main computer.
DOCTOR: Why? Something interesting?
LIZ: Something downright frightening, if you ask me.

[Brigadier's office]

STAHLMAN: But surely, Brigadier, this matter comes under the jurisdiction of the medical section, or security? It's a personnel problem. It's got nothing whatsoever to do with the technical side of this operation.
BRIGADIER: Professor, three men have died.
STAHLMAN: I'm sorry for that. But it's none of my responsibility.
GOLD: How can you say that? These deaths concern all of us.
BRIGADIER: The Doctor believes there is some connection between the
STAHLMAN: That Doctor has no authority in this establishment. How many times do I have to repeat that?
GOLD: His calculations on initial stresses were invaluable to this project. Without them
STAHLMAN: I would have come to the same conclusion.
GOLD: He came to his answers in ten minutes. You had a team of mathematicians working on it for a month.
STAHLMAN: That's hardly the point, Sir Keith.
BRIGADIER: Gentlemen, please. I am still waiting for some decision on my particular problems.
STAHLMAN: Well, as you say, Brigadier, they are your problems. Please deal with them as you see fit.
(The Doctor enters.)
DOCTOR: A question.
GOLD: Yes?
DOCTOR: Isn't anybody going to pay any attention to that computer out there?
GOLD: That computer is over-sensitive. Its data is unreliable.
DOCTOR: You talk about the thing as though it was your maiden Aunt.
GOLD: My own calculations are more specific.
DOCTOR: Yes, well I'll tell you something that should be of vital interest to you, Professor.
GOLD: Well, what?
DOCTOR: That you, sir, are a nitwit!
PETRA: Professor! Come quickly!
STAHLMAN: That man ought to be locked up!

[Central Control]

(The green liquid is bubbling and steaming. The jar is under great pressure and cracks are forming.)
PETRA: I think the jar's going to shatter!
STAHLMAN: Stand back, everybody.
(Stahlman reaches for the jar.)
DOCTOR: No, Professor, don't.
(Stahlman takes firm hold of the jar with his left hand and places it back in its box.)
DOCTOR: Yes, well, I wouldn't have done that if I was you.
STAHLMAN: Have that deep frozen at once. Right, return to work everybody. The entertainment's over.
(Stahlman continues to wipe his hand with a handkerchief.)
BRIGADIER: Are you all right?
STAHLMAN: Yes, of course. The jar was hot. It's nothing.
BRIGADIER: Then perhaps we can continue our discussion.
STAHLMAN: I hardly think that's necessary. As far as I'm concerned, everything's been covered.
BRIGADIER: Thank you for your co-operation.
(The Brigadier leaves.)
GOLD: What about the computer?
STAHLMAN: Well, what about it?
GOLD: Well, you can't just ignore it.
STAHLMAN: I prefer to rely on my own judgement. I've been concerned with this operation for eleven years and I know more about the details surrounding it than any machine.
DOCTOR: I hope so, because its message is perfectly clear.
STAHLMAN: What message?
DOCTOR: Come and see for yourself. It warns that drilling should be stopped immediately. Well, look at it, man. Are you blind?
STAHLMAN: That computer, as I have said, is inaccurate.
DOCTOR: You please yourself, sir. I've done the best I can to convince you. I may as well get back to my own work.
STAHLMAN: You may find that rather difficult. We can't supply you with any more nuclear power.
DOCTOR: Oh? Why not? STAHLMAN: We need all the energy we can get. I propose to accelerate the drilling by twelve percent. Cut the power to the Doctor's hut. Not to be reconnected under any circumstances.
DOCTOR: That's an incredibly childish attitude to take.
STAHLMAN: If you will excuse me.
(Stahlman leaves.)
GOLD: I'm sorry, Doctor.
DOCTOR: So am I, Sir Keith.

[Drill head]

STAHLMAN: Petra, listen carefully. Start the acceleration in exactly twenty five minutes time. That will make the time of penetration zero exactly forty nine hours from now.
PETRA: Professor Stahlman, shouldn't you at least consider what they're saying.
STAHLMAN: If I'd listened to all the others, Petra, this project would never have begun. And if I listen to them now, it'll never be completed. Have all systems modified to this new programming.
PETRA: Yes, Professor.
(Petra leaves. The palm of Stahlman's hand is turning green.)

[Central Control]

PETRA: Mister Phillips? Professor Stahlman has decided to modify the drilling rate. Could you join us at the computer, please?
DOCTOR: Liz? Go and check the tri-gamma circuits on the console again, will you?
LIZ: What do you want me to do that for?
DOCTOR: Look, please, don't ask any questions. There's a good girl.
LIZ: All right.
(Liz leaves. The Doctor goes unnoticed to the power control panel and flicks his energy supply switch, then leaves. Stahlman enters, goes to the main control desk, opens a panel in the back and removes a small computer circuit.)

[Brigadier's office]

(Stahlman enters. He searches the Brigadier's desk and finds the swagger stick in a drawer. Putting the circuit on the desk, he raises the stick.)
DOCTOR: Professor! What are you doing with that micro-circuit?
STAHLMAN: You'd do well to mind your own business, Doctor.
DOCTOR: That computer is a threat to you, isn't it? It could prove you wrong. Now give me that micro-circuit.
(Stahlman raises the stick to hit the Doctor.)
DOCTOR: Ai tavich!
The Doctor jabs his thumb in the region of Stahlman's collar bone. Stahlman drops the stick.)
BRIGADIER: Doctor! What on earth do you think you're doing?
DOCTOR: Venusian karate. It's very effective. Hold it long enough and the subject remains permanently paralysed.
BRIGADIER: Then I suggest you let him go.
DOCTOR: Oh, very well.
(The Brigadier catches Stahlman.)
BRIGADIER: Will someone please explain what's going on here?
DOCTOR: Shall I tell him or will you?
STAHLMAN: Brigadier, have that man expelled from this establishment!
(Stahlman leaves.)
BRIGADIER: Well, Doctor? Will you please tell me what's going on here?
DOCTOR: Look, don't you start asking me questions. Just keep your eyes open and follow me.

[Central Control]

DOCTOR: Professor, there are some questions that we would like to ask you.
STAHLMAN: Brigadier, this man is trying to sabotage my project.
DOCTOR: Would you mind telling us what you have in your left hand pocket?
BRIGADIER: Professor?
STAHLMAN: Oh, very well. (waistcoat) Nothing. (notebook) Left hand. (keys) Right hand. Satisfied? Now get that man out of my sight!
(Stahlman leaves.)
DOCTOR: I tell you he had a micro-circuit in his pocket.
BRIGADIER: Well, it isn't there now, and after all, he is in charge.
DOCTOR: Yes. Well, I suppose I've got something better to do with my time anyway.
(The computer goes quiet.)
DOCTOR: You see, it's packing up already.
(The Doctor leaves, the Brigadier goes another way. Stahlman goes to the wall by the Brigadier's office where he dropped the micro-circuit, and steps on it.)

Doctor's workshop]

DOCTOR: Did you find any damage to the main circuits?
LIZ: Two of the by-pass wires were burnt out, but apart from that, everything seems all right.
DOCTOR: Did you replace them?
LIZ: Yes.
DOCTOR: Good, good.
LIZ: What was all that business at Central Control?
DOCTOR: Oh, just a little contretemps between myself and Stahlman. Nothing of any importance.
LIZ: Well, with the nuclear power cut off, we're just wasting our time, aren't we?
DOCTOR: Oh, I don't think so.
LIZ: At least you won't be able to make any trial runs.
DOCTOR: Liz, it wasn't the console that was to blame. It was that nuclear power surge.
LIZ: I'm afraid you'll never know for sure, Doctor.
DOCTOR: Yeah. Would you do me a favour?
LIZ: Yes?
DOCTOR: Nip down to the control centre, will you, and feed these figures into the spare bank of the computer. They're some epsilon coordinates.
LIZ: Epsilon coordinates? You usually work those out in your head?
DOCTOR: Yes, I know, but I'm a bit tired.
LIZ: Yes, all right. Doctor?
DOCTOR: Hmm? Oh, I'm so sorry.
(The Doctor uses his sonic screwdriver to open the doors.)
LIZ: Thank you.
(The Doctor starts setting controls on the Tardis console.)

[Central Control]

(Liz has been watched by Bromley on her way to Central Control.)
LIZ: What's happened to the computer?
BRIGADIER: It's broken down.
LIZ: Oh well, the Doctor'll just have to work out these calculations in his head after all.
BRIGADIER: The Doctor sent you?

LIZ: Yes, I've just come from the hut.
BRIGADIER: But he was here when the machine broke down.
LIZ: What?
BRIGADIER: Didn't he tell you?
LIZ: No.
BRIGADIER: Stahlman's demanding that I get rid of him. It looks as though he sent you on a wild goose chase.
LIZ: Just a minute.
(Liz goes to the power control panel and sees the red light flashing.)
LIZ: Brigadier, come on!
(The Tardis console is shaking hard.)

[Drill head]

STAHLMAN: Twenty four. Sixty eight.
(The lights dim.)
STAHLMAN: Someone's using extra power. That Doctor!
(Stahlman runs into the control room and turns off the switch.)

Doctor's workshop]

(Liz uses a sonic screwdriver to open the doors as the Doctor, Bessie and the Tardis console dematerialise.)
LIZ: Doctor!

Episode Three

Doctor's workshop]

(Liz goes to the power breakers.)
LIZ: Nothing.
BRIGADIER: Miss Shaw?
LIZ: Stahlman's cut off the power. Wherever the Doctor is, he's trapped.
BRIGADIER: I think you'd better tell me what's been going on.

[Central Control]

(The clock reads 49:18:33 and counting.)
BRIGADIER: Professor Stahlman?
STAHLMAN: No, not now, Brigadier.
BRIGADIER: I want you to reconnect the power to the Doctor's hut.
STAHLMAN: Don't be ridiculous, my dear man.
BRIGADIER: Professor Stahlman, the Doctor has disappeared.
STAHLMAN: Excellent! At last he's done what he was told.
LIZ: No, no, you don't understand, he was engaged in an experiment and you switched off the power at a critical moment. Now, you've got to restore it.
STAHLMAN: Well, I denied the man a power source when he was under my feet. I'm certainly not going to reconnect it now he's gone.
GOLD: Stahlman, do be reasonable.
STAHLMAN: I've been more than reasonable. Up till now, I've tolerated these crackpot experts and advisors and only offered a token objection. But now that we've accelerated the drilling programme, I won't be obstructed any further.
GOLD: You had no right to accelerate the programme without proper consultation with the Ministry.
STAHLMAN: I have every right, Sir Keith.
GOLD: Very well, I'm sorry, but I shall have to refer the matter to the Minister.
STAHLMAN: Please do. I can tell you exactly what he'll say. That this project is vital to our industrial future. The country needs the new power source and Stahlman is the only one who can give it to us!
LIZ: Please. We must have a nuclear power system reconnected at once.
STAHLMAN: The matter is closed, Miss Shaw. Under no circumstances will any power, of any sort, be reconnected to the Doctor's hut.
(Stahlman leaves.)
BRIGADIER: Well, we tried.
GOLD: What exactly has happened to the Doctor?
BRIGADIER: He's vanished.
LIZ: And we're afraid he's in some kind of danger.
GOLD: Yes, well, we're all likely to be in some kind of danger, Miss Shaw, unless we can persuade the Professor to slow down the drilling rate.
BRIGADIER: Will you really go to London, sir?
GOLD: Well, I have no alternative. Something must be done about that man.
LIZ: Do you think they'll listen to you?
GOLD: Well, I very much doubt it. Stahlman was right. They believe he's the only one who can succeed with this project. I'm just a figurehead.
LIZ: When will you go?
GOLD: As soon as I clear up my work here.
LIZ: Shouldn't you go at once, Sir Keith?
GOLD: My dear young lady, this project is at a crucial stage. If Stahlman can find the slightest excuse to accuse me of inefficiency, who will listen to me then? Now, if you'll excuse me.

[Drill head]

(Stahlman's left palm is bright green. Petra sees him putting on a white cotton glove.)
PETRA: Are you all right, Professor Stahlman?
STAHLMAN: Perfectly.
PETRA: Hadn't you better get a Doctor to see that hand?
STAHLMAN: I'm perfectly all right. I suggest we continue with our work, Petra.
PETRA: Very well, here are the latest acceleration reports.

[Central Control]

BRIGADIER: I tell you there's nothing more we can do. I'm sorry.
LIZ: You don't seem very worried.
BRIGADIER: Professor Stahlman seems determined to blow us all to kingdom come, the Doctor has vanished into thin air and I have a number of unsolved murders on my hands. I promise you, Miss Shaw, I'm worried.

Doctor's workshop]

(The Doctor wakes up on the floor. The objects on the shelving are neatly arranged in boxes, not their usual jumble, and Bessie is parked facing the door, not inwards. The Doctor puts on his black leather gloves and goes over to where the power junction box should be. Instead there is a cork notice board with a picture of a man and a slogan.)
DOCTOR: Unity is strength? Who's been messing about with my equipment?
(The Doctor points his sonic screwdriver at the doors but they do not open. He tries again then opens them manually.)

[Outside the Doctor's workshop]

(All is quiet. He then notices the signs on the door - Technical Stores and a triangular symbol made of three arrows, the largest one up, and two to each side. He drives Bessie out and shuts the doors, then someone shoots at him.)
DOCTOR: What the blazes do you think you're doing?
(The soldier shoots again. The Doctor gets into Bessie and drives away, swerving to avoid the gunfire. A second man joins the shooter.)
LATIMER 2: It's a saboteur. He was in the technical stores!
BENTON 2: Well, get after him!

[Research complex]

(The Doctor drives through the research complex as if he were at Brooklands.)
SOLDIER: Halt! Halt, I say! Halt.
(The Doctor drives through, scattering the soldiers. As he carries on, other soldiers take pot-shots at him. The Doctor stops by a pile of barrels, but a soldier appears and jumps onto Bessie. He drives off again, struggling with the soldier until he throws him off into a convenient pile of hay. Finally he stops by a row of timbered buildings.)
BENTON 2: In there.
(Benton and Latimer run into the building next to Bessie. A dustbin lid raises, and the Doctor makes his escape on foot up into the storage tank area. From high up he watches the soldiers search for him.)
LATIMER 2: Try round the other side! Why don't we go down the ladder?
BENTON 2: One of you lot come with me.
SOLDIER: Come on, come on, come on!
(There is a snarling noise behind the Doctor and he turns to see green Bromley. The Doctor picks up a CO2 fire extinguisher and uses it on him. Bromley collapses with the cold.)
BENTON 2: There he is!
(The Doctor climbs higher, to the top of the gas storage tank, only to meet green Wyatt.)
BENTON 2: When you see him, shoot!
(The soldiers on the ground see a figure by the railing around the tank, and one fires. The figure falls about 10 metres and the soldiers run over to it. Elsewhere, a brunette in a brown RSF uniform walks past the Doctor hiding round the corner of a building.)
DOCTOR: Liz? Liz, it's me. Don't you recognise me? What's happened to everyone round here? Have you all gone mad? What are you doing in that ridiculous get-up?
(The woman draws a pistol from a holster.)
SHAW: Put your hands up.
DOCTOR: All right, Liz, a joke's a joke.
SHAW: Get back.
(She blows a whistle to her lips and blows. Benton and Latimer come running.)
BENTON 2: Here.
SHAW: Take him away.
BENTON 2: Yes, Leader.
DOCTOR: Liz, this is ridiculous!

[Central Control]

(The Doctor is escorted to the Brigadier's office.)
STEWART [OC]: Come.

[Stewart's office]

DOCTOR: Brigadier, will you kindly tell me what on
(The man in the chair swivels round to fix the Doctor with his one good eye. The other is under an eye patch, and has a deep scar running through it from hairline to jaw.)
STEWART: Is this the man?
DOCTOR: What on Earth are you doing in that get-up?
BENTON 2: Keep quiet!
STEWART: You will find it unwise to be insolent. How did you get inside this establishment?
DOCTOR: I beg your pardon?
STEWART: How did you get in here?
DOCTOR: Look, your name is Lethbridge Stewart?
STEWART: Yes.
DOCTOR: Brigadier Lethbridge Stewart?
STEWART: Brigade Leader.
DOCTOR: All right, Brigade Leader. Have it your own way. And you are Elizabeth Shaw.
SHAW: How did you know my name?
STEWART: You've been spying on this establishment.
DOCTOR: What are you talking about?
STEWART: Your name!
DOCTOR: My name? You ask me my name after all the years that you and I. Well now, wait a minute. Yes, I think I'm beginning to see what's happened here. Might I suggest you just call me Doctor?
STEWART: Doctor. Doctor what?
DOCTOR: Smith. Doctor John Smith.
STEWART: Smith. Yes, of course. And where do you come from, Doctor Smith? 
DOCTOR: Yes, well, this is where we come to the difficult bit.
STEWART: Well?
DOCTOR: I come from a parallel space-time continuum.
SHAW: Obviously, he is trying to confuse us, Leader.
DOCTOR: Yes, well, let me put it this way. I've been transported from another world. One that is running almost parallel to this one.
SHAW: He's unbalanced.
STEWART: No, I see what he's trying to do. He's trying to make us believe that he's mad. But it won't work, my friend.
DOCTOR: Now, now look, wait. You are Elizabeth Shaw.
SHAW: I am Section Leader Elizabeth Shaw, yes.
DOCTOR: Not a scientist?
SHAW: No.
DOCTOR: Oh. This is fascinating. So many similarities, yet so many differences.
STEWART: Enough! Now, I want the truth.
DOCTOR: Tell me, how far down is the shaft that you are drilling?
SHAW: Leader, he is a spy.
DOCTOR: And Professor Stahlman? Is his liver still playing him up? And Sir Keith? How is Sir Keith? Yes, now there's a man who might understand.
STEWART: What do you know about Sir Keith?
DOCTOR: Only that he's the Executive Director of this project. Yes, I should very much like to see him.
STEWART: Would you indeed?
DOCTOR: Indeed, I would. Failing that, Professor Stahlman. He's an opinionated oaf, I know, but at least he's a scientist.
STEWART: Very well.
SHAW: Are you taking this man to see the Director?
STEWART: Why not? Whoever he is, he'll never leave here alive.

[Central Control]

DOCTOR: Wait a minute.
(The Doctor looks at the countdown clock.)
DOCTOR: Three hours twenty two minutes? You're a lot more advanced with the drilling here.
BENTON 2: Come on!
(All the technicians are in white suits, not coats. Stahlman is also sporting dark glasses and is clean shaven.)
STEWART: The intruder has been apprehended, Director.
STAHLMAN 2: So I see.
STEWART: I thought you might like to question him.
STAHLMAN 2: I don't think so, no. You know what to do with spies.
STEWART: He asked to speak to Sir Keith Gold.
STAHLMAN 2: Did he? And did you tell him that might be rather difficult?
DOCTOR: Difficult why?
STAHLMAN 2: Sir Keith Gold was killed in a motor accident twenty four hours ago. Rather unfortunate.
DOCTOR: Sir Keith dead?
STAHLMAN 2: He was on his way to the Ministry in London.
DOCTOR: Yes, to complain about you, no doubt.
STAHLMAN 2: Who is this man?
STEWART: We have not yet established his correct identity, Director. He gave an obviously false name.
STAHLMAN 2: Have you no idea where he came from?
STEWART: He spoke of having come from some other dimension.
STAHLMAN 2: I've no time to waste on maniacs, Brigade Leader.
STEWART: Quite so. My apologies.
DOCTOR: Excuse me, but what about this computer?
STAHLMAN 2: The computer?
DOCTOR: Yes, it doesn't seem to be working.
STEWART: It's been sabotaged.
DOCTOR: Yeah, missing micro-circuit, do you think, Professor?
STAHLMAN 2: Obviously this man is responsible for the damage. Take him away.
STEWART: Benton!
(Benton uses his rifle to steer the Doctor back to the office.)
STAHLMAN 2: Carry on, Doctor Williams.
WILLIAMS: (Petra) Yes, Director.
(Stahlman leaves.)
GREG: (Sutton in suit and tie) Will you tell the Director that we have no pressure in the coolant pipes, please.
WILLIAMS: He's aware of that fact. He's had the pressure temporarily by-passed to the shaft himself.
GREG: Well, if an emergency develops, there'll be no safeguard at the drill head.
WILLIAMS: There will be no emergency.
GREG: Well, it's still my job to bring the situation to his notice. In my experience, when an oil shaft blows, if there is no safeguard
WILLIAMS: This is not an oil shaft, Mister Sutton.
GREG: Now you listen to me, Petra!
WILLIAMS: Must I remind you once again that I am Assistant Director of this project? You will address me in the correct manner.
GREG: All right. I'm sorry, Doctor Williams. 
WILLIAMS: Unless you grant me the respect due to my position, I shall have no choice but to report you.

[Drill head]

WILLIAMS: All safety factors have been exceeded, Director.
STAHLMAN 2: We are very near Penetration Zero. I will not decelerate at this crucial stage.
WILLIAMS: As you wish, Director.
(Stahlman goes back into the passage to the control room and leans against the wall. He pulls of his white glove to see his hand is not completely green and has also grown thick black hair.)

[Stewart's office]

(The Brigade Leader is writing.)
DOCTOR: Look, may I ask what is going to happen to me?
STEWART: You'll be shot. Eventually.
DOCTOR: Without a trial?
STEWART: This is your trial.
DOCTOR: Well, look, you can't possibly have the authority to do a thing like
STEWART: I have full authority. Defence of the Republic Act, 1943.
DOCTOR: Republic?
STEWART: Yes.
DOCTOR: Then what's happened to the Royal
STEWART: Executed. All of them.
DOCTOR: Pity. A charming family. I knew her great grandfather in Paris. Do you know, I remember on one occasion
BENTON 2: On your feet!
DOCTOR: Look, I've been standing here for quite some time.
BENTON 2: You'll be standing for a lot longer yet.
DOCTOR: Why is this place crawling with you oafs in uniform?
STEWART: You are talking of the Republican Security Forces. And the reason we are here is that this is a scientific labour camp.
DOCTOR: Staffed by slave labour, I take it? Well, you're all in very grave danger.
STEWART: We are in danger?
DOCTOR: Before that computer broke down, it was transmitting danger signals, was it not?
STEWART: You're very well informed.
DOCTOR: And what about Harry Slocum?
STEWART: What do you know about him?
DOCTOR: Only that he went berserk and started killing people.
STEWART: You condemn yourself. No one but a spy could know so much.
DOCTOR: Look, I am not a spy. I've seen it all before.
STEWART: Where?
DOCTOR: In another world.
STEWART: Very well. I can wait.
DOCTOR: You're just wasting time.
STEWART: We work to an orderly system. Your identity is being checked with Central Records. When we know who you are, the real interrogation will begin.
DOCTOR: But I don't exist in your world!
STEWART: Then you won't feel the bullets when we shoot you.
(A telephone buzzes.)
STEWART: Yes? Right, I'll be there. The prisoner will remain here.
BENTON 2: Yes, Leader.

[Central Control]

SHAW: I've just been on the telephone to Central Records about our prisoner. I gave them a full description.
STEWART: Well? Who is he?
SHAW: They've checked and re-checked. There is absolutely no one answering to his description on their files. The man does not exist.
STEWART: That's impossible!
SHAW: They'll going on checking, but they're certain that this man is not a known agent of any foreign government.
STEWART: Central Records have never been wrong before.
SHAW: He seems to know so much about this whole project, Leader, as though he'd been here for weeks. It just doesn't make sense.

[Stewart's office]

(Stewart and Shaw enter.)
STEWART: You are giving us a great deal of trouble.
DOCTOR: I'm delighted to hear that.
STEWART: You'd make things much easier for yourself if you'll tell us who you are.
DOCTOR: Proper little bureaucrat, aren't you? Can't shoot me unless you've filled in all the forms, is that it?
SHAW: Unless you co-operate, you'll soon be in front of a firing squad. You have very little time left.
DOCTOR: My dear young lady, if that computer was functioning, it would warn us that we all have very little time left!

[Central Control]

WILLIAMS: (into phone) Number two output pipe again. Is the leak bad? I see.
SUTTON: Trouble.
WILLIAMS: A minor detail.
SUTTON: At the drill head?
WILLIAMS: Yes.
SUTTON: There's no such thing as a minor detail at the drill head.
WILLIAMS: Director? They report a minor leak in number two output pipe.
STAHLMAN 2: So?
SUTTON: So something should have been done about it immediately. We are approaching final countdown.
STAHLMAN 2: Have one of the duty riggers see to it.
WILLIAMS: Yes, Director.
SUTTON: I think you should for yourself, sir. It could be important.
STAHLMAN 2: Don't presume to tell me what I should or shouldn't do, Sutton!
(Stahlman leaves.)
SUTTON: No, Director. Sorry, Director. Three bags full, Director!
(An alarm goes off.)

[Stewart's office]

STEWART: Watch him!
(Stewart and Shaw leave. The Doctor gestures Benton to come closer.)
DOCTOR: Tell me, have you ever seen anything like this before?
(The Doctor holds up his right hand, then jabs his fore and middle fingers into the top of Benton's sternum. He collapses.)

[Central Control]

(The Doctor hides round the corner in the Control room as technicians run into the drill head. Benton goes in the wrong direction. At the drill head, green ooze is coming out of the pipe by the smoking drill.)
STEWART: All security units alert. All units alert and take up emergency stations immediately. No technician will be allowed to leave his post. I say again. All security units alert. All units alert and take up emergency stations immediately.
(The Doctor crawls over to the computer.)
STEWART: No technician will be allowed to leave his post.
(The Doctor finds a tool box. A group of technicians are putting on environment suits.)
GREG: Come on, hurry up, hurry up! Get those suits on! Doctor Williams! The coolant pipes. Get me some extra power laid on for the reserve supply. Come on!
WILLIAMS: Prepare to alter your pressure readings! Begin readings at twelve! Hold your pressure at fifty. Forty.
(The Brigade Leader and a soldier have their guns ready.)
STEWART: Get back! Get back to your posts! If this place goes up, we'll all go up with it! Get back or we fire!
STAHLMAN 2: The emergency will be contained! Remain at your posts!
(Stahlman spots the Doctor searching the tool box.)
STAHLMAN 2: Benton!
DOCTOR: Come on, come on, where are you?
BENTON 2: What do you think you're doing?
DOCTOR: Trying to find a particular micro-circuit. I may be able to repair your computer for you.
BENTON 2: Outside. We've got a firing squad waiting for you.
DOCTOR: You idiot! If I don't repair this computer, you'll all be blown
BENTON 2: Look! Are you coming with me quietly, or do I shoot you here and now?

Episode Four

[Central Control]

SHAW: Just a moment, Benton. What's going on?
BENTON 2: I was about to take him out and shoot him.
SHAW: Not yet. I'll take charge of him.
DOCTOR: Thank you, Section Leader.
SHAW: I am not concerned with saving your skin, only in carrying out the correct procedure.
DOCTOR: Nevertheless, thank you, just the same. Oh, incidentally, I think I may be able to repair your computer for you.
SHAW: Leave it alone. It's none of your concern.
DOCTOR: I should say it was everybody's concern.
SHAW: Take him into the office.
DOCTOR: Wait a minute! Wait a minute, wait a minute. I think this might be it.
BENTON 2: Come on.
DOCTOR: Hang on, just a moment.
(The Doctor opens the panel on the back of the computer.)
BENTON 2: I said, come on!
SHAW: Let him try.
BENTON 2: But Leader!
SHAW: Let him try. We've got nothing to lose.
(The Doctor fits the micro-circuit, then switches the computer back on. The ticker starts rattling out information. Greg enters.)
DOCTOR: You see? The computer's already aware of the situation and is assessing its immediate problems.
(Stahlman and Petra enter.)
STAHLMAN 2: What's this man still doing here?
SHAW: He has repaired the computer, Director.
STAHLMAN 2: He shouldn't have been allowed anywhere near it. He's a dangerous spy. He sabotaged the computer.
DOCTOR: I was not sabotaging it. I was repairing it.
SHAW: The computer is working again, Director.
GREG: Well, shouldn't we see what it's got to say?
STAHLMAN 2: We are working to my calculations.
GREG: Do your calculations tell you how to deal with this emergency?
STAHLMAN 2: I have everything under control, yes.
GREG: Well, it doesn't look that way to me.
STAHLMAN 2: Watch your tongue, Sutton!
GREG: Can you transcribe what the computer's saying?
DOCTOR: Yes. The pressures and the heat are overwhelming the present velocity of the drill head.
WILLIAMS: What can we do about it?
DOCTOR: Well, you can disperse the heat and the pressure.
GREG: How?
DOCTOR: By creating a reverse vortex at the bottom of the shaft.
STAHLMAN 2: And how do we do that?
DOCTOR: Reversing all the systems.
STAHLMAN 2: And bring the whole programme to a stand-still?
GREG: It's not such a crazy idea. It's been done before.
STAHLMAN 2: With an oil shaft, Sutton.
GREG: Yes. But when everything else had failed, instead of closing down the whole shebang, someone threw everything into reverse.
STAHLMAN 2: No, it's out of the question.
GREG: At least it's worth a try. What have we got to lose?
STAHLMAN 2: We could smash the whole system.
GREG: It looks to me as if it's getting pretty well smashed up as it is now.
DOCTOR: Now look, you two are just wasting time. What I suggest is this. We push all the coolant down the output pipe and then draw up all the debris from the bottom of the shaft through the inlet pipe.
GREG: Well, what about it?
(A second alarm bell starts up.)
STAHLMAN 2: Oh, very well. Reverse all systems! Bypass number two outlet pipe.
GREG: Right! Come on, Doctor Williams.
STAHLMAN 2: And get this man out of my control area now.
DOCTOR: Of all the ungrateful nitwits!

[Stewart's office]

(Benton stands guard.)
SHAW: You seem to know a great deal about this project.
DOCTOR: Enough.
SHAW: You're a scientist.
DOCTOR: Of sorts, yes.
SHAW: Where do you come from?
DOCTOR: I've already told you. I come from a parallel space-time continuum. A twin world of this.
SHAW: If you told us the truth, there might be some hope for you.
DOCTOR: Your counterpart in the other world would tell you that I'm not in the habit of telling lies, Elizabeth.
SHAW: This other woman, the one that looks like me.
DOCTOR: It's not that she looks like you, she is you. I do wish I could make you understand this.
SHAW: What does she do?
DOCTOR: Do? She's a scientist.
SHAW: I am a security officer so there's no possible link, is there?
DOCTOR: Did you ever think of becoming a scientist? Yes. Yes, I can see that you did.
SHAW: I read physics at university. What's that got to do with it?
DOCTOR: Simply that her mind process runs along a similar parallel to yours. Doesn't that strike you as significant?
SHAW: Not particularly.
DOCTOR: Look, Elizabeth, please try and think. Whatever they taught you in this bigoted world of yours, you've still got a mind of your own. Now use it, before it's too late!

[Central Control]

GREG: Well, it seems to be working. Who was that man in the funny clothes?
WILLIAMS: They said he was a saboteur.
(The alarms stop.)
GREG: How come he saves our skin?
WILLIAMS: He's trying to save his own. Hadn't you better get number two output pipe working?
GREG: It'll mean cutting down the drill to minimum revs.
WILLIAMS: The Director won't like that.
GREG: Well then, he'll have to lump it, won't he? There's no alternative.
WILLIAMS: Sutton, if you would only curb this insolent streak, you might have a great future as a servant of the State.
GREG: What, and become a nice well-behaved little zombie, you mean, like the rest of you? No, thank you.
WILLIAMS: You've only survived so long because you have certain usefulness, because of your technical skills. Once this project is over
GREG: Greg Sutton's for the high jump. A nasty little accident in the cells, or shot whilst trying to escape?
WILLIAMS: It's been known to happen.
SUTTON: Would you care?
WILLIAMS: I'd regret the waste, that is all.

[Stewart's office]

(Shaw is using the telephone.)
SHAW: Yes, I see. Thank you. The emergency is over.
DOCTOR: Good. I'm very glad to hear it.
SHAW: Your idea worked.
DOCTOR: Maybe you'll give me a medal. Posthumously.
SHAW: You find the idea of death amusing?
DOCTOR: No, not particularly. Do you?
SHAW: If you told me the true facts about yourself, I may be able to help you.
DOCTOR: Elizabeth, I am trying to help you! You said the emergency was over. Well, it isn't. As long as you people go on drilling, you're rushing into terrible danger!

[Drill head]

STAHLMAN 2: Sutton? How long?
GREG: Almost finished.
STAHLMAN 2: Good, then we can continue with the drilling.
GREG: At reduced revs?
STAHLMAN 2: No, I intend to accelerate again as soon as possible.
GREG: Well, I don't advise it.
STAHLMAN 2: I don't need advice.
GREG: Except from that prisoner!
STAHLMAN 2: I would have come to the same conclusions.
GREG: You may have come to them a bit too late.
STAHLMAN 2: I sometimes wonder why I tolerate you, Sutton.
GREG: That's easy. On a project like this you don't just need a good party member, you need a good engineer.
STAHLMAN 2: Oh, you are useful, but you're not indispensable.
GREG: It seems to be my day for getting warnings.
STAHLMAN 2: You have a bad record, Sutton, a long history. It would be very easy to have you disposed of. Remember that.
(Out in the corridor, Stahlman stops and clutches his head in pain.)

[Stewart's office]

(The Doctor is getting the third degree, complete with bright light in the face. He is slumped in a chair, exhausted.)
SHAW: Name?
STEWART: Who sent you here?
SHAW: Did you come to commit sabotage?
STEWART: Name?
SHAW: What organisation employs you?
STEWART: When did you first become a traitor?
SHAW: How did you get into the complex?
STEWART: Who helped you? Was it Sutton?
SHAW: Name? What is your name? Answer!
DOCTOR: You're wasting your time, you know. I can stand a great deal of this childishness.
STEWART: This is only the beginning.
SHAW: We have other methods.
DOCTOR: Yes, I'm sure you have. But it won't do you any good.
STEWART: You'll talk, eventually.
SHAW: Everybody talks.
DOCTOR: How can I give you information that doesn't exist?
STEWART: The information must exist and you will give it to us!
SHAW: Name?
STEWART: Who sent you here?!
SHAW: Which of our enemies are you working for?
STEWART: Who are your associates?
DOCTOR: I came here on my own. I came by accident. I came here. The Tardis console slipped me sideways in time. Slipped me sideways in time.
SHAW: Shall we proceed to stage two interrogation? He's just babbling.
STEWART: No, he's a tough one. He might die before he talked.
SHAW: Yes. We'd better let him get his strength back.
(The sound of the drill rises.)
DOCTOR: That Stahlman. He's accelerating the drilling.
STEWART: All right, we'll start again, shall we?
SHAW: Who sent you here?
STEWART: Why did you come?
(Stahlman enters and turns on the main light.)
STAHLMAN 2: Well, what progress have you made?
STEWART: As you can see, Director, the prisoner is still being interrogated. Proceeding according to plan!
DOCTOR: I see you're wearing white cotton gloves, Director. May we ask why?
STAHLMAN 2: You're allowing the prisoner to be impertinent?
DOCTOR: Brigade Leader, ask him to take off his left glove. I think you'll find it very interesting.
STEWART: Director?
STAHLMAN 2: Well, they say a madman should be humoured.
(Stahlman has bandages under the glove.)
DOCTOR: Why the bandages, professor?
STAHLMAN 2: I scorched my hands.
DOCTOR: You touched some of that green substance, from that cracked jar, didn't you? Just a little, but it's enough to infect you.
STEWART: Benton! Take him away, down to the security cells.
DOCTOR: Listen to me. You're seriously ill. You've been infected.
STAHLMAN 2: Take him away.
DOCTOR: Listen to me, Stahlman, for God's sake.
(Benton hauls the Doctor out.)
STEWART: You will supervise the transfer of the prisoner to the security cells.
SHAW: Very well, Leader.
STEWART: At once, if you please!
SHAW: Yes, Leader!
(Shaw leaves.)
STEWART: You're taking a great deal of interest in this prisoner, Director?
STAHLMAN 2: For security
STEWART: Security? Is my responsibility.
STAHLMAN 2: Since you allowed the man to enter the complex and roam about at will
STEWART: The man was caught! He is no longer a danger to us. The people who sent him, how and why he came here, this information is vital.
STAHLMAN 2: Then you'd better get him to talk, and do it quick. Before the day is over, I want him liquidated.

[Central Control]

WILLIAMS: (into phone) If it decreases, let me know at once. Thank you.
GREG: Doctor Williams, I think we should have checked the whole system from top to bottom while we had the drill at minimum revs.
WILLIAMS: Director Stahlman knows what he's doing.
GREG: You all make a little tin god of that Stahlman. Well I think he's a nut.
WILLIAMS: That sort of remark's dangerous.
GREG: I tell you, Stahlman's a nut. Well? Aren't you going to report me? Get me a week in the punishment cells? Things are looking up. A couple of days ago, you'd have reported me without a second thought.

[Security cells]

(A row of barred cells, no privacy. A figure stirs under a blanket in the first one.)
DOCTOR: Please, don't push. I'll have you know that your counterpart in the other world was a nice, sociable sort of chap, Sergeant.
BENTON 2: My rank is Platoon Under Leader.
DOCTOR: That's a bit of a mouthful, isn't it?
BENTON 2: Your trouble is you talk too much.
DOCTOR: Ah, I see I've got company. And what did he do, park in a restricted zone?
BENTON 2: Stop asking stupid questions! 
DOCTOR: At least he seems to be sleeping peacefully.
BENTON 2: He's had a tranquilliser dart. They don't give us any trouble after that. We should have done the same to you.
(The Doctor is pushed into the middle cell.)
BENTON 2: Now, get in.
DOCTOR: What about some food? A cup of tea? Some cocoa? A glass of water then?
BENTON 2: This way, Leader. Cell two.
DOCTOR: Ah. Visiting time already, is it?
SHAW: Your interrogation isn't over yet.
DOCTOR: Oh yes, it is.
(The Doctor lies down on the bunk.
) BENTON 2: Get on your feet when the Section Leader's talking to you!
DOCTOR: Ah, go away and give me some peace.
BENTON 2: When I say get on your feet, prisoner, I mean get on your feet!
(Benton is pointing his rifle through the bars.)
DOCTOR: Oh well, that's different. Anything for a quiet life.
SHAW: Now we'll start again. Who are you? How did you get into the complex?
DOCTOR: Look, I am sick and tired of answering all these idiot questions.
SHAW: The questions will go on until you answer them.
DOCTOR: I have answered them! More times than I care to remember.
SHAW: You have told us nothing.
DOCTOR: I've told you the truth. If your minds are too narrow to accept it, that's not my fault.
BENTON 2: Give us a few minutes with him, Leader.
SHAW: No. Wait outside, in the corridor, both of you.
(Benton and the squaddie leave.)
SHAW: Now, perhaps we can talk reasonably.
DOCTOR: Trying a change of technique?
SHAW: If you like.
DOCTOR: First you try to bully me, and then you switch on the charm. Secret police routine seven stroke four.
SHAW: Believe me, I really am trying to help you.
DOCTOR: Even though I'm a spy?
SHAW: No. No, you're too conspicuous to be a spy. No, I've got a theory that you're from one of these crackpot free speech groups, trying to make some crazy demonstration. 
DOCTOR: Oh, no!
SHAW: Look, if you'll give me a full confession, I may be able to convince them that you're some harmless lunatic. You'll get away with a few years in a labour camp.
DOCTOR: Look, I am not mad, I am not a spy and I'm certainly not a political demonstrator. You just won't listen, will you?
SHAW: I can see I've been wasting my time. I'll leave you to the Brigade Leader. He'll get the truth out of you.
DOCTOR: Your counterpart had some intelligence. I wish I could say the same for you.
(Shaw leaves.)
DOCTOR: Hello, old chap. How are you doing? Been down here long, have you? Read any good police records lately? The friendliness of this establishment overwhelms me. 
(The Doctor lies down with his back to the other cell. We see a green hairy hand come out from underneath the blanket.)

Doctor's workshop]

BRIGADIER: I'm sorry, Liz, but my men have searched the entire complex thoroughly. There's no sign of the Doctor.
LIZ: I didn't think there would be.
BRIGADIER: Maybe that wretched machine of his has dumped him a few miles away.
LIZ: It's not as simple as that, Brigadier. He's somewhere in space or time.
BRIGADIER: Well, wherever he is, or whenever he is, he can look after himself.
LIZ: He's not indestructible, you know.

[Central Control]

GOLD: Professor Stahlman, could you spare me a moment?
STAHLMAN: Run out of paper work?
GOLD: Please, this is important.
STAHLMAN: Just a moment. Well?
GOLD: Any problems with the accelerated drilling?
STAHLMAN: No, none at all. I didn't expect any.
GOLD: Well, I assume you'll be taking extra precautions as we approach penetration zero?
STAHLMAN: I shall do what I think best. What is it you want?
GOLD: I have a car outside waiting to take me to London, and an appointment with the Minister later on today.
STAHLMAN: Well, have a pleasant journey.
GOLD: Unless you can give me certain reassurances, I shall feel bound to convey to the Minister the full extent of my anxieties.
STAHLMAN: What anxieties?
GOLD: Oh, come now, Professor! You know what I mean.
STAHLMAN: No, I don't. Perhaps you'd explain exactly what you do mean.
GOLD: We must slow down drilling as we approach penetration. We need extra safety precautions and a failsafe mechanism to close down completely if necessary.
STAHLMAN: Now, Sir Keith, if you'd had your way, we would never have started this project.
GOLD: I am not saying
STAHLMAN: Now you want us to proceed at a snail's pace like a pack of cautious old women.
GOLD: I want this project to succeed as much as you do, but we must act like responsible scientists.
(Liz and the Brigadier enter.)
STAHLMAN: You accuse me of irresponsibility? I conceived this project, I fought for Government backing and I shall carry it through to success in spite of all your efforts to stop me.
GOLD: No one's trying to stop you.
STAHLMAN: You've consistently obstructed my work. You've caused delay after delay and I won't put up with this interference any longer.
GOLD: Oh, very well, Professor, you leave me no alternative.
STAHLMAN: You can tell the Minister what you like. He at least is aware of the importance of my work.
(Stahlman leaves.)
BRIGADIER: He doesn't get any better tempered, does he?
GOLD: The man's impossible.
LIZ SHAW: Do you think the Minister will listen to you?
GOLD: Well, he's an old friend of mine, but Stahlman's dazzled him with promises. Limitless cheap power for the whole country.
BRIGADIER: Will you be back in time for penetration zero?
GOLD: Yes, of course. Though I can't say I'm looking forward to it very much.
LIZ SHAW: Why not?
GOLD: Well, it sounds ridiculous, but there's something ominous about the whole project. Your friend the Doctor felt it too. By the way, where has he gone?
BRIGADIER: We're not quite sure.
GOLD: Well, he's better off out of it, wherever he is.

[Security cells]

(The other prisoner is making strange noises. It wakes the Doctor.)
DOCTOR: Sergeant. Sergeant! Sergeant!
SENTRY: What's the noise all about?
DOCTOR: This man is sick. He needs medical attention.
SENTRY: If you don't shut up, I'll shut you up!
(The Sentry unlocks the first cell and goes in.)
SENTRY: Listen.
(He pulls back the blanket. It is green Bromley, who promptly attacks the sentry, knocking him out or more likely killing him. Then he pulls apart the bars dividing his cell from the Doctor's. The Doctor uses his mattress to push Bromley aside, slip through the bars and out of the first cell, locking it behind him.)

[Complex grounds]

(The Doctor runs past buildings, dodging patrols. He watches a civilian worker get into a Land Rover.)
SOLDIER: By the right, right wheel!
(The Doctor climbs into the back of the Land Rover as the troop marches down the line of buildings and he is driven away.)

[Central Control]

(The clock reads 0:35:42 and counting.)
GREG: Is everything ready?
WILLIAMS: All systems have been checked and are functional.
GREG: We'd better cross our fingers.
WILLIAMS: We depend on science, Mister Sutton, not superstition.
GREG: We could do with some plain old fashioned luck as well. Where's the Director?
WILLIAMS: He'll be here.
GREG: Well, I wish I wasn't. Something's wrong, something's just not adding up.
WILLIAMS: What can go wrong?
GREG: Perhaps we should try asking the computer.
(As he is driven along, the Doctor finds protective clothing in the back of the Land Rover. Benton discovers the sentry in the cells. The Doctor has put on the protective suit, and dons the helmet as a troop of soldiers march towards the now parked Land Rover.)

[Central Control]

COMPUTER: Zero minus three minutes, zero seconds. Condition Red Two now commencing.

[Complex grounds]

(Five more men in protective suits have arrived.)
SOLDIER: Right, you all ready? Let's go, at the double.
(Two men stop and let the Doctor out of the Land Rover.)

[Central Control]

COMPUTER: Zero minus two minutes, ten seconds. Disaster crew at action stations. Zero minus two minutes, zero seconds and counting. Condition Red Three now commences.
(The Brigade Leader walks along a line of soldiers.)
COMPUTER: Zero minus one minute, fifty seconds. Final re-check, all monitoring circuits. Zero minus one minute, forty seconds. Technical personnel at final stations.
(The disaster crew in their protective suits enter. The Doctor hangs back.)
COMPUTER: Zero minus one minute, thirty seconds. Final power build up now completed.
(The Doctor joins the rest of the crew.)
COMPUTER: Zero minus one minute, twenty seconds. Non-technical staff to safety positions. Zero minus one minute, ten seconds. All systems check for final countdown.
(The Doctor goes over to a computer console.)
COMPUTER: Zero minus one minute, zero seconds and counting.
STEWART: You there!
COMPUTER: Final countdown commences now.
STEWART: Come down here.
COMPUTER: Zero minus fifty seconds. Stand by.
STEWART: Did you hear what I said? Come down here.
COMPUTER: Zero minus forty seconds.
(The Doctor removes his hood and the Brigade Leader starts fumbling for his pistol.)
DOCTOR: You must stop this countdown before it's too late!
COMPUTER: All personnel stand by.
DOCTOR: Do you hear me? You must stop it!
STAHLMAN 2: Brigade Leader, shoot that man now!
GREG: You can't do that! It's just murder!
DOCTOR: If you break through the Earth's crust now, you'll release forces you never dreamed could exist!
COMPUTER: Zero minus thirty seconds. Countdown moves to final phase.
(The drill head starts making a nasty noise.)
DOCTOR: Listen to that!
COMPUTER: Zero minus twenty seconds.
DOCTOR: That's the sound of this planet screaming out its rage!
COMPUTER: Countdown will now proceed by seconds.
STAHLMAN 2: I order you to shoot that man!
(As Stewart takes careful aim, Greg Sutton grabs his arm and pushes it down.)
GREG: Go on, run for it! Run!
(But the Doctor's escape routes are blocked by soldiers.)
COMPUTER: Zero minus ten seconds. Nine. Eight.
(Stahlman picks up Stewart's pistol just before the Doctor can.)
COMPUTER: Seven, six, five, four, three, two, one, zero.

Episode Five

[Central Control]

COMPUTER: We have Penetration Zero!
(KaBOOM! Everyone is knocked off their feet. Technicians run for their lives.)
STAHLMAN 2: Don't panic! Get back to your posts!
(Benton points his rifle at Greg.)
GREG: Look, I've got a job to do here!
STEWART: Never mind him! Stop those technicians!
(The military go after the technicians.)
WILLIAMS: Are you all right, Director? 
STAHLMAN 2: Yes, yes. Check all the other systems.
WILLIAMS: Yes.
(The Doctor gets up and sees Greg putting on an environment suit.)
DOCTOR: You're not thinking of going in there, are you?
GREG: Don't worry, I've never seen a bore I couldn't cap yet.
DOCTOR: There's never been a bore like this one.
GREG: The first thing we've got to do is get in there and check the main valve and get the coolant reserve flowing.
(Stahlman walks towards the drill head.)
GREG: Stahlman! If you're thinking of going in there, you'd better put this suit on!
DOCTOR: Somehow, I don't think he feels the heat as we do.
(Stahlman walks off with a suit.)
SHAW: Can they contain the emergency from here?
WILLIAMS: No, they have to go for the actual drill head.
(Somewhere in the complex, a storage tank explodes. Green ooze is still coming out of the smoking drill head.)
GREG: Come on, Doctor.
DOCTOR: Well, here goes.
(They put on the protective hoods and go into the drill head. Greg goes straight to a big red wheel valve while the Doctor checks the various people lying around. Stahlman, also in a suit, thumps Greg over the back of the head with an iron bar, takes off his hood and starts to drag him away. The Doctor rushes over to grapple with Stahlman, and gets thrown onto his back several times. Greg gets up and hits Stahlman with the bar. The Doctor helps him out of the drill head and back into the control room.)
GREG: Oh, what the devil hit me?
DOCTOR: A piece of pipe held by Stahlman.
GREG: Stahlman hit me?
WILLIAMS: Is the Director still in there?
DOCTOR: Yes.
SHAW: Why didn't he come out with you?
DOCTOR: I think he likes it in there.
GREG: The main coolant valve's seized. I can't flood the drill head area.
WILLIAMS: We've got to get the Director out.
DOCTOR: Yes, not to mention those technicians.
GREG: Right, let's have another go.
(The blast doors are closing.)
GREG: Oh, what the heck's going on? Well, that's crazy!
WILLIAMS: They've closed it from the inside. Bypassed the control and locked down on manual!
(At the drill head, Stahlman drags a technician to the drill itself and rubs his face in the green ooze.)
SHAW: What does it say?
(The Doctor and Greg are out of their environment suits. The Doctor is reading the computer printout.)
DOCTOR: Very little now, I'm afraid. Tell me Mister Sutton, how thick are those walls?
GREG: Thick enough. ferrous concrete, steel plating, asbestos sheeting, the lot. It could stand up to an atomic blast.
DOCTOR: Compared to the forces that you people have unleashed, an atomic blast would be like a summer breeze.
(And as if to prove it, we see more parts of the complex with thick red smoke pouring out. Stewart and Shaw enter.)
DOCTOR: What's going on out there?
STEWART: The technicians and staff have got away. Most of my security guards have gone with them.
GREG: Perhaps they're the sensible ones.
DOCTOR: Yes, well, they'll be no better off in the long run, wherever they go.
WILLIAMS: Doctor, I'm afraid the computer's finally broken down.
STEWART: It is your duty to remain.
SHAW: That's correct.
DOCTOR: Well, the heat will have fused the main circuits. I'll have a look.
WILLIAMS: Brigade Leader?
STEWART: Yes, Doctor Williams?
WILLIAMS: Any news from London yet?
STEWART: Massive seismic disturbances reported throughout the country. Earth tremors reported in the Midlands and as far north as Leeds.
GREG: Just what are the authorities doing?
SHAW: They've ordered an immediate evacuation of the area except for essential personnel. The Brigade Leader is to assume executive control.
GREG: Anything else?
SHAW: No, after that the line went dead.
GREG: So they're abandoning us. They're not even going to try and seal the shaft.
SHAW: They believe that the emergency will eventually pass over.
GREG: Well, the Doctor doesn't seem to think so.
STEWART: Oh, who cares what he thinks.
GREG: I do. He talks a lot of good sense! Doctor?
DOCTOR: Yes?
GREG: Surely there must be some way of sealing the shaft? Why don't the government evacuate us all and blow up the whole area?
DOCTOR: Too late, Mister Sutton. You've unleashed the energies of the Earth's core.
GREG: All right, but we must cap the bore somehow.
DOCTOR: No substance on this Earth is strong enough to withstand those pressures.
GREG: Okay, so what's going to happen?
STEWART: Well, Doctor, what is going to happen?
DOCTOR: Well, the heat and the pressures'll continue to build up until the Earth dissolves in a fury of expanding gasses, just as it was billions of years ago.
SHAW: How long have we got?
DOCTOR: Maybe a few weeks, maybe only a few days.
GREG: So it's Doomsday? We just sit back and wait for it.
(Green Bromley enters. Everyone goes for cover except the Brigade Leader, who draws his pistol.)
DOCTOR: Don't go near him, Brigadier! Don't go near him. He's probably more interested in getting to the drill head than he is in us.
(But the Brigade Leader still shoots at Bromley as he makes his way across the floor of the control room. But before Bromley can get to the soldier, the Doctor uses a CO2 extinguisher on him.)
DOCTOR: Oh. He seems to be dead this time.
STEWART: Rather surprising.
DOCTOR: It wasn't just your bullets that killed him, you know.
STEWART: The fire extinguisher?
DOCTOR: Yes, the fire extinguisher. They can't stand cold.
GREG: Well, that's enough for me. There's no point in us hanging around any longer.
STEWART: If you're thinking of deserting.
GREG: Evacuating is the word. If I've only got a little time left to live, I'm going to spend it as far away from this place as I can get!
SHAW: We were ordered to remain here.
STEWART: And that's exactly what we're going to do.
GREG: You speak for yourself!
STEWART: You still have a job to do here, Sutton!
GREG: You just don't listen, do you? You heard what he said. There's nothing we can do. Is that right, Doctor?
DOCTOR: Yes, I'm afraid so.
GREG: Well, I'm clearing out! Coming, Petra?
STEWART: You will stay here and do your duty!
GREG: You're still loyal to your glorious republic. I'd like to know what your precious dictator can do for you now.
STEWART: I will not listen to treason!
DOCTOR: Gentlemen, stop arguing. Just save your energy.
GREG: For what? We're all under sentence of death. Oh, come on, Petra.
BENTON 2: I've managed to round up a few of the men, Leader.
STEWART: Good. Post them outside. No one is to leave this building without my permission. No one, Benton!
BENTON 2: Understood, Leader.
GREG: You know it's marvellous, isn't it? The world's going up in flame and they're still playing at toy soldiers!

[Outside Central Control]

(Benton sees some soldiers lounging around by an tank.)
BENTON 2: You lot! Fall in on the double!

[Central Control]

(Williams is trying to repair the computer.)
GREG: Pack it in. It's no good.
WILLIAMS: We can't be sure of that.
GREG: You heard what the Doctor said. The heat will have fused the main circuits.
WILLIAMS: The Doctor has no control here.
GREG: You could have fooled me.
WILLIAMS: It's not his responsibility.
GREG: Maybe not, but he's the only one who seems to know what's going on.
WILLIAMS: Thank you, Mister Sutton.
GREG: Oh, I'm not getting at you, but if the Doctor's right, you're wasting your time.
WILLIAMS: Look, if I can get this computer working again, it might give us the solution.
GREG: Still hasn't sunk in, has it? There is no solution! The whole place is going to blow up.
WILLIAMS: The whole system needs rewiring.
GREG: And no one is being allowed in or out of this place. Do you get the point now?
WILLIAMS: What point?
GREG: Those blokes in London know it's no use. If they thought there was any chance, this place would be crawling with experts. You'd have as much equipment as you need.
WILLIAMS: It might be on its way.
GREG: Nothing's on its way! We've been left here to die.
WILLIAMS: I don't believe that.
GREG: Oh yes, you do. Because it's logical. They're scared to let us out of here because we'll increase the panic.
WILLIAMS: They wouldn't just abandon us. They'd evacuate us if things got too dangerous.
GREG: Maybe you're right. Let's hope so.
WILLIAMS: You really think this is the end, don't you?
GREG: It could be.
WILLIAMS: We're just going to die in here. I can't take it in.
(Greg puts his arm around her.)
GREG: Look, I'm sorry but there are times when it's better to face the truth.
WILLIAMS: Oh, Greg, I'm frightened!
(They embrace.)
WILLIAMS: What can we do?
GREG: Well, the question really is, what you're going to do.
WILLIAMS: What do you mean?
GREG: Well, I'm going to get out of here. I could do with some help from you.
WILLIAMS: From me?
GREG: Well, what about it? Are you going to be a nice well-behaved little zombie or are you going to join the rebels?

[Stewart's office]

SHAW: There's nothing we can do. Absolutely nothing!
DOCTOR: You could help me to save a world, you know.
SHAW: You said we'd passed the point of no return.
DOCTOR: Not this one, Elizabeth. The other one.
STEWART: Even now, you stick to this absurd story.
DOCTOR: This other world exists, Brigade Leader. It's as true as the one you know yourselves.
SHAW: And we're all somehow duplicated there?
DOCTOR: Yes. You, the Brigade Leader, Stahlman, Sutton, Petra, all of you. You could save your other selves.
SHAW: Save them? How?
DOCTOR: With the aid of the Tardis.
STEWART: Tardis?
SHAW: You mean that odd-looking contraption we found in the hut?
DOCTOR: Yes.
SHAW: Could it take you back?
DOCTOR: Yes, possibly. If I could use your nuclear reactor for power.
SHAW: But if this other world is parallel, they'll be in same situation as us.
DOCTOR: Not necessarily. Work on their project is not so advanced as yours. I may be able to stop them before they penetrate the Earth's crust.
STEWART: I think we'll take another look at this wonderful machine of yours.

[Central Control]

WILLIAMS: Brigade Leader, for your information, all systems are breaking down.
STEWART: Remain here. We shall return shortly.
GREG: I wonder where he's off to?
WILLIAMS: Can't we try and get out now?
GREG: Well, you heard what he said. All the exits are being guarded by a bunch of trigger-happy thugs.
WILLIAMS: They might let us through.
GREG: And they might shoot us out of pure nervousness. Just wait our chance. Don't worry, Petra. When the time comes, we'll get out of here and it'll take more than a bunch of tin soldiers to stop us.

Doctor's workshop]

STEWART: You expect us to believe that you came here in this?
DOCTOR: That's right.
SHAW: But this isn't a vehicle at all.
DOCTOR: No, but she's a very important part of one.
STEWART: And where's the rest of it?
DOCTOR: Back in the world where I came from. I, er, I removed the console to make some trial runs.
(The Doctor powers up the console.)
STEWART: Well, what's happening?
SHAW: You said you needed a power source to make this thing work.
DOCTOR: There's always a certain amount of energy left in the storage unit.
STEWART: I think we've seen enough of this nonsense. Come on.
DOCTOR: You said you were going to help me.
STEWART: I said nothing of the kind. This contraption is obviously incapable of taking anyone anywhere. We shall return to Central Control.
DOCTOR: If you'd only try and use the little intelligence you have.
STEWART: I've no time for fairy stories.
SHAW: If you could give us some proof, Doctor. A demonstration.
DOCTOR: Proof? Demonstration? What do you think I am, a conjuror? Have can I give you a demonstration when I haven't got. Now, wait a minute.
STEWART: Well?
DOCTOR: If I'm to do it, I'll drain the storage unit completely. Very well, you shall have your demonstration.
(The Doctor activates the console and he dematerialises with it.)
STEWART: Doctor? Doctor?
(And rematerialises.)
DOCTOR: Well, are you satisfied? Or do you think it was all done with mirrors?
SHAW: What happened? Where were you?
DOCTOR: Just a pitiful few seconds into the future. I only wish it could have been more.
STEWART: Stay away from that!
DOCTOR: Don't be a fool, man. I can't possibly go anywhere. The storage unit is completely flat.
STEWART: If the power was connected, you could make the journey back?
DOCTOR: Perhaps.
STEWART: And take others with you.
DOCTOR: No! No, I couldn't possibly do that.
SHAW: Why not?
DOCTOR: It would create a dimensional paradox. It would shatter the space-time continuum of all universes.
STEWART: If you can save yourself, you can save us.

[Outside Central Control]

(To a background of loud rumbling, the squaddies are chatting.)
BENTON 2: Squad! 'Shun! As you were! 'Shun! Stand at ease! Don't move.

[Central Control]

STAHLMAN 2 [OC]: Doctor Williams. The argh. Oh. Argh.
WILLIAMS: Greg? Greg? Greg!
GREG: What's up? I was disposing of that thing's body.
WILLIAMS: I just heard something from the intercom.
GREG: Not a chance. They're all done for in there.
WILLIAMS: You come and listen.
(But the speaker is just buzzing.)
WILLIAMS: I did hear something.
STAHLMAN 2 [OC]: Argh. Oh, oh.
(Stewart, the Doctor and Shaw enter.)
GREG: We've just heard something from the drill head.
SHAW: That's impossible. They must all be dead in there.
WILLIAMS: I tell you we heard something.
STAHLMAN 2 [OC]: Doctor Williams! Can you hear me? Raise the heat shield! Manual controls are jammed with the heat.
WILLIAMS: The Director.
STAHLMAN 2 [OC]: Can you hear me, Doctor Williams? Let us, let us out! Argh.
WILLIAMS: It is the Director! We've got to do what he says and let him out of there.
DOCTOR: You mustn't!
WILLIAMS: But he's alive.
DOCTOR: No! Whatever you do, don't raise that heat shield.
STEWART: If the Director's found a solution, then we need him out here. Now stand back, Doctor.
WILLIAMS: He must have unlocked the manuals. The controls are working.
(The blast door opens part way, then a green hairy figure pushes it up to the top.)
WILLIAMS: Director!
DOCTOR: No! Don't go anywhere near him. Don't go near him.
WILLIAMS: But he needs help!
(The figure takes off its environment suit hood. Stahlman 2 is fully changed into a green hairy monster. He summons the others out of the drill head. Meanwhile, Benton enters Central Control.)
STEWART: Why don't they attack?
DOCTOR: They're acclimatising themselves. They don't want to get too far away from the heat.
GREG: Let's get out of here.
(The humans make a dash, but the Greens cut them off and corral them.)
GREG: The other way!
STEWART: Now they've covered both exits.
DOCTOR: We'll make a break for your office.
STEWART: Benton, get out!
(Too late. Benton is grabbed by the Greens and dragged towards Stahlman.)
BENTON 2: Please, no! No, no! No, no, no, no, no!
(Stahlman strokes his hand over Benton's face, and Benton collapses, screaming. The Doctor opens a hatch in the computer console and pulls out a red wire. The blast door closes. The Greens rush over to it.)
DOCTOR: Into the office!
(Greg runs to Benton.)
DOCTOR: Leave him be! There's nothing you can do! Come on, hurry!
(The Doctor slams the door in Green 40653's face. Benton writhes around on the floor, rapidly transforming into another hairy Green.)

[Stewart's office]

GREG: Well, we shouldn't have just left Benton! You don't mind sacrificing your men, do you, Brigade Leader?
DOCTOR: Believe me, Mister Sutton, there was nothing we could have done.
GREG: Well not now, there isn't. He's probably been killed by those things!
DOCTOR: Worse than that, he'll have become one of them. The heat will accelerate the process.
GREG: Well, why did you cut them off from the drill head?
DOCTOR: To keep them away from the heat. The hotter it is, the stronger they grow.
GREG: Well, if it gets any hotter in here, they won't have to attack. We'll just shrivel up.
STEWART: Well, Doctor, it doesn't look as though your space craft is going to be much good to anybody now.
GREG: Space craft?
WILLIAMS: What are they talking about?
SHAW: The Doctor has some sort of device that could get him out of here.
STEWART: Only the Doctor, of course. Not the rest of us.
SHAW: He says he comes from a parallel world.
GREG: Look, will somebody tell me what's going on?

[Gold's car]

(Across the dimensions, Gold is reading the Financial Times whilst being chauffeured back to the complex.)
GOLD: Where are we, Patterson? I don't recognise this.
PATTERSON: Different route, sir. Trying to avoid the traffic.
(Gold tries to use the car phone.)
GOLD: What's the matter with this thing?
PATTERSON: No idea, sir. It was working on the way up.
GOLD: It took me a day's hard talking to convince the Minister, now I can't even get in touch with the complex.
PATTERSON: Are they going to slow down the drilling, sir?
GOLD: They're going to suspend it, pending a full review of the project. Where the devil are we? It looks like the middle of nowhere. All right, Patterson, what's going on?
PATTERSON: I'm sorry, sir. I don't understand.
GOLD: (Sharply.) Answer me, please.
PATTERSON: Orders, sir.
GOLD: From whom? Professor Stahlman, wasn't it.
PATTERSON: Yes sir.
GOLD: Was I ever supposed to get back from the Ministry?
PATTERSON: Not if you were successful, sir. I was to drive as far off the route as I could and stage a breakdown.
GOLD: The man's raving mad.
PATTERSON: He threatened to have me sacked, sir.
GOLD: Well, you realise now that I have the Minister's full authority behind me.
PATTERSON: Yes, sir.
GOLD: All right. If you can break all records getting back to the complex, I might just forget about all this.
PATTERSON: Thank you, sir, I'll be very grateful.
GOLD: So you should be. Now put your foot down.
PATTERSON: Sir, I'd, er, I'd like you to know that I objected to the order, sir.
GOLD: Keep your eyes on the road! Look out!
(Oncoming headlights dazzle Patterson. There is a screech of rubber on tarmac.)

[Stewart's office]

(The Greens regain their strength and go to the office door.)
STEWART: So, we're expected to sacrifice all our lives so as the Doctor can get back to his other world.
SHAW: We haven't got any lives to sacrifice. It's only a question of time.
WILLIAMS: What do you think, Greg?
GREG: It's the weirdest story I've ever heard, but I'm prepared to believe the Doctor.
SHAW: You're outvoted, Brigade Leader.
STEWART: It makes very little difference as we're all trapped in here anyway.
DOCTOR: Not necessarily. I do have a plan for getting us out, but it all depends on those creatures out there.
(Those creatures manage to smash the small glass window in the office door.)

Episode Six

[Stewart's office]

(The Doctor pulls Greg back.)
DOCTOR: No, no! No, don't touch it. 
(The Doctor lets off a fire extinguisher through the broken glass.)
DOCTOR: I don't think they'll be back for a while. They'll wait till the temperature rises.
SHAW: How long have we got?
DOCTOR: I should say all of ten minutes.
GREG: You said you had a plan just now. What is it?
DOCTOR: Well, if we're going to get power to the Tardis console, we'll have to connect it up to the nuclear reactor.
WILLIAMS: That's if there's any power left.
(The Doctor holds his handkerchief up in front of the air conditioning grille. It moves.)
SHAW: What are you doing?
DOCTOR: Well, the air conditioning's still working, so power's still getting through.
WILLIAMS: Only the bare minimum. The reactor must still be working off robot control.
DOCTOR: Can you boost the output?
WILLIAMS: Well, in an emergency, the master switch automatically shuts down the reactor banks.
DOCTOR: But it can be re-set?
WILLIAMS: It would take time. And after that I'd still have to get to the main switch room at the reactor.
GREG: The master switch is in Central Control. How do we get through that lot?
DOCTOR: Well, we've still got a weapon to use against them.
SHAW: You mean the pistol?
DOCTOR: No, I don't. I mean the fire extinguisher.
SHAW: You can't hold them off with that thing for very long.
WILLIAMS: If that master switch has been damaged, it'll be a long job resetting it.
DOCTOR: Well, there are other fire extinguishers in Central Control.
GREG: If we can get to them. Wait a minute! I'm a fool. Of course! The coolant reserve. I've rigged up an emergency hose.
WILLIAMS: That's it! Well, the coolant's under pressure! It's just as cold as the CO2 in the fire extinguishers.
GREG: Doctor, you've got a monster sized fire extinguisher just waiting for you in there.
DOCTOR: Splendid. Well, we'll fight our way into Central Control using this. While Mister Sutton holds them off with his coolant, I'll repair the master switch.
(A Green tries to put its arm through the window again. Greg uses the extinguisher while the Doctor gets to the door bolt.)
DOCTOR: Right. Now!
(The Doctor opens the door, the Greens rush in only to be driven back by Greg and the CO2.)

[Central Control]

(Everyone dashes over to a power cable under some flooring. Greg hands over the extinguisher to the Brigade leader.)
STEWART: Hurry up, Sutton!
GREG: I'm going as fast as I can. Everything's red hot.
(Stahlman is creeping into the room from behind them.)
STEWART: I can't breathe!
DOCTOR: Well, stop talking so much.
SHAW: Look out!
(Stahlman heads for the Doctor and Greg, and Stewart takes him down with the CO2 then turns back to the other Greens.)
DOCTOR: That's enough. Don't waste it! That's enough, I said! It's Stahlman!
WILLIAMS: Is he dead?
DOCTOR: No, I think he's just paralysed. He'll probably come to again when the temperature rises.
GREG: Petra, give me a hand here!
STEWART: Sutton, get that hose going!
GREG: I can't. It's seized up!
STEWART: Well, what do we do now?
(The Doctor grabs a wrench from a tool box and takes it to Greg, dodging Stahlman's grasping hands.)
DOCTOR: Right.
SHAW: Brigade Leader!
(Stewart uses the last of his CO2 on the Greens.)
GREG: They're coming!
(Greg snatches up the end of the long hose and waves it at the Greens. Coolant vapour drives them back against the wall.)
DOCTOR: Right, off you go!
SHAW: What about you?
DOCTOR: Don't worry about me. I'll stay and repair the master switch.
WILLIAMS: Greg!
GREG: I'll stay with the Doctor.
STEWART: Come on, let's get going!
GREG: Go on. I'll cover you!
(Stewart, Shaw and Williams run out.)
GREG: Okay, Doctor, get on with it.

[Outside Central Control]

(The whole area is red hot and looks like a furnace.)
STEWART: It is hot out here.
WILLIAMS: I still find it impossible to breathe.
STEWART: Well, no use hanging about.
SHAW: We've got to wait for them!
STEWART: We must get right away from here.
SHAW: Wait for them.
STEWART: They'll find us.
WILLIAMS: You go if you want to, Brigade Leader.

[Central Control]

DOCTOR: The heat's made a pretty good mess of this.
GREG: It's making a mess of me too,
DOCTOR: You can always join the others outside, you know, Mister Sutton.
GREG: I think I'll hang around a bit longer. The natives are getting restless again.
DOCTOR: Are they now?
GREG: How are you making out?
DOCTOR: Slow but sure, Mister Sutton.
GREG: Doctor?
DOCTOR: Mmm hmm?
GREG: When you get back to that other place.
DOCTOR: If I get back.
GREG: How are you going to make sure they stop their drilling?
DOCTOR: I don't know. Maybe somebody will listen to me there. Sir Keith, for instance?
GREG: But he's dead.
DOCTOR: Here, perhaps. In the other world, maybe not.

[Brigadier's office]

BRIGADIER: (into phone) That's absurd! There must be some trace. People don't just vanish! Well, keep looking. Let me know when you have any news.
(Benton enters.)
BENTON: Excuse me, sir.
BRIGADIER: Well, where is he?
BENTON: I'm sorry, sir, but he just won't come.
BRIGADIER: Sergeant, I sent you to get Professor Stahlman.
BENTON: Well, that's just it, sir. Professor Stahlman won't come. He's says he's too busy to
BRIGADIER: Too busy to what, Sergeant?
BENTON: He says he's too busy to waste time bandying words with a pompous military idiot, sir!
BRIGADIER: Sergeant, I want to see Professor Stahlman and I want to see him now, and I advise you not to come back without him.
BENTON: Sir, if you
BRIGADIER: A chance to use your initiative, Sergeant!
BENTON: Sir!
BRIGADIER: Carry him in here if you have to, but get him!
BENTON: Sir!

Doctor's workshop]

(Liz is turning switches, looking at the empty space where the Tardis used to be, and sighing. The doors start rattling so she rummages through her handbag for a sonic screwdriver, checks to see who is out there, and opens them.
LIZ: Won't you come in, Mister Sutton?
SUTTON: Hello. Yes. How did you do that?
LIZ: With this.
(And closes the doors again.)
SUTTON: A useful little gadget, eh?
LIZ: One of the Doctor's inventions. He used to call it the door handle.
SUTTON: Nice bloke, the Doctor. I miss having him around the place.
LIZ: So do I. Is there anything I can do for you, Mister Sutton?
SUTTON: Er, well, it's, er, it's like this, I
LIZ: Yes?
SUTTON: Well, I found myself passing this place and
LIZ: So you thought you'd just take a look?
SUTTON: Well, yes, I thought I might get a look at that wonderful machine the Doctor was supposed to be working on.
LIZ: Well, as you can see, there's nothing here.
SUTTON: He took it away with him, did he?
LIZ: That's right.
SUTTON: Do you know, it's a funny thing now.
LIZ: What is?
SUTTON: Well, I've been asking round, and nobody actually saw him go.
LIZ: Didn't they?
SUTTON: Well, that banger he uses is not exactly inconspicuous, and he didn't say goodbye to anyone.
LIZ: He didn't have very much time. He left in rather a hurry.
SUTTON: Well, since there's nothing here now, what are you still hanging around for?
LIZ: I don't know, I suppose I'm half-hoping he'll suddenly come back.
SUTTON: Just like that?
LIZ: He's very unpredictable.
SUTTON: I thought, possibly, the poor old Doctor had blown himself to smithereens and you were trying to hush it up.
LIZ: Yes, well, there was a sort of an accident.
SUTTON: Well, there's no sign of an explosion.
LIZ: No, no, not an explosion exactly, he
SUTTON: Well, this is a great place for disappearances, isn't it?
LIZ: How do you mean?
SUTTON: Haven't you heard? I gather Sir Keith Gold's vanished too.

[Brigadier's office]

STAHLMAN: This time, Brigadier, you've really gone too far. I'm literally dragged from my work by one of your ape-like minions.
BRIGADIER: He was acting on my orders.
STAHLMAN: By what possible right can you
BRIGADIER: Professor Stahlman, I have made innumerable attempts to secure a few moments of your valuable time. You've left me no choice.
STAHLMAN: Oh, very well. I suppose I'd better humour you. What is it you want?
BRIGADIER: Sir Keith Gold has disappeared.
STAHLMAN: Has he? I thought he was in London pouring out his petty complaints to the Minister.
BRIGADIER: He left the Minister yesterday evening. He should have been back here by last night.
STAHLMAN: Well, an accident perhaps?
BRIGADIER: There's been no report of any accident on any possible route from here to London.
STAHLMAN: Well then, I imagine he's had his complaints dismissed and has taken himself off in a fit of pique. It doesn't matter. We shall do very well without him.
BRIGADIER: I've tried to contact the Minister but he isn't available. Therefore, in view of Sir Keith's anxieties about this
STAHLMAN: Sir Keith is an old woman.
BRIGADIER: I must formally request that you delay Penetration Zero until his return.
STAHLMAN: On no account, Brigadier. This project will be carried through on schedule. My schedule. When that drill penetrates the Earth's crust, you'll see that my theories were correct.

[Central Control]

(But in the alternate reality, Greg is still holding back the Greens.)
GREG: Time's running out, Doc.
DOCTOR: That's it. I only hope it works. Shall we go, Mister Sutton?
GREG: I thought you'd never ask.
(Greg uses the coolant to herd the Greens back to the passage towards the drill head.)
GREG: Right you are, Doctor!
(The Doctor runs across the room and grabs two extinguishers from the wall.)
DOCTOR: Hurry along, my dear fellow. Hurry along!
(Greg puts the coolant pipe on the floor, takes an extinguisher from the Doctor and they leave. Green Stahlman stands up and follows.)

[Outside Central Control]

WILLIAMS: There they are!

[Nuclear Reactor Switch Room]

(The Doctor drives everyone there in Bessie.)
STEWART: I'll check the inner corridor.
DOCTOR: Now, Mister Sutton and I had better start work on the power connection. Will you be long, Doctor Williams?
WILLIAMS: I have to re-route the entire electrical system before I can boost the power.
DOCTOR: Be as quick as you can.
SHAW: What about the Brigade Leader and me?
DOCTOR: Well, you'd better wait here.
SHAW: Isn't there anything we can do?
DOCTOR: No, I'm afraid not. Now, I'll need some tools and a length of heavy duty cable.
GREG: We can pick that up at the rigger's stores. You'll pass it on the way to the hut.
DOCTOR: Right, come on, let's get on with it.
(The whole place shakes.)
SHAW: What's happening?
GREG: It's an earthquake!
WILLIAMS: It's getting nearer!
GREG: Yes, we're sitting on a powder keg!
DOCTOR: Right, come on!
STEWART: Get a move on!
(The Doctor and Greg take an extinguisher and drive off in Bessie. Meanwhile, a Green steps out of Central Control into the open air.) 
SHAW: I wonder if those creatures are moving out yet?
STEWART: Quite possible.
WILLIAMS: It's getting warm enough for them.
STEWART: How long is all this going to take?
WILLIAMS: I don't know.
STEWART: Well, can't you hurry it up, Doctor Williams?
WILLIAMS: No, not if I'm to do the job properly.
STEWART: You must! We've very little time!
WILLIAMS: Brigade Leader, I'm trying very hard to carry out a complex scientific task under impossible conditions. You will not help matters by bullying me.
STEWART: You are insolent, Doctor Williams.
WILLIAMS: Am I? Then it's about time that you learned that some problems just can't be solved by brute force and terror.
SHAW: Better let her get on with it, Leader. We're in her hands.
STEWART: We've got to the power through to the hut. It's our only chance.
SHAW: But the Doctor said he can't take us with him.
STEWART: Do you think he wants to help us? He's only concerned with his own safety.
SHAW: I think he's telling the truth. I think he has been all along.
STEWART: When the time comes, he will take us. He'll have no choice.
(One by one the Greens step out in to the 'cold' outside air.)

Doctor's workshop]

(Greg brings over the end of the cable.)
GREG: So that's the contraption, is it?
DOCTOR: The console, Mister Sutton, the console.
GREG: Well, I thought it'd be a bit more impressive than that.
DOCTOR: What did you expect? Some kind of space rocket with Batman at the controls?
GREG: And this brought you all the way here, did it?
DOCTOR: Er, well, it wasn't exactly a journey in the accepted sense of the word. It sort of slipped me sideways into your dimension.
GREG: Will it take you back?
DOCTOR: Theoretically, yes.
GREG: Well, is it all right?
DOCTOR: I hope so. Now fix the connector to the cable, will you?
GREG: Right. I hate to tell you, but if we put the entire output of the nuclear reactor through this, it'll blow in the first few seconds.
DOCTOR: A few seconds are all I need, Mister Sutton.

[Nuclear Reactor Switch Room]

STEWART: Are you making any progress?
WILLIAMS: I'm worried about the relay circuits. They're not functioning properly. I'm trying to rig up a bypass.
SHAW: Could the reactor have packed up?
WILLIAMS: No, it's still working, but it could go at any moment.
STEWART: Yes, we're well aware of that, Doctor Williams. You must hurry!
WILLIAMS: As I've already told you, Brigade Leader, I'm hurrying as fast as I can.
(Another quake.)
SHAW: All right, Brigade Leader, we're still here.
STEWART: I don't like your tone. Those explosions are getting closer. I'm thinking about the safety of all of us.
SHAW: Oh, yes, yes, of course you are.
STEWART: We've all got to get out of here!
WILLIAMS: You go if you want to. I shall stay here and finish the work.
STEWART: You carry on with your work!
SHAW: Where's there to go?
STEWART: If that spacecraft of the Doctor's works, you'll see for yourself.
SHAW: You don't really think you can force him to take us? He's not the sort of man you can frighten.
STEWART: Once that thing's working, we can take it over.
SHAW: We don't know how to operate it.
(BOOM!)
STEWART: Doctor Williams can learn how to operate it. She's a scientist!
SHAW: That device is beyond all our comprehension.
STEWART: Then I shall have to persuade him to operate it for us.
SHAW: And if he tries to go by himself?
STEWART: And leaves us to die? I shall make sure that he dies first.

Doctor's workshop]

(The Doctor is working underneath the console.)
GREG: If we get you back, Doctor, you'd better make darn sure they stop their drilling. I'd hate to think all this was for nothing.
DOCTOR: Right. You can connect up the cable now.
GREG: Right. And cross our fingers and trust to luck.
DOCTOR: We're not relying on luck, Mister Sutton, but skill.

[Nuclear Reactor Switch Room]

SHAW: Finished?
WILLIAMS: I think so. I just have to switch on and pre-set the power controls.
SHAW: How do we know the Doctor's ready for the power?
WILLIAMS: Oh, it doesn't matter. The power won't flow until he switches on at his end.
STEWART: And then we may all go up in smoke?
WILLIAMS: No, I've switched off all other circuits.
SHAW: Good luck.
(Williams pulls the power lever down into the red.)
STEWART: Well? What's happened?
WILLIAMS: Nothing.
SHAW: There must still be a fault.
STEWART: So, you've been wasting our time.
SHAW: Try again.
WILLIAMS: It's no use! I'll have to go through the whole wiring system all over again!

Doctor's workshop]

GREG: What's happened to them? They should be back here by now.
DOCTOR: You must try and be patient.
GREG: If those explosions reach the nuclear reactor.
DOCTOR: Yes, I know.

[Nuclear Reactor Switch Room]

STEWART: That's coming from the drill-head!
SHAW: The shaft must be splitting open!
STEWART: Well
(Stahlman has come in through the inner door.)
STEWART: Get out! Get out both of you!
(The women run. Brigade Leader shoots at Stahlman then follows. Outside, they all keep falling over as the ground shakes, whilst they run from Benton and another Green.)

Doctor's workshop]

GREG: No sign of them. Nothing!
DOCTOR: Well, that appears to be that. I doubt whether they would have listened to me anyway.
GREG: They're coming! All three of them! Well done, Petra! Are you ready, Doctor?
DOCTOR: What's the matter?
WILLIAMS: I'm sorry. I couldn't get the power through. I did all I could.
DOCTOR: Yes, of course you did, my dear.
GREG: Well, we tried, eh, Doctor?
DOCTOR: One can't do more than that, Mister Sutton.
STEWART: Oh, very philosophical, Doctor. Thank you very much, I knew you tried. All very cosy.
DOCTOR: Hysteria won't help us, Brigade Leader.
STEWART: Nothing will help us. That bore's going to blast any minute and we'll all be roasted alive.
GREG: Look what's happening to our hard man. You were all very tough when you were backed up by a bunch of thugs. How do you like it on your own?
STEWART: I warn you
GREG: You warn me? That's a laugh. You're finished, Brigade Leader. Finished!
STEWART: I can still deal with you, Sutton!
(Stewart jabs his pistol into Greg's stomach.)
GREG: With that? Even if you had the guts, you'd only be doing me a favour.
(Click. The Brigade Leader is out of bullets.)
GREG: What do you do now, slap my wrists?
STEWART: I don't need a gun to finish you!
(Stewart grabs Greg round the throat but is easily pushed off and thumped in the gut. Greg punches the Brigade Leader around the hut.)
DOCTOR: Listen to that! Do you want to end your lives fighting like animals?
GREG: Where's Petra?
SHAW: She's gone back to the main switch room to have another try at getting the power through.
GREG: Oh, the idiot! I'd better get after her.
DOCTOR: I'll come with you.
GREG: No, Doctor! You stay here. She might just manage it, and if she does, you need to be here.

[Nuclear Reactor Switch Room]

(Williams is working at the control panel while Stahlman lies on the floor.)
GREG: What do you think you're doing?
WILLIAMS: I'd nearly finished the rewiring when we had to run out of here. I only need a few more minutes.
GREG: It was crazy to come back in here.
WILLIAMS: It doesn't matter. He's dead.
GREG: Well, he may not have been. What are you trying to do, commit suicide?
WILLIAMS: What does it matter? We're nearly finished anyway.
GREG: All right but get a move on!
(As Greg watches the door, Stahlman gets up and snarls at Williams. Greg runs over, snatches up an extinguisher and uses it on him.)
GREG: Are you all right?
WILLIAMS: I think so. That should do it.
(Four red lights start blinking.)
WILLIAMS: It's working!
GREG: All right, let's get back to the hut.

Doctor's workshop]

(The Tardis console time rotor starts going up and down.)
SHAW: The power's coming through!
DOCTOR: It's coming through all right, and it's gaining rapidly.
SHAW: Hurry, Doctor!
DOCTOR: Well done, Doctor Williams!
WILLIAMS: Quickly, Doctor. The power won't last for long.
STEWART: Long enough. You're going to take us with you, Doctor.
DOCTOR: I can't. It's impossible.
STEWART: I advise you to try.
DOCTOR: I can't. I literally can't! It'd create a cosmic disaster.
STEWART: You're not going to leave us here!
DOCTOR: Do you think I want to? I'd give anything to save you all.
GREG: It's not loaded!
(Stewart fires a shot in the air. Oh yes it is.)
SHAW: Let him go, Brigade Leader.
STEWART: We helped him. we've every right to go. I'll give you until three, Doctor. One
DOCTOR: You'll have to shoot me, Brigade Leader. I have no intention of taking you.
STEWART: Two. Three
(Stewart fall, shot.)
SHAW: Now's your chance, Doctor!
GREG: Go on, Doctor. Get on with it!
(The complex explodes like a Thunderbirds disaster, and a volcano erupts. People try to flee from the lava flow.)
SHAW: Go on, Doctor! Go now!
DOCTOR: I can't! It's still too erratic!
WILLIAMS: Greg!
(A stream of lava is flowing towards the open doors of the hut.)

Episode Seven

Doctor's workshop]

(The Doctor is lying on the floor. He is clearly back in the correct reality because the shelves are a jumbled mess of books. Liz opens the doors with her sonic screwdriver and enters.)
LIZ: Doctor!
(Liz calls out across the complex.)
LIZ: Sergeant! Over here, quickly!
BENTON: What's the matter? It's the Doctor!
LIZ: I can see that. Tell the Brigadier.
BENTON: Right, Miss Shaw.

[Central Control]

(The clock reads 3:22:38 and counting.)
STAHLMAN: It's perfectly straightforward, Petra. We boost all power circuits to maximum load and that'll give us a further acceleration of three point six percent. Well, do you find some fault in my calculations?
PETRA: Of course not, Professor Stahlman.
STAHLMAN: Well then, what's the matter?
PETRA: We're already twelve percent over the planned acceleration. Well, another three percent'll take us well over the safety margin.
STAHLMAN: Safety margins are for cautious old women like Sir Keith. I know perfectly well what I'm doing. Pass on my instructions please.
(Stahlman leaves.)
SUTTON: You look worried.
PETRA: He's ordered a further acceleration. Three point six percent.
SUTTON: But he can't do that!
PETRA: I'm afraid he can.
SUTTON: We're pushing the safety limits now.
PETRA: Yes, I know.
SUTTON: I'm going to have a word with him.
PETRA: Greg, it's no use. He usually listens to me, but this time
SUTTON: But not any more, eh? Let's face it, Petra, he's losing his grip.
PETRA: Professor Stahlman's been working on this project for years. He must know what's going on.
SUTTON: But he can still make mistakes, can't he? If he makes one at this stage, it could be a lulu!
PETRA: Greg, let me talk to him first.
SUTTON: All right. You go and soften him up and I'll close in for the kill.
(Petra leaves. The Brigadier enters, followed by Benton.)
BENTON: Sir?
BRIGADIER: Well, Benton?
BENTON: Excuse me, sir, but it's the Doctor. He's, well, he's back.
BRIGADIER: Well, where is he?
BENTON: Well, he's in the hut, sir. Miss Shaw's with him.
BRIGADIER: Right, I'll come back with you now.
BENTON: Right, sir.

[Drill head]

STAHLMAN: My dear Miss Williams, much as I value your services, I must remind you that you're not in control of the
(Stahlman stops, staring at nothing.)
PETRA: Professor! Professor Stahlman! Are you all right? You look ill.
STAHLMAN: Yes, I have a headache, that's all.
PETRA: You really ought to go to the sickbay.
STAHLMAN: I'm perfectly all right.
(Sutton enters.)
SUTTON: Look, Professor Stahlman, this accelerated drilling. It just isn't on, you know.
STAHLMAN: Someone else is about to tell me how to run my own project.
SUTTON: Well, we should be slowing down at this stage, not forcing the pace.
STAHLMAN: The drilling will continue at the pace I decide.
SUTTON: Professor, you've been working on this project for years, right? What's the mad rush in the last few hours?
STAHLMAN: We must reach penetration zero at the earliest possible moment. Every second
(Stahlman stops again.)
SUTTON: Professor? Professor? You need a rest.
STAHLMAN: I don't want to discuss the matter any further. Please carry out my instructions at once.
(Stahlman leaves.)
SUTTON: I thought you were supposed to soften him up?
PETRA: He just wasn't listening. Greg, he's ill. He had some sort of attack!
SUTTON: Yes, I saw it. Let's face it this whole thing's getting too much for him. He's cracking up.

Doctor's workshop]

(The Doctor is lying on a camp bed as Liz checks his heart rate.)
LIZ: Heart's beating steadily.
BRIGADIER: Both of them?
LIZ: Yes.
BRIGADIER: Well, what's the matter with him?
LIZ: Some sort of coma.
BRIGADIER: How long before he comes out of it?
LIZ: Difficult to say. Could be a few hours, a few months.
BRIGADIER: Months?
LIZ: Some people never recover.
BRIGADIER: I'll send for a doctor.
LIZ: I happen to be a doctor, Brigadier, remember?
BRIGADIER: Shouldn't he be in hospital?
LIZ: I think it'd be very dangerous to move him at all.
BRIGADIER: What, leave him here?
LIZ: Why not? It's quiet. We can keep him warm.
BRIGADIER: Miss Shaw, I really think he needs medical attention.
LIZ: Brigadier, I will look after him.

[Central Control]

SUTTON: If you could spare me a moment, Professor? I've been checking an emergency flange on number two output pipe.
STAHLMAN: It was repaired some time ago.
SUTTON: Yes, well, the man didn't do a very good job and at the rate we're drilling, that flange could blow at any moment.
STAHLMAN: Then what do you suggest?
SUTTON: Well, if you could slow down the drilling rate, I can get a proper job done.
STAHLMAN: Another transparent excuse for delay.
SUTTON: Excuse, nothing! At the speed we're drilling, we could blow this place sky high before you ever reach penetration zero.
STAHLMAN: Mister Sutton, you're here on sufferance. That being the case, I suggest
SUTTON: I'm here because I was sent for by Sir Keith! And believe me, working with you is no pleasure.
STAHLMAN: Then I suggest you stop interfering in matters beyond your understanding.
SUTTON: I'm trying to help. I am supposed to be an advisor.
STAHLMAN: Yes, one of Sir Keith's little army of experts. Well, we don't need your advice, Mister Sutton. Now that ridiculous Doctor has gone, Sir Keith himself has gone, why don't you follow their example? And then we might make some progress.
SUTTON: Don't worry, I'll do just that. As far as I'm concerned you can blow yourself to kingdom come!
(Stahlman leaves.)
PETRA: Greg! You're not serious, are you?
SUTTON: Of course I'm serious. If I can't do anything else, at least I can save my own neck. Why don't you come with me?
PETRA: You're convinced there'll be a blow up?
SUTTON: I'd take odds on it well?
PETRA: I can't leave. You know that.
SUTTON: Loyal to the last, eh?
PETRA: I wish you'd change your mind about leaving.
SUTTON: Why?
PETRA: Well, if anything were to happen, I'd like to think you were here.
SUTTON: Just for the good of the project?
PETRA: No! Not entirely. I've just got used to your being around.
SUTTON: Maybe I haven't been wasting my time down here after all.
(An alarm goes off. Smoke and green ooze are pouring from the drill head.)

Doctor's workshop]

BRIGADIER: (into phone) Hello. Get me Control. Yes, I can hear the alarms. Now this is Brigadier Lethbridge Stewart. Now get me Control!
(The Doctor's face twitches.)
BRIGADIER: Hello, Control? Lethbridge Stewart here. Now, what's happening? Yes. Yes, yes, yes, go on! How serious?
(The Doctor groans. Eyes still closed, he starts talking.)
LIZ: Doctor?
DOCTOR: Number two. Number two output pipe blown.
LIZ: Doctor, can you hear me?
DOCTOR: Number two output pipe.
BRIGADIER: What did he say?
DOCTOR: Very dangerous. Very dangerous. Number two output pipe blown.
BRIGADIER: How on earth did he know?
LIZ: What?
BRIGADIER: The emergency flange on number two output pipe has blown. It's just this minute happened.
LIZ: Listen.
DOCTOR: There's only one thing, one thing to do. Reverse, reverse all systems. Reverse all systems immediately.
LIZ: Reverse all systems.
DOCTOR: Reverse all systems!
BRIGADIER: Delirious.
DOCTOR: Yes.
LIZ: He knew
about the leak, almost as though he expected it. 
BRIGADIER: But how could he? Look at him, he's still in a coma.
LIZ: Doctor, can you hear me? Doctor? Doctor?
BRIGADIER: It's no good.
LIZ: Keep an eye on him, Brigadier. I think Central Control ought to know about this.

[Central Control]

(Technicians are rushing about.)
STAHLMAN: Keep calm! This is only a minor emergency. It can be contained.
PETRA: Professor, stop the drill!
STAHLMAN: No, positively not.
SUTTON: You'd better do something, and quick, Professor, otherwise you'll bust this place wide open!
(Liz enters.)
STAHLMAN: Have those riggers arrived yet?
SUTTON: Look, an army of riggers are not going to get you out of this one!
STAHLMAN: Oh, get back there. Go on! Get back to your posts all of you! Back to the drill head. How dare you leave bank seven. (Stahlman chases a group of technicians back into the drill head.)
SUTTON: Look at him! He's out of his mind! He's not even trying to think of a solution!
PETRA: Is there one?
LIZ: What would happen if you reversed all the systems?
SUTTON: What?
LIZ: Reversed everything.
SUTTON: Well, it's not such a crazy idea. It's been done before.
PETRA: With an oil shaft?
SUTTON: Yes, in Arabia. You push all the coolant down the output pipes and draw up the debris from the bottom of the shaft in the input pipes.
LIZ: Reverse the vortex?
SUTTON: Yes.
LIZ: It's a possibility, theoretically.
PETRA: Professor Stahlman would never permit it!
LIZ: Just do it.
SUTTON: Why not? What about it, Petra?
PETRA: Come on!
(The Doctor continues to twitch while the alarm sounds, then relaxes as it shuts off.)
SUTTON: Well, I reckon it's working.
LIZ: Seems to be.
SUTTON: That was a brilliant idea of yours.
LIZ: Oh, it wasn't my idea.
SUTTON: Then who? No, don't tell me. The Doctor. I heard he was back.
LIZ: That's right, the Doctor.
(There is far less smoke coming out of the drill head.)
STAHLMAN: I gave no such orders.
PETRA: No, Professor Stahlman, I did.
STAHLMAN: Even you, Petra.

Doctor's workshop]

LIZ: Doctor, are you all right?
DOCTOR: (waking) Liz? It is Liz.
BRIGADIER: How are you, Doctor?
DOCTOR: Fine, Brigadier. You know, you really do look better with that moustache.
BRIGADIER: Delirious, poor chap.
LIZ: Doctor, you really ought to rest. You've been unconscious.
DOCTOR: Yes, I'm very well aware of that. Oh, the pulse seems to be more or less normal, at a hundred and seventy. Yeah. Yes, both ticking away quite nicely. Although the right one seems a fraction faster. Still that's only to be expected, isn't it?
LIZ: Doctor, where did you go? Where did the Tardis console take you?
DOCTOR: Same time, same place, only a different dimension. It was a parallel world, Liz. Terrible things are happening there. Terrible things. It wasn't this Earth, and yet it was. I didn't go backwards into the past, or forwards into the future. I slipped sideways.
LIZ: You must lie down.
DOCTOR: Brigade Leader, that technician, the one who went berserk and started killing people, have you found him yet?
BRIGADIER: No.
DOCTOR: And Stahlman, how's he?
LIZ: Still as difficult as ever.
DOCTOR: But no worse?
LIZ: Well, I haven't noticed.
DOCTOR: How's the drilling?
(Someone knocks at the door.)
LIZ: Just a minute.
(Liz opens the door.)
DOCTOR: Sir Keith!
(Gold has his left arm in a sling.)
GOLD: My dear fellow, so you've come back to us after all.
DOCTOR: So you're not dead?
(LIZ closes the doors.)
GOLD: No, I came very close to it though.
BRIGADIER: Why, what happened?
GOLD: Car crash.
DOCTOR: But you're not dead.
BRIGADIER: You can see he's not dead. The Doctor's been ill, sir.
DOCTOR: That's excellent! Excellent!
GOLD: Well, yes, yes, I think so too. Brigadier, I shall have to lay very serious charges against Professor Stahlman. He ordered my chauffeur to delay my return.
DOCTOR: So not everything runs parallel.
GOLD: He's been ill, you said?
BRIGADIER: Yes, a coma.
DOCTOR: Yes, of course, of course. An infinity of universes, ergo an infinite number of choices. So free will is not an illusion after all. The pattern can be changed.
BRIGADIER: (into phone) Hello, get me the medical section will you? Thank you.
DOCTOR: Now look.
BRIGADIER: Yes, very well.
DOCTOR: Now, wait a minute. I'm not sick, I'm not in need of a doctor and I'm not a raving idiot!
(The Doctor slams the phone down.)
BRIGADIER: No, no, no, of course not. Perhaps you've had some sort of nightmare.
LIZ: He did disappear. We saw him.
DOCTOR: Sir Keith, unless we do something very, very quickly indeed, there's going to be a disaster.
GOLD: How do you know, Doctor?
DOCTOR: Because I've already seen it.

[Central Control]

DOCTOR: Professor Stahlman? You must stop this drilling immediately!
STAHLMAN: Who let this maniac back in here?
DOCTOR: Do you hear me? Close down this operation now!
STAHLMAN: Brigadier, arrest this man.
DOCTOR: Now listen to me, all of you! You are not to attempt to penetrate the Earth's crust!
STAHLMAN: Brigadier, did you hear what I say?
BRIGADIER: Doctor, please?
DOCTOR: Get out of my light! Now stop this drilling!
(The Doctor attacks a console with a wrench.)
LIZ: Doctor!
DOCTOR: Stop this drilling! You don't understand, do you?
BRIGADIER: Benton, get some help, quickly!
DOCTOR: You've got stop this drilling!
SUTTON: Now Doctor, calm down!
STAHLMAN: You see? Completely demented.
DOCTOR: Stop this drilling!
(Soldiers grab the Doctor's arms.)
BRIGADIER: Take him to the sick bay. Be careful. I don't want him hurt.
LIZ: No, you can't!
DOCTOR: Now Liz, listen to me. Computer. There's a micro circuit missing.
LIZ: I'll look. Will you treat him carefully?
(The Doctor is hustled away.)
DOCTOR [OC]: Stop it! Stop this drilling!
STAHLMAN: Brigadier, I hold you responsible.
GOLD: Professor Stahlman, I'd like to speak to you please.
STAHLMAN: Ah, Sir Keith. I thought you were supposed to be in London. An accident?
GOLD: This is a direct consequence of your orders to my chauffeur.
STAHLMAN: Hmm? Huh! Ridiculous.
GOLD: Professor, the Minister would like you to report to him immediately, please.
STAHLMAN: Oh, he would, would he?
GOLD: There's to be an inquiry into this project and, if I may say so, into your conduct.
STAHLMAN: You can make as many inquiries as you like, my dear Gold, after we've penetrated the Earth's crust.

[Drill head]

PETRA: Professor Stahlman, I'll be switching to robot controls in forty nine minutes.
STAHLMAN: Thank you.
PETRA: Any wrong, Professor?
STAHLMAN: I feel very cold in here.
PETRA: Cold?
STAHLMAN: Yes. Have the maintenance people raise the temperature.
PETRA: But it's running normally.
STAHLMAN: Do as I say.
(Petra leaves. Stahlman tenses and stares at nothing, whilst hearing something. The technicians stare.)
STAHLMAN: All of you leave this area immediately! Go on! I shall control the last phase of this operation alone. Stand by in the drill head there. Now, go on! Get out, all of you. Go on. Do as I say.
(Once alone, he clutches his head in pain.)

[Central Control]

SUTTON: He's just ordered them all out of there. Now do you believe he's cracked up?
PETRA: Greg, the heat shield!
(The shield slides down to close off the drill head.)

[Research complex]

DOCTOR: Well, I'm sorry about this, gentlemen.
(The Doctor grabs the back of the necks of his two escorts. They collapse, he runs, then heads up a ladder, only to find Green Bromley on the top of the storage tank too. The Doctor grabs a CO2 fire extinguisher and uses it.)

[Central Control]

(Green ooze is coming out of number two output pipe. Stahlman puts his green, hairy hand into it then smears it on his face before falling to the floor growling like an animal. His voice comes over the comms.)
PETRA: Professor Stahlman! Please! What's happening? What's going on in there?
GOLD: Why don't you raise the heat shield?
SUTTON: Because he's locked it down on manual from the inside.
(Stahlman now has a full hairy face and fangs.)

[Central Control]

(Liz has mended the computer and is reading the printout.)
SUTTON: What does the thing say now?
COMPUTER: Zero minus two minutes, fifty seconds.
LIZ: The Doctor's right. It advises us to stop the drilling at once.
COMPUTER: Robot control now operational.
SUTTON: Why don't you give the order, Sir Keith?
GOLD: Oh, I can't. The order to close down must come from the Professor. I have no authority to intervene.
COMPUTER: Zero minus two minutes, forty seconds
(The Doctor enters.)
DOCTOR: Where's Stahlman?
LIZ: He's locked himself in there!
COMPUTER: To final build up. 
DOCTOR: Good. Then stop this infernal drilling. Well, what are you waiting for?! 
COMPUTER: Zero minus two minutes, thirty seconds
DOCTOR: Stop this drilling and start filling up that shaft!
GOLD: The data from the computer isn't conclusive, Doctor, nor is Stahlman's behaviour. We have no proof of an emergency situation.
(The heat shield rises.)
COMPUTER: Zero minus two minutes, twenty seconds. Heat control shields now on stand by.
(Green Stahlman rushes in.)
MAN: Zero minus two minutes ten seconds.
DOCTOR: Stahlman, get back! Sutton, the fire extinguishers!
(As the Doctor turns to get an extinguisher, Green Stahlman raises a chair to hit him. The Brigadier shoots.)
DOCTOR: Fire extinguishers!
(The Doctor and Sutton use the CO2 on Green Stahlman.)
COMPUTER: Zero minus two minutes, zero seconds and counting. Condition red three now commences.
(Green Stahlman collapses.)
BRIGADIER: That's Stahlman?
GOLD: What's happened to him?
DOCTOR: Petra, the drill. Close it down.
COMPUTER: Zero minus one minute fifty seconds.
GOLD: Cut off the nuclear power.
PETRA: But the drill will disintegrate!
SUTTON: All the better!
COMPUTER: Monitoring circuits.
PETRA: Prepare for emergency shutdown!
TECH 1: Section one standing by.
COMPUTER: Zero minus one minute
TECH 2: Section two standing by.
TECH 3: Section three standing by.
DOCTOR: Hurry, hurry!
PETRA: Shut down, now!
TECH 1: Section one shut down.
COMPUTER: Zero minus one minute, thirty seconds.
TECH 2: Section two shut down.
COMPUTER: Power build up now completed.
TECH 3: Section three shut down. Shut down completed.
BRIGADIER: But it's still going on!
COMPUTER: Zero minus one minute, twenty seconds.
DOCTOR: That's the buffer controls at the drill head. Come on!
COMPUTER: Non-technical staff to safety positions.
BRIGADIER: Buffer controls?
GOLD: Oh, they it slow down by stages. It'll keep going for at least five minutes.

[Drill head]

(A wall panel is open and wires are hanging out.)
COMPUTER: Zero minus one minute, ten seconds.
SUTTON: The server switches are smashed!
COMPUTER: All systems check for final countdown.
SUTTON: Is there anything you can do?
DOCTOR: I can only try.

[Central Control]

COMPUTER: Zero minus one minute, zero seconds and counting. Final countdown commences now.

[Drill head]

(The Doctor works on putting the wires back together.)
COMPUTER: Zero minus

[Central Control]

COMPUTER: Fifty seconds. Stand by.
(The Doctor and Sutton enter.)
COMPUTER: Attention, attention. Countdown drilling stopped at minus thirty five seconds. All systems closed down.
(Liz hugs the Doctor as Petra hugs Sutton.)
DOCTOR: Sir Keith, I think you'd better give orders for that shaft to be filled in straight away.
GOLD: Indeed, I will.
BRIGADIER: I'll send for a stretcher party.

Doctor's workshop]

(The Doctor is singing his version of Shine On Harvest Moon.)
DOCTOR: Shine on Martian moons, up in the sky. Join in. Liz, come on.
(Someone knocks on the door. Liz goes to let them in.)
DOCTOR: Shine on, shine on, Martian moon.
GOLD: Sorry to disturb you, Doctor. I just popped in to say goodbye.
DOCTOR: Oh, are you leaving, Sir Keith?
GOLD: Everyone is.
BRIGADIER: Word came through this morning. This project is being officially abandoned.
DOCTOR: Well, I'm not sorry to hear that. What about the nuclear reactor?
GOLD: They're dismantling it tomorrow.
DOCTOR: Oh, but there's time for me to use it just once more, I hope?
GOLD: Oh, yes, of course, with pleasure. It's the least we can do.
DOCTOR: Thank you, Sir Keith. By the way, how's Sutton and Miss Williams?
GOLD: Oh, they've left already.
LIZ: Together?
GOLD: Well, I believe he is driving her to London in his car.
DOCTOR: Nothing like a nice happy ending, is there?
GOLD: No. Well, goodbye, Doctor.
DOCTOR: Goodbye, Sir Keith.
GOLD: Goodbye, Miss Shaw.
LIZ: Bye bye, Sir Keith.
DOCTOR: Goodbye, Brigadier.
BRIGADIER: Oh, there's quite a lot of mopping up to do. I shall be around for quite a while yet.
(Gold leaves.)
DOCTOR: Oh, pity. Well, come on, Liz. If we've going to link up to that nuclear reactor, we'd better get a move on.
LIZ: Now, just a moment, Doctor.
BRIGADIER: Doctor, you're not still tinkering with this machine after all the trouble it's caused us?
DOCTOR: The trouble it's caused you?
BRIGADIER: Doctor, if you hadn't chosen such a crucial moment to disappear, this whole business might have been cleared up a great deal sooner.
LIZ: Well, he did try to warn everybody, Brigadier.
DOCTOR: And a fat lot of notice you all took.
BRIGADIER: So, you went gallivanting off in a fit of pique.
DOCTOR: Brigadier, there are times when you strongly remind me of your other self. I shall leave at once.
LIZ: In the Tardis console?
DOCTOR: Naturally.
LIZ: Oh, but Doctor, you can't.
(The Doctor throws the main power breakers.)
DOCTOR: With the work that we did today, the Tardis console is now fully operational.
BRIGADIER: We seem to have heard that before.
DOCTOR: Goodbye, Liz. I shall miss you, my dear. But I've had about all I can stand of this pompous, self-opinionated idiot here.
(The Doctor and the console vanish.)
LIZ: Now see what you've done.
BRIGADIER: Well, I didn't know he'd go off like that. The man's so infernally touchy.
LIZ: Well, I shall be most interested to see how you get on without him, Brigadier.
BRIGADIER: May I remind you, Miss Shaw, that you're still a serving member of UNIT? I don't entirely care for your tone.
LIZ: I don't much care for yours either. No wonder the Doctor cleared off.
(There is an cough from the open doorway. There are stains on the Doctor's jacket.)
BRIGADIER: Welcome back.
LIZ: Where did you go?
DOCTOR: A few seconds forward in time, and a few hundred yards due east in space.
LIZ: The rubbish tip?
DOCTOR: The rubbish tip.
LIZ: Oh, dear.
DOCTOR: Er, Brigadier, my dear fellow, I wonder whether I could borrow a couple of your stalwart chaps to give me a hand in bringing the Tardis back? It's landed in rather an inaccessible position.
BRIGADIER: Pompous, self-opinionated idiot, I believe you said, Doctor?
DOCTOR: Yes, well we don't want to bear a grudge for a few hasty words, do we? No, not after all the years that we've worked together. Now come long, my dear fellow, put on a smile. Just remember all
(Liz laughs as the Doctor leads the Brigadier out.)