Part One

(A wheel and spoke design space station hangs in orbit above Earth. It has a space shuttle sitting next to the spoke. We go inside and see it through the green-tinted sight of something that probably shouldn't be there. There appear to be people encased in plastic pods. The lid of a pod opens to reveal a young man dressed in white, then we leave.)

[Secondary control]

(The TARDIS materialises inside a dark room. The Doctor emerges carrying a torch.)

DOCTOR: You're a clumsy, ham fisted idiot.
HARRY [OC]: I said I was sorry, didn't I?
DOCTOR: What? Come out! (thud) And don't touch anything.
HARRY [OC]: I'm only trying to open the door.

(Harry comes out of the TARDIS.)

HARRY: Oh, I say. We've gone!
SARAH: Who's gone?

(Sarah comes out of the TARDIS carrying an oil lamp.)

HARRY: I mean, this isn't. We aren't where we were when. I've gone mad.
SARAH: That's how I felt the first time. Where are we, Doctor?
DOCTOR: I've no idea.
SARAH: A little trip to the moon, you said, just to prove to Harry
DOCTOR: I didn't expect him to start messing about with the helmic regulator. Come away from there, Harry.
HARRY: You could sell that thing, Doctor.
DOCTOR: I could what?
HARRY: Jolly useful in Trafalgar Square. I mean, hundreds of bobbies hiding inside it.
SARAH: Harry.
HARRY: Eh?
SARAH: Stop burbling.
HARRY: What? Oh, sorry. Shock, I suppose. I must say, I feel very strange.
DOCTOR: Not much oxygen. Still, nothing to worry about.
SARAH: Suffocation is nothing to worry about?
DOCTOR: We can survive for quite a time yet.
SARAH: While you play with that yo-yo?
DOCTOR: Just a simply gravity reading, Sarah. Yes, almost certainly we're in some kind of artificial satellite. Now isn't that interesting?
SARAH: Not very.
DOCTOR: I think it is.
SARAH: It's dark, it's cold and it's getting very airless.
DOCTOR: All we have to do is get the power back on. Let's see what's over here.
SARAH: Might as well go for a look round, I suppose. Are you coming?
HARRY: We'd better stick with the Doctor, don't you think?

(The Doctor finds the light switch. The decor is futuristic white with some control panels in the wall and a couple of desks and chairs.)

DOCTOR: Yes! That's better. Incredible.

(Sarah blows out her lamp.)

HARRY: I say. What's all that for?
DOCTOR: I've never seen anything quite like it.

(A door slides open next to Sarah.)

SARAH: Hey, Doctor.
DOCTOR: Definitely build on Earth, but I can't quite place the period.

(The next room contains even more equipment.)

SARAH [OC]: Doctor, look!
DOCTOR: In a minute, Sarah!
SARAH [OC]: But
HARRY: None of it seems to work now, anyway.

(Sarah enters the new room, which contains a couch on a slight incline, and examines a large console sticking out of the wall. She does not notice that the door has silently closed behind her.)

DOCTOR: Judging by the macro-slave drive and that modified version of the Bennett oscillator, I'd say this was built in the early thirtieth Century?
HARRY: (gasping) Oh, no.
DOCTOR: You don't agree?
HARRY: Early thirtieth century?
DOCTOR: Late twenty ninth, early thirtieth, I feel sure.

[Control room]

(Sarah is also finding breathing getting difficult. Then she discovers the closed door.)

SARAH: Doctor! Doctor! There's hardly any air in here! Doctor, please!

(Sarah hammers at the door.)

[Secondary control]

(There is no sound of Sarah's thumping in here.)

HARRY: Doctor, I'm a simple sort of chap. Are you trying to tell me we're now in the middle of the thirtieth century?
DOCTOR: Good heavens, no. Well beyond that.
HARRY: Beyond the thirtieth?
DOCTOR: Well, you gave that helmic regulator quite a twist, I'm afraid.
HARRY: Where are we?
DOCTOR: It's difficult to say. All this stuff's obviously been here for some time. Several thousand years at least. What was that?

[Control room]

SARAH: Doctor, I can't breathe

[Secondary control]

DOCTOR: Sarah? Where's she got to?
HARRY: In the TARDIS?
DOCTOR: Impossible, I've got the key. I've told her time an again about going off by herself. Sarah?
HARRY: Well, there's only one door and she. I swear she didn't go out that way.
DOCTOR: There must be another exit, then.
HARRY: A sort of hidden deck hatch or something?
DOCTOR: Vacuum-tight panel, more likely. They used them a lot in these early space vessels. Ah. Just as I thought.
HARRY: No doorknob.
DOCTOR: There must be a remote control. You haven't touched anything have you, Harry?
HARRY: Me?
DOCTOR: Well, there are only two of us here and your name is Harry.
HARRY: Oh, yeah. I did just touch one switch.
DOCTOR: Which switch, Harry?
HARRY: Nothing happened.
DOCTOR: Which switch?
HARRY: Which switch? Well, I think it was. Well, no, no, perhaps it was. I may have been standing
DOCTOR: Try to remember, Harry.
HARRY: I am trying! It's awfully difficult. I can hardly breathe.
DOCTOR: Think where you were standing.
HARRY: Er, it was this one.
DOCTOR: Sure?
HARRY: But nothing happened.
DOCTOR: Go on, press it.

(The door opens.)

[Control room]

(Sarah has passed out.)

HARRY: Crikey, she's cyanosed.
DOCTOR: No air in here. Help me to get her back.
HARRY: Quick.

(But the door closes as they pick up Sarah.)

HARRY: Now what'll we do?
DOCTOR: There must be a reverse mechanism.
HARRY: I've always hated sliding doors, ever since I caught my nose in one in Pompey Barracks.
DOCTOR: How is she, Harry?
HARRY: She'll be okay if we can get her out of here.

(The Doctor tries various switches on the big console.)

DOCTOR: Must be a broken circuit.
HARRY: What?
DOCTOR: Nothing. Nothing's working properly here.
HARRY: Oh?
DOCTOR: I've found the oxygen supply.
HARRY: Well done.

(The Doctor turns a knob underneath a nozzle high in the wall.)

DOCTOR: No good, Harry.
HARRY: No luck, eh?
DOCTOR: Why is nothing functioning here?
HARRY: Couldn't we smash our way out or something?
DOCTOR: What, with our bare hands?
HARRY: It's all my fault.
DOCTOR: I got us into this, Harry.
HARRY: I haven't got enough puff to argue with you.
DOCTOR: Then lie down and conserve the oxygen, while I do what I can. That's odd.
HARRY: What?
DOCTOR: These cables have been sheared clean through. Oxygen valve servo-mechanism. Yellow, black, green.

(He traces the cables back to the control panel.)

DOCTOR: Yellow, black, green. Yellow, black, green.

(He returns to the severed cables in the wall panel and uses his sonic screwdriver. The lack of oxygen starts to get to the Doctor, too, and he drops it. Finally he succeeds in getting fresh air rushing in.)

DOCTOR: Harry. Harry?
HARRY: Is she, she okay?
DOCTOR: Just in time. Are you feeling better?
HARRY: Convalescent. All I need now is a couple of weeks at the seaside.
DOCTOR: Good. Give me a hand to lay her on that couch. It's nearer the vents.
HARRY: Good thinking.

(They lay Sarah on the sloping couch and the Doctor opens up more nozzles.)

DOCTOR: I'll just repair some of those cables.
HARRY: Sheared, you said.
DOCTOR: Or bitten.
HARRY: What?
DOCTOR: There's a mystery here, Harry. Something happened a long time ago.
HARRY: Bitten?
DOCTOR: It looks like it. The interesting question is why? Clearly deliberate, therefore done for a purpose. Therefore, whatever it was had a reasoning intelligence.
HARRY: And very large teeth.
DOCTOR: Splendid! Now let's see if that panel works.

(The Doctor goes to the large console and presses a button. The door to the control room slides open.)

DOCTOR: All systems go, wouldn't you say?
HARRY: She's coming round.
DOCTOR: Good.
HARRY: Steady. Steady on, old girl. Steady on.
SARAH: Harry
HARRY: Yes, I'm here, I'm here.
SARAH: Call me old girl again and I'll spit in your eye.
DOCTOR: Welcome back, Sarah Jane.
SARAH: Couldn't breathe
HARRY: A drop of brandy'd be the thing now.
DOCTOR: There's some in the TARDIS.
HARRY: You'll be as right as ninepence in a minute. We're going to get you some brandy, all right?
SARAH: Ugh, I hate brandy.
HARRY: Doctor, do you think you could possibly persuade her to take some?

[Secondary control]

(A saucer-like infra red light fitting comes down from the ceiling.)

HARRY: I say, what's that?
DOCTOR: Get down, Harry?

(The Doctor pushes Harry down behind a desk. Harry leaves a shoe behind which gets zapped by the light.)

HARRY: Crikey. What is it?
DOCTOR: Keep your head down.

[Control room]

SARAH: Doctor?

(Lights flash behind the couch, and there is a soft humming sound. Sarah lies back on the couch and vanishes.)

[Secondary control]

(The Doctor holds his hat up on an extending aerial. It gets zapped.)

DOCTOR: We seem to be trapped, Harry.
HARRY: What is it?
DOCTOR: Some sort of automatic guard. I hadn't bargained on this when I repaired the circuits. I wonder. Of course! That's why they were cut in the first place.
HARRY: What about Sarah? If she comes out
DOCTOR: Tell her to stay where she is.
HARRY: Sarah? Sarah,

[Control room]

HARRY [OC]: Can you hear me, old girl? Keep away from the door. Do you understand? Keep away from the door!

[Tranquiller room]

(Sarah wakes in another room where soothing music is playing. She is lying in an alcove above a large console.)

SARAH: Where am I?
MAN [OC]: Welcome, sister. Welcome to Nerva. No, do not move. It is dangerous to move from the tranquiller couch. Please remain in contact with the biocryonic vibrations. In five minutes, the final phase of your processing must commence. If you have any personal possessions that you wish to have preserved, please place them in the casket adjacent to your right hand. Shortly you will hear the recorded voice of the High Minister speaking personally to you. At the conclusion of the Minister's message, there will be a two minute interregnum preceding the commencement of irradiation.

[Secondary control]

(The aerial is put up above the desk. Nothing happens.)

DOCTOR: Apparently it's not activated by movement unless what moves is organic.
HARRY: Hardly helps us, does it? We're organic.
DOCTOR: Not down here we're not, Harry.
HARRY: Oh, yes. Good piece of logical deduction, Doctor.
DOCTOR: Thank you.

(The Doctor begins to unscrew the desk from the floor.)

[Tranquiller room]

WOMAN [OC]: Greetings, Citizen Volunteer. This is the High Minister speaking on behalf of the World Executive. I salute you who are about to make the supreme sacrifice. In a few minute, you will pass beyond life. In case there is any fear in your heart and doubt in your mind at this awesome moment, let me remind you that you take with you all our past. You carry the torch that has been handed down from generation to generation.
SARAH: What's happening?

[Secondary control]

(The desk is moving across the floor.)

HARRY: Where are we going with it?
DOCTOR: To the far wall.
HARRY: Right.
DOCTOR: Inch it round your end.
HARRY: Okay.
DOCTOR: One slip, Harry, and we'll be charcoal. Push on.
HARRY: Right.

(Keeping the solid side of the desk towards the light fitting, they edge around the room to the control panels, landing up next to the other desk.)

DOCTOR: Psst, there it is.
HARRY: What?
DOCTOR: The trouble is, we can't reach it from here.
HARRY: What can't we reach?
DOCTOR: The auto-guard cut-out. Look, up there, see? Never mind. Faithful old scarf.

(The Doctor throws his scarf up towards the lever, but it gets zapped.)

HARRY: Bad luck. Jolly good try, though.
DOCTOR: It isn't a game of cricket, Harry.
HARRY: Sorry. Mind you, if I had a cricket ball, I'd jolly soon knock that switch.
DOCTOR: Will this do?

(The Doctor takes a cricket ball from his pocket.)

HARRY: Watch this, then.

(Harry polishes the ball on his jacket and throws it. Zap! It comes back down in pieces.)

HARRY: Organic, of course.
DOCTOR: Afraid so.
HARRY: Now what?
DOCTOR: There's only one thing left. Risky, but it might work. You don't want your other shoe, do you?
HARRY: I suppose not.
DOCTOR: Slip it off. Right. Now, I want you to throw it across the room. When I give the word, understand?
HARRY: All right.
DOCTOR: I'm going to try to distract it. Let's hope it's not double-barrelled. Ready?
HARRY: Ready.
DOCTOR: Now!

(Harry throws the shoe towards the light fitting and we hear the zap. At the same time, the Doctor leaps up and pulls the lever down. The light fitting glides back up into the ceiling.)

DOCTOR: I think we've done it, Harry.

(They stand up.)

DOCTOR: Pity about the scarf. Madame Nostradamus made it for me. A witty little knitter. All right, Sarah, you can come out now. Never get another one like it.
HARRY: Look at my shoes.
DOCTOR: Sarah?

(A door closes off Sarah's alcove in the tranquiller room and a heavy gas enters.)

[Control room]

(The Doctor opens up the couch to reveal a mass of circuitry.)

DOCTOR: What a fool. Of course!
HARRY: What is it?
DOCTOR: Why didn't I realise? Short range matter transmitter. The strange thing is, Harry, it's only for internal relay.
HARRY: Doctor, I haven't the foggiest notion what you're on about.
DOCTOR: Never mind. It just means that Sarah can't be far away. All we've got to do is find her. Come on!

[Transom]

(The Doctor and Harry step down onto a transom or walkway around the outside of the Wheel. Windows top and bottom reveal the inky blackness of space outside.)

DOCTOR: I think we'll try this way first.

(They head off anticlockwise. Harry points to a door.)

HARRY: I say, what about the armoury?
DOCTOR: Not very likely.

(The transom finishes at a door marked Area Q. Orac from Blake's 7 shouts at them.)

VOICE: This is a sterile area! Keep out!
HARRY: It's just like a hospital.

(The Doctor opens the door. It slides upwards.)

HARRY: Well, ought we, do you think?
DOCTOR: Don't be nervous, Harry.

(We see them through green eyes, then something slides down a space by some steps. Harry reacts.)

DOCTOR: What is it?
HARRY: I saw something moving.
DOCTOR: Nonsense, Harry.
HARRY: I'm positive. I saw something move.
DOCTOR: A trick of the light.

(The door closes behind them.)

HARRY: It wasn't a trick of the light. I saw something moving.

(There is a green trail on the metal grating that is the floor of the transom.)

DOCTOR: It's like the trail left by a gastropod mollusc.
HARRY: A slug?
DOCTOR: Or a snail.
HARRY: That size? Impossible. It couldn't have got through this grille.
DOCTOR: Very interesting. A multinucleate organism?
HARRY: Eh?
DOCTOR: Let's find Sarah first. Come on.

(They move on to the intersection.)

DOCTOR: This looks promising.

(They walk past a notice saying Yellow Badge Personnel Only.)

[Decontamination]

(The room is small and yellow.)

HARRY: She's obviously not in here.
DOCTOR: Decontamination chamber. Might make you feel a bit dizzy.

(It does.)

[Tranquiller room]

(Now we see the wall opposite the now empty alcove. It contains sixteen numbers blocks of six by six units.)

DOCTOR: I think we're getting warm, Harry. Animal and Botanic.

(The Doctor looks through a window in the door so labelled.)

DOCTOR: Of course! That explains everything. Do you realise what this is? Aren't you feeling better?
HARRY: No, I'm not.
DOCTOR: Then pull yourself together, man. This is fascinating! This is a cryogenic repository.
HARRY: Repository? For what?
DOCTOR: Everything. Well, everything they considered worth preserving. Look at this.

(He presses a button next to the numbered blocks and unit five of row two in block eleven comes out.)

DOCTOR: Microfilm. It's a complete record. Music, history, architecture, literature, engineering. Incredible. The entire body of human thought and achievement.
HARRY: Yes, but what's it all for?
DOCTOR: Posterity? I don't know. Why build all this and send it into space?
HARRY: I say, couldn't be some sort of survival kit, could it?
DOCTOR: Survival?
HARRY: Yes, you know, the sort of thing they shove in lifeboats and things.
DOCTOR: You're improving, Harry.
HARRY: Am I really?
DOCTOR: Yes, your mind is beginning to work. It's entirely due my influence, of course. You mustn't take any credit. Now, what's missing?
HARRY: Missing?
DOCTOR: Yes. If we are to assume that some great cataclysm struck Earth, and that before the end they launched this lifeboat, then the one obvious missing element is man himself. What's happened to the human species, Harry?

(A door slides open behind them. They walk over and peer in.)

HARRY: I say, what a place for a mortuary.

[Cryogenic chamber]

(This is the sort of place seen at the top of the episode. White clothed people in plastic pods are arranged in pairs around the wall. From the bottom the tiers are labelled D E and F implying other rooms below and possibly above. Some pods are empty.)

DOCTOR: This isn't a mortuary, Harry. Quite the reverse.
HARRY: Reverse? I'd hardly call it a nursery.
DOCTOR: Cryogenic chamber.
HARRY: What?
DOCTOR: Old principle, but I've never seen it applied on this scale. Look at them.

(A short corridor lined with four pods leads into another chamber.)

DOCTOR: There must be hundreds here.
HARRY: Well, when you've seen one corpse, you've seen them all.
DOCTOR: Corpse? These people aren't dead, Harry, they're asleep. The entire human race awaiting the trumpet blast.

(Harry opens a pod.)

HARRY: Dead as a doorknocker.

[Second chamber]

DOCTOR: Homo sapiens. What an inventive, invincible species. It's only a few million years since they've crawled up out of the mud and learned to walk. Puny, defenceless bipeds. They've survived flood, famine and plague. They've survived cosmic wars and holocausts, and now here they are amongst the stars, waiting to begin a new life, ready to outsit eternity. They're indomitable. Indomitable!

[Cryogenic chamber]

(Harry is peering into the eye of the sleeper.)

DOCTOR: What do you think you're doing, Harry?
HARRY: Sorry to contradict you, Doctor. Not a flicker of life.
DOCTOR: Suspended animation.
HARRY: There are no metabolic functions at all. I mean, look at him. Now, even in the deepest coma, the hair and fingernails continue to grow. The epidermis
DOCTOR: Total suspension, Harry.

(The Doctor closes the pod.)

DOCTOR: You can't survive ten thousand years in a coma.
HARRY: Ten thousand years?
DOCTOR: Fifty thousand years, a hundred thousand. Time is immaterial. It's an amazing sight, isn't it? The entire human race in one room. All colours, all creeds. All differences finally forgotten.
HARRY: Doctor, are you serious? The entire human race?
DOCTOR: Well, it's chosen descendents. The operation must have been meticulously planned. Come on.
HARRY: Where are we going now?
DOCTOR: First to find Sarah, then we're going to shut down the systems. We're intruders here, you know.
HARRY: Just a minute, Doctor. Are you trying to tell that this is where it's all going to end? In here?
DOCTOR: Not end, Harry, just a pause.
HARRY: But there's only a few hundred corpses, er, bodies in here. I mean, what's happened to the rest of humanity? Some global catastrophe?
DOCTOR: Yes, and they saw it coming, and made provision for it as best they could. Don't forget, it's something for you to be proud of.
HARRY: Doctor.
DOCTOR: Yes?
HARRY: Look.

(A green slime trail goes in or out of an air vent by the floor.)

DOCTOR: Oxygen? Radiant heat? But this deep in space? I wonder.
HARRY: Perhaps it's some kind of mould.
DOCTOR: Mould?
HARRY: And that trail we saw in the corridor.
DOCTOR: And that thing you saw moving in the corridor.
HARRY: Dust. That, er, grille thing was a dust extractor. And then we opened the door after umpteen years and caused a bit of a draught.
DOCTOR: Hmm. Very convincing. All the same, I think we'll just check a few of the beds while we're here.
HARRY: What are we checking for, exactly?
DOCTOR: Just to make sure that everything's in order.
HARRY: Right-o.

(They look around the other pods, then Harry opens one.)

HARRY: Doctor!
DOCTOR: What have you found?

(He goes over.)

DOCTOR: Sarah! Oh, Sarah Jane.
HARRY: We can't help her now.
DOCTOR: No. She'll be like that for three thousand years at least. Even if we had a resuscitation unit, it's doubtful that we could revive her now.
HARRY: There must be something we can do. What's would a resuscitation unit look like?

(Harry goes past a sign saying Do Not Enter Cryogenic Area When Light Is On Or Floor Is In Motion and opens a cupboard labelled Medic 2.)

DOCTOR: Very like an oxygen cylinder.

(Harry opens cupboard Medic 1)

DOCTOR: You'll recognise it if there is one.

(And a large green insect falls out.)

Part Two

[Cryogenic chamber]

(Harry kneels beside the huge creature.)

HARRY: Well, it's dead, anyway.
DOCTOR: Very dead. Almost mummified.
HARRY: What is it?
DOCTOR: That's something we can leave till later. No sign of the resuscitation tank?
HARRY: I hardly had a chance to look for one.

(The Doctor takes an orange perspex box from the cupboard.)

DOCTOR: Emergency medical kit, wouldn't you say?
HARRY: A bit beyond me, I'm afraid.
DOCTOR: There must be something there that would help Sarah, but what? What?
HARRY: Doctor, look.

(Pod D1 across the room is active.)

DOCTOR: Of course! They don't need a tank. The resuscitation phase is programmed in.

(The Doctor opens the lid to reveal a woman with yellow shoulder flashes on her white suit.)

DOCTOR: Look, she's starting to breathe.
HARRY: Yes, I think she is.
DOCTOR: No doubt about it.
HARRY: That means there's hope for Sarah. Yes, look, she's moving.

(The woman is holding her arms out. Harry offers the open medical box.)

HARRY: Something you want?

(She takes a ball and inserts it into a star-ended spray gun, then presses it to her heart.)

HARRY: Hey, look, can't I do that for you? Independent sort of bird, isn't she.
DOCTOR: Leave her, Harry.
HARRY: Yes, but she's
DOCTOR: There's nothing you can do. She knows what she's doing.

(The woman slumps then straightens up and steps down from the pod. It switches off. She looks around the room.)

VIRA: Oh! Explain yourselves.
DOCTOR: Well, there isn't very much to explain. We're just travellers in space like yourself.
VIRA: That is not adequate.
HARRY: My name's Sullivan. Surgeon Lieutenant Harry Sullivan, actually. And, er, this is the Doctor.
VIRA: You claim to be med-techs?
HARRY: Sorry?
DOCTOR: My doctorate is purely honorary, and Harry here is only qualified to work on sailors.
VIRA: My name is Vira. I am a first med-tech.
DOCTOR: Well, I'm delighted to hear it. You see, we happen to be in rather desperate need of medical help.

(The Doctor wheels a box over to Sarah's pod.)

VIRA: This female is a stranger.
HARRY: She's a friend of ours. She got caught in the machinery.
VIRA: She was not among the chosen.
HARRY: Well, she's among the chosen now, isn't she.
DOCTOR: Is there any way of reversing the cryogenic process?
VIRA: That can be dangerous. How long since she underwent tissue irradiation?
HARRY: Can't be more than an hour, can it, Doctor? We haven't been here more than an hour altogether.

(Vira puts a circlet on Sarah's head and takes a reading.)

VIRA: Receding neural activity.
HARRY: Is there anything you can do for her?
VIRA: Is she of value?
HARRY: Of value? She's a human being like ourselves! What sort of question's that?
DOCTOR: The answer is yes.
VIRA: Your comrade is a romantic.
DOCTOR: Perhaps we both are.
VIRA: I will inject a monod block.
HARRY: Ah, that'll do the trick, eh?
VIRA: Your colony speech has no meaning.
HARRY: I mean it's bring her round, reverse the process.

(Vira injects Sarah's arm.)

VIRA: She will either survive or die. The action of the antiprotonic is not predictable.
DOCTOR: I see. You've changed her body into a battlefield.
VIRA: Battlefield? I hypoid in classicals, but you dawn-timers have a language all of your won.
DOCTOR: We do seem to have a small communications problem.
HARRY: I wish there was something I could do.
VIRA: It is done. There is nothing further. As she revives, her electrical field will draw power from the bionosphere.

(Vira takes her trolley to another flashing pod, D2. She opens it to reveal a man with red shoulder flashes.)

VIRA: Here is our prime unit.
HARRY: Prime unit?
VIRA: Er, our leader, I think you would say. Noah.
HARRY: Noah? Oh, I see. As in Noah's Ark, eh?
VIRA: It is a name from mythology. His real name is Lazar, but we called him Noah as an amusement.
HARRY: Er, joke?
VIRA: Joke? Oh, yes. There was not much joke in the last days.
DOCTOR: What happened in the last days, Vira?
VIRA: Your colony has no records, no history? Where are you from?
HARRY: London, actually. England. The Earth.
VIRA: That is not possible. The Earth is dead.
DOCTOR: I'm afraid you're probably wrong about that.
VIRA: The solar flares destroyed all life on Earth.
DOCTOR: Ah. Solar flares. I see.
VIRA: Our scientists calculated it would be five thousand years before the biosphere became viable again.
DOCTOR: Oh, the absolute minimum, I'd say. But I'm afraid I've something of a shock for you, Vira.
VIRA: Shock?
DOCTOR: You've overslept by several thousand years. You see, when we came here, we found a massive systems failure.
VIRA: The systems have no capacity for failure.
DOCTOR: Possibly not. But a long time ago, when you were dormant, you had a visitor. Come, I'll show it to you.

(They go over to the dead insect.)

VIRA: Is it from space? How did it get here?
DOCTOR: I don't know yet. But observe the size of the brain pan. It had a purpose in coming here, and once inside, it severed most of the satellite's control systems, including your alarm clock, so to speak.
VIRA: What purpose?

(As the satellite continues on through space, a large maggot with skin like green bubblewrap wriggles its way through the hidden parts. Harry checks on Sarah the old fashioned way. Vira is checking other pods.)

HARRY: Still no change, Doctor.
DOCTOR: No. For once in my life I feel surplus to requirements.

(The maggot uses a pseudopod to unlock a hatch.)

VIRA: Doctor?
DOCTOR: What is it?
VIRA: There's a technical fault in the bionosphere.
DOCTOR: I don't think the fault's at this end. It's in the main power supply.
VIRA: It must be corrected. If his heart stops now, there's nothing I can do.
DOCTOR: Don't worry. I noticed the Ark has a secondary power supply. Harry, you stay here and keep an eye on things.
HARRY: Right-o.
VIRA: Yes, but

(The Doctor leaves.)

VIRA: The Ark was designed to have a negative fault capacity.
HARRY: Gremlins can get into everything, old girl. First law of the sea.

(Back in secondary control, the Doctor works on the console. Noah takes a deep breath.)

HARRY: There you are. What did I tell you? The Doctor's a first class boffin.
VIRA: Good. He will revive soon.
DOCTOR [OC]: Harry?
HARRY: I say, that was quick.

(Harry walks through a doorway into...)

[Tranquiller room]

HARRY: Doctor? Doctor, where are you?
DOCTOR [OC]: In the control room. Have you got the power back on in there?

[Control room]

HARRY [OC]: Yes, we have. Everything's ship-shape now.
DOCTOR: Splendid. The fault seems to be in the main solar stack. I'm just going to take a look.
HARRY [OC]: Right-o.

[Tranquiller room]

HARRY: I say, Doctor, don't be long, will you.

[Cryogenic chamber]

(Vira injects Noah, like she previously did to herself. He wakes.)

NOAH: Vira.
VIRA: Welcome, Commander.
NOAH: It's over. It's over, Vira. You and I are alive again.
VIRA: And together.
NOAH: Who is this?
HARRY: Lieutenant Sullivan, sir.
NOAH: A regressive? Here?
HARRY: I'm no regressive, I'm a Naval officer!

(Sarah's pod hums louder, and Harry goes to check on her.)

HARRY: Sarah!
NOAH: Clearly a regressive. His speech patterns prove it. How did he get here?
VIRA: They claim they are travellers in space.
NOAH: They?
VIRA: There are three of them. Another male called the Doctor, and that female. They say she was irradiated by error.
HARRY: Vira, she's coming round.
NOAH: There was a regressive faction among the volunteers for Colony Nine.
VIRA: With a zero zero survival predic. One generation.
NOAH: Even so, our genetic pool has been balanced, cross-matched, compat-evaluated. Three random units could threaten our survival.
HARRY: Vira!
VIRA: The Council can decide, Noah. The plan had a seven percent stretch factor.

(She crosses to Harry and Sarah.)

HARRY: I think she's going to be all right.

(Vira takes her neural reading.)

VIRA: She will revive soon.
HARRY: Thank heaven for that. Well done. The Doctor will be delighted.
NOAH: Where is the Doctor?
HARRY: Oh, he says you've got a spot of bother in your er. Anyway, he's gone to fix it.
NOAH: What?
HARRY: Er, solar stacks, I think he said.

(Noah leaves.)

HARRY: Yes, she's breathing.

(In the satellite's workings, the Doctor has found the maggot's slime trail. Noah has strapped on a gun belt and headed clockwise along the transom.)

HARRY: Soon have you up and about, old thing. This won't hurt a bit.

(Vira injects Sarah.)

HARRY: Perhaps just a little bit.
VIRA: If you are space travellers as you claim, you should leave now.
HARRY: I say, that's a bit brusque, isn't it? I mean, if it hadn't been for the Doctor
VIRA: Noah will not permit contamination of the genetic pool. All regressive transmitters have been eliminated.
HARRY: Oh, come off it. We're not contaminating anybody.
VIRA: He has the authority to initiate condign action. Personally, I consider your destruction is not necessary.
HARRY: Thanks very much.

(Vira moves away.)

SARAH: Harry?
HARRY: Here. Do you think you can stand? Gently. Mind, there's a step down. There you are.
SARAH: I feel so muzzy.

(Sarah's white suit has blue shoulders, for the record.)

SARAH: What's this? What's happening?
HARRY: It's all right, it's all right.

(The Doctor has found the hatch which the maggot unlocked. Through the glass we see a large writhing green thing with an eye. He locks the hatch again and leaves.)

SARAH: Ten thousand years?
HARRY: Well, according to the Doctor.
SARAH: It's unbelievable, Harry.

(She sees the dead insect.)

SARAH: What's that?
HARRY: Don't know. We found it in the cupboard.
SARAH: In the cupboard?
HARRY: Yeah. It's a sort of galactic woodworm, I suppose.
SARAH: It is dead, isn't it?
HARRY: Oh yes, yes. Been dead for years. It's nothing to worry about.

(Vira opens pod D3. It is empty, glowing red and has a green trail leading out of it.)

VIRA: Come here!
HARRY: What's the trouble?
VIRA: What have you done with Dune?
HARRY: Dune?
VIRA: Where is he? Answer me!

[Control room]

DOCTOR: Ah, there you are. Awake at last.
NOAH: Move away.
DOCTOR: I'm just shutting down the power in the main stack.
NOAH: Touch that switch and I'll atomise you.
DOCTOR: Noah!
NOAH: Earth is ours.
DOCTOR: My dear man, if you think for one moment we're laying claim to Earth, you couldn't be more mistaken. We're here to help you.
NOAH: By deactivating the main solar stack?
DOCTOR: Precisely. There's something trapped in the stack, Noah, but at the rate its absorbing energy it won't be trapped for long. The stack must be shut down. Well, if you'd been down there with me, Noah, you

(Noah fires his ray gun and the Doctor falls. Down in the solar stack, the green stuff breaks the glass on the hatch.)

[Cryogenic chamber]

VIRA: The revivification pattern was inbuilt. Dune was allotted pallet three.
SARAH: Oh. Well, perhaps he recovered early?
HARRY: Yes, that's possible, isn't it? I mean, well, after all, some people need more sleep than others.
NOAH [OC]: Vira? Hear me, hear me.

[Tranquiller room]

VIRA: Yes, Noah? Where are you?

[Control room]

NOAH: Main control. I found the Doctor here about to sabotage the power system. He's been dealt with.

[Tranquiller room]

VIRA: Noah, we have a problem. Pallet three is empty.

[Control room]

NOAH: Explain.
VIRA [OC]: Technician Dune is missing. There is no explanation.
NOAH: The explanation is that the regressives have taken him. Any other problems?

[Tranquiller room]

VIRA: No, Commander.

[Control room]

NOAH: Then proceed with the schedule. I'm about to check the power stacks.

[Tranquiller room]

VIRA: Commander Noah will question you on his return. Complete truth is advisable.

(Vira goes into the cryogenic chamber.)

HARRY: Cocky bunch, aren't they.
SARAH: What do you think's happened to the Doctor?
HARRY: I think we'd better find out, don't you?
SARAH: Yes.
HARRY: Come on, then.

(Down in the power stacks, Noah approaches the now broken glass of the hatch with his gun ready. He turns and fires at something, but a green pseudopod lashes out and leaves slime on his left hand. He collapses.)

[Control room]

(Sarah and Harry run in.)

SARAH: Doctor! What's wrong with him?
HARRY: Haven't a clue, Sarah.
SARAH: Well, you're supposed to be a doc
HARRY: Shush.

(Harry listens to the Doctor's hearts.)

HARRY: He's alive, anyway. His hearts are beating.
SARAH: Oh, Doctor.
HARRY: It's incredible. He's absolutely rigid.
SARAH: Harry, please, do something.
HARRY: But there's no response at all.
DOCTOR: You wouldn't find it so amusing.
SARAH: Oh, Doctor!
DOCTOR: Ah, Sarah, you're back. Splendid. Where's Noah? Shot me, did he? Cut off in mid sentence. I might have been saying something important. I was saying something important!
SARAH: Look, are you all right?
DOCTOR: What? Blinding headache, that's all. I hate stun guns. Where is he?
SARAH: Who?
DOCTOR: Noah, of course. Who else?
HARRY: We overheard him on the intercom thing saying something about checking the solar stacks.
DOCTOR: What? The idiot. Quick, there might be still time.
HARRY: Are you sure you're all right?
DOCTOR: Never mind about me, Harry, there's a man in danger.

(Noah wakes up, and with his left hand jammed firmly in his trouser pocket, leaves the power stacks.)

[Transom]

(Walking clockwise.)

HARRY: Strange how they've given us the run of the ship. Why doesn't Vira try and stop us?
DOCTOR: Not her function, Harry.
HARRY: How do you mean?
DOCTOR: By the thirtieth century, human society was highly compartmentalised. Vira is a med-tech, and I suspect we're an executive problem.

(Noah steps out in front of them.)

NOAH: Right, Doctor. But not a difficult on. You can easily be eliminated.
DOCTOR: Unlike the thing you saw in the solar stack, eh, Noah?
NOAH: I saw a pathetic attempt at sabotage. The observation port is damaged.
DOCTOR: Then it's escaped. We're too late.
SARAH: What's escaped?
NOAH: Turn about. We will return to the cryogenic section.
DOCTOR: You're absolutely right. There's no time to lose. Come on.

[Cryogenic chamber]

(At pod D6, Vira gives another man the wake up injection. He has green shoulder flashes.)

LIBRI: Vira.
VIRA: Welcome.
NOAH: Welcome, Libri.
LIBRI: Keep back. Keep back!
NOAH: What's the matter with him?
LIBRI: Keep back!
NOAH: Is it his mind?
VIRA: No, his reactions were normal. Libri
LIBRI: Keep away!
VIRA: This is Noah. You remember Commander Noah?
LIBRI: I'm sorry. I saw something standing there.
DOCTOR: What was it you saw, Libri?
NOAH: Silence! You're here to answer questions, not ask them.
LIBRI: It was horrible. A shape. I'm sorry. I'm all right now.
VIRA: Temporary neuro-ocular confusion.
DOCTOR: The process is much too slow. They're not going to make it.
NOAH: No further warnings.
HARRY: Yes, you'd shoot too, wouldn't you. Nice fellow.
NOAH: Libri, keep these three under guard. Kill them if they give any trouble.
LIBRI: Yes, sir.

(Libri takes the gun from Noah.)

VIRA: Noah, where are you going?
NOAH: The system must be shut down.
VIRA: What?
NOAH: The revivification must be stopped.
VIRA: Why? I don't understand.
NOAH: It is an order. I am the commander.
VIRA: But the first phase isn't completed, and we need the technical crew, Noah, to operate the station.
NOAH: Yes. No! No, the plan is changed. Hear me, hear me, the plan is changed.
VIRA: Noah, what is it? Is it something to do with Dune?
NOAH: Dune?
VIRA: Technician Dune. I reported him missing.
NOAH: But I'm here. I am Dune.
VIRA: What?
NOAH: The system must be shut down. No more aliens!

(Noah leaves.)

VIRA: Noah, come back!
DOCTOR: He must be stopped.
VIRA: Something has happened to his mind. There was a power fault during his revival.
DOCTOR: Get after him, man.
LIBRI: No, no, he gave me an order.
DOCTOR: Don't be an imbecile. Tell him, Vira.
VIRA: There is no procedure for stopping the revivification programme. It could be damaging, Libri.
LIBRI: But he is our commander.
DOCTOR: Can you be sure?
LIBRI: What?
DOCTOR: When you first saw him, you had a subconscious impression, you said, of something horrible. That wasn't Noah, was it?
LIBRI: No.
DOCTOR: Believe me, he must be stopped.

(Vira nods, Libri leaves.)

DOCTOR: Good.
VIRA: It's not advisable for you to try and escape.
DOCTOR: You take some convincing that we're on your side, don't you. Now, what's all this about a missing technician?
VIRA: Pallet three. I found it empty.
SARAH: Noah thinks that we're to blame.
HARRY: Chap's jumped ship, that's all. Happens all the time.
SARAH: Oh, come on. A space satellite's a bit different from a ship, Harry.
HARRY: You know, Sarah, I bet you there's the equivalent of a dinghy missing.
DOCTOR: It's not quite empty.

(The aerial of the small R/T has now been used to pick up a long strip of green something.)

VIRA: Oh, what's that?
DOCTOR: Membrane.
SARAH: Membrane?
DOCTOR: Part of the eggshell.
VIRA: Where's it from?
DOCTOR: It's almost too horrible to think about.

(The Doctor goes over to the giant insect.)

DOCTOR: The egg tube is empty.
VIRA: That thing?
DOCTOR: The progenitor. The queen coloniser.
SARAH: I don't understand.
DOCTOR: Ever heard of the Eumenes?
HARRY: Eumenes? One of our frigates.
DOCTOR: It's a genus of wasps that paralyses caterpillars and lays its eggs in their bodies. When the larvae emerge, they have a ready made food supply. Strange how the same life patterns recur throughout the universe.
HARRY: Doctor, are you saying that that slug thing?
DOCTOR: Ciliated larvae, Harry. Dune was power systems technician, I imagine.
VIRA: Yes, but how did you know?
DOCTOR: It, or they, went straight to the solar stack.
VIRA: You mean Dune's knowledge
DOCTOR: Has been thoroughly digested, I'm afraid.
SARAH: Don't make jokes like that, Doctor.
DOCTOR: When I say I'm afraid, Sarah, I'm not making jokes.

[Secondary control]

LIBRI: Commander.
NOAH: Give me the gun.
LIBRI: I'm sorry, Commander.
NOAH: Give me the gun.
LIBRI: No, you're not well.
NOAH: I order you.
LIBRI: I can't. Please, Commander, stay back. Please.

(Noah is within arms reach of Libri.)

LIBRI: Don't force me to

(Noah takes the gun.)

NOAH: You fool, Libri.

(Noah shoots him and holsters the weapon. He walks into the control and takes his left hand out of his pocket. The sight of the green thing it has become revolts him.)

Part Three

[Control room]

WOMAN [OC]: Hello, Space Station Nerva. This is the Earth High Minister. The fact that you are hearing my voice in a message recorded thousands of years before the day in which you are now living, is a sure sign that our great undertaking, the salvation of the human race, has been rewarded with success.

[Cryogenic chamber]

WOMAN [OC]: You have slept longer than the recorded history of mankind, and you stand now at the dawn of a new age. You will return to an Earth purified by flame, a world that we cannot guess at. If it be arid, you must make it flourish. If it be stony, you must make it fertile. The challenge is vast, the task enormous, but let nothing daunt you.
HARRY: Sounds like a sort of pre-match pep talk.
WOMAN [OC]: Remember, citizen volunteers, that you are the proud standard bearers of our entire race.

[Control room]

WOMAN [OC]: Of the millions that walk the world today, you are the chosen survivors. You have been entrusted with a sacred duty, to see that human culture, human knowledge, human love and faith, shall never perish from the universe.

(Noah smashes his green appendage against the console, trying to kill the alien thing.)

WOMAN [OC]: Guard what we have given you with all your strength.

[Cryogenic chamber]

WOMAN [OC]: And now, across the chasm of the years, I send you the prayers and hopes of the entire world. God speed you to a safe landing.

(Vira returns to her duty.)

HARRY: Well, I bet that did your female chauvinist heart a power of good.
SARAH: Why?
HARRY: Well, I mean, fancy a member of the fair sex being top of the totem pole.
NOAH [OC]: Vira! Vira!
VIRA: Noah!

[Tranquiller room]

VIRA: Yes, Commander?
NOAH [OC]: Vira, hear me. This is an order. Expedite revivification. Commence main phase now.
VIRA: But Noah, the safety checks

[Control room]

NOAH: Ignore safety checks! We, you, are in great danger. Get our, your people to the Earth before
VIRA [OC]: Noah?
NOAH: Before the Wirrn. Vira, take command. Now hear me. You take command!

[Tranquiller room]

VIRA: What has happened? Commander, are you there?

[Control room]

NOAH: The Wirrn are here. They will

(Noah loses the fight against the green thing taking over his body.)

NOAH: We shall absorb the humans. The Earth shall be ours.

[Tranquiller room]

VIRA: Noah! Noah!

[Control room]

NOAH: Vira. Vira, there's no time. They're in my mind, getting stronger. Libri is dead. You will all die. Must save our people. You must!

(Noah fights against his left arm again.)

VIRA [OC]: Noah? Noah!

[Tranquiller room]

HARRY: The chap sounds in a bad way.
VIRA: What did he mean, they're in his mind?
DOCTOR: Absorb? We shall absorb the humans? Endoparasitism?
SARAH: He talks to himself sometimes because he's the only one who understands what he's talking about.
DOCTOR: If the Wirrn can do that, we've no chance at all. Complete physical absorption.
VIRA: Of us?
DOCTOR: They'll literally eat us alive. Vira, I must talk with Noah. You'd better come with me. He trusts you.
VIRA: My duty is to supervise the revivification.
DOCTOR: No. Noah has passed the command to you. Your duties have been widened.
VIRA: What is your intention?
DOCTOR: To find out exactly what it is we're facing. And only Noah knows that.
VIRA: But I cannot leave until the last of our technical section have awakened.
DOCTOR: Harry can handle that for you, can't you, Harry?
HARRY: Well, I
DOCTOR: Well, you've watched Vira. You know the procedure.
HARRY: Yes, I
VIRA: One gramme of scropholine when the neural register enters the red zone.
HARRY: Right.
DOCTOR: He'll be all right.

(The Doctor leaves.)

VIRA: And the injection must be right over the pectoralis major.
HARRY: Ah, yes, now that I do understand.
SARAH: Good luck.
DOCTOR [OC]: And Sarah, you stay and help Harry.

(Vira leaves.)

HARRY: Yes. Come along, Nurse Smith.

[Cryogenic chamber]

(Harry goes over to the pod Vira was previously at. There are red lights flashing under the feet of the man inside.)

HARRY: Yes, you see, this chap's in the red zone, so

(Harry prepares the injection.)

SARAH: Hey, there's another one seems to be awake here.
HARRY: Well, after ten thousand years, Sarah, he can't be in that much of a hurry.
SARAH: Oh, I hope you know what you're doing.
HARRY: Oh, yes, dead simple really. Medicine by numbers.
SARAH: Oh, yes, dead simple.
HARRY: It's just a question of fixing a fresh ampoule thing into here.

[Transom]

(The door dividing the cryogenic section from the rest slides up to reveal Noah. His left arm is now a pseudopod and half his face is green. He is half-crouching.)

NOAH: Keep back! Don't touch me!
VIRA: Noah.
NOAH: Keep back, I said!
DOCTOR: Noah, tell us one thing. How much time do we have?
NOAH: Time?
DOCTOR: Before the Wirrn reach their adult form?
NOAH: It feels near, very near. The tearing free and then the great blackness rushing through.

(Noah drops his gun as he passes between them and leaves.)

VIRA: Noah and I were pair-bonded for the new life.
DOCTOR: Let's go back.

[Cryogenic chamber]

(Two men are being briefed on the situation.)

ROGIN: (red shoulder flashes) Dune and Libri? And Noah?
SARAH: I'm sorry. It must be a terrible shock for you.
LYCETT: (green shoulder flashes) So there's just two of us left to check the ship?
SARAH: And Vira. She's taken command.
LYCETT: Where is she?
SARAH: She's gone with the Doctor. They're trying to contact Noah.
ROGIN: There's been a snitch up. Didn't I tell you, Lycett? Five thousand years ago I said there'd be a snitch up.
LYCETT: Ten thousand.
ROGIN: Oh, beautiful. We should have taken our chance with the solar flares and gone into the thermic shelters. We'd have been happily dead by now.
LYCETT: What was it that killed them? Their lungs, was it?
HARRY: Hmm?
LYCETT: Dune and Libri. We were told our lung tissue might atrophy.
HARRY: Well, no, actually.
SARAH: Something got in here.
HARRY: That's right. Some sort of space creature.
SARAH: It cut through your alarm clock system.
ROGIN: What?
SARAH: Look. Oh, it's okay. It's dead.
DOCTOR: But unfortunately, its larvae are still very much alive.
LYCETT: Vira!
ROGIN: Vira, it's gone wrong!
VIRA: Welcome, Lycett, Rogin. You feel well?
LYCETT: Yes, Commander.

(A giant green larva wiggles along the transom. Harry helps the Doctor move the Wirrn corpse into the middle of the chamber.)

HARRY: What are we going to do with it?
DOCTOR: How much anatomy do you remember, Harry?
HARRY: Quite a lot, I think, but you need a blooming entomologist for this thing.
DOCTOR: We need to find its weaknesses and we need to find them quickly.
VIRA: Can we help?
DOCTOR: Not at the moment, thank you.
VIRA: Then we will commence the main phase. Lycett, Rogin.

(The three Nirvans leave.)

DOCTOR: What was that she just said?
SARAH: They're going to start the main phase.
DOCTOR: What? (to Harry) Carry on with that thoracic incision. Not too deep.

[Tranquiller room]

LYCETT: But the safety checks?
VIRA: We shall override them.
ROGIN: Why?
LYCETT: We can't.
VIRA: That is my decision. Now, take your operating station.
DOCTOR: Vira, the main phase must wait.
VIRA: Noah said we should expedite the revivification programme and get our people to work.
DOCTOR: Noah was wrong. How long would it take?
VIRA: Seventy two hours for complete revivification, another twenty four to evacuate the Ark.
DOCTOR: Four whole days? At the rate at which the Wirrn are developing, they'll have pupated to imago long before then, and you know what that means.
VIRA: We must try!
DOCTOR: You can't do it, Vira. The Ark will be crawling with those creatures within hours.
VIRA: Doctor, the fate of all humanity might be decided within the next few hours.

(She nods to Lycett and Rogin, who start work on the console.)

DOCTOR: Vira, if you fail, your people will die in pain and fear. If I fail, they'll die anyway, but at least only the six of us will know anything about it.
VIRA: You have an alternative plan?
DOCTOR: Between the larval and imago forms, there must be a pupal stage. Now, the Wirrn will be dormant and defenceless. If we can find their weaknesses?
VIRA: We might destroy them?
DOCTOR: Yes.
VIRA: Very well. Stand down.
DOCTOR: Good.
LYCETT: There's a power flutter in section four, Commander.
VIRA: What does that indicate?
LYCETT: Some external fault. Shall I check the stacks?
DOCTOR: No! The larvae have taken over the infrastructure. They seem to need solar radiation.
ROGIN: We should have stayed on Earth, Lycett. I liked the Earth. I like heat.

[Cryogenic chamber]

HARRY: Curious lung structure, Doctor. Look at it.
DOCTOR: Yes, fascinating. A superb adaptation.
SARAH: What is it?
DOCTOR: Obviously the creature's lungs recycle the wastes, almost certainly by enzymes. Quite wonderful. Carbon dioxide back to oxygen.
SARAH: You mean the way plants make oxygen?
DOCTOR: Exactly right. It must live in space, probably just occasionally visiting a planetary atmosphere for food and oxygen, the way a whale rises from the ocean.
HARRY: Judging by the size of his mandibles, this chap doesn't live on plankton.
DOCTOR: No.
VIRA: Noah spoke of a great blackness rushing in. He meant space, but how did he know?
DOCTOR: He now has the race memory of a Wirrn. Symbiotic atavism to be precise. I'm going to need your help now, Vira.

(The Doctor has peeled the outer layer off one of the Wirrn's compound eyes.)

[Tranquiller room]

DOCTOR: Do you have any spare extension leads, Rogin?
ROGIN: Yes, but what do you want
DOCTOR: Hurry, man. Fetch them.
VIRA: What are you going to do, Doctor?
DOCTOR: A little experiment. Circuit display, Lycett.

(The circuits come up on a circular monitor.)

VIRA: It's forbidden to alter those circuits. I need the neural cortex amplifier. Not for long, don't worry.

(Meanwhile, something big and green is pulsing next to a grille. The Doctor attaches leads to the eye membrane.)

DOCTOR: Right, switch on the video circuit, Lycett. It'll take a little time to warm up.
HARRY: Doctor, what are you trying to do, exactly?
DOCTOR: Sometimes latent neural impressions can be revived.
HARRY: Really?
DOCTOR: Yes.
HARRY: I've never heard of that.
DOCTOR: Advanced technology. Gypsies used to believe that the eye retained its last image after death. Not so far out. No, it's not going to work. Switch off, Lycett.
SARAH: Now what?
DOCTOR: It should work. The coil isn't giving a strong enough stimulus. I'll have to link in my own cerebral cortex. That's the only thing.
VIRA: That is highly dangerous.
DOCTOR: I know. Two more leads, Rogin.
VIRA: The power could burn out a living brain!
DOCTOR: I agree. An ordinary brain. But mine is exceptional.
VIRA: I cannot permit it. The shock might kill you.
DOCTOR: I think not. Unless, of course, the experiment was interrupted. That could be dangerous.
SARAH: Do you have to do it, Doctor?
HARRY: Yes, why take the risk?
DOCTOR: If I can find out what it was that killed that creature, we might have a chance of fighting the Wirrn. That's our only hope.
SARAH: Yes, but do you have to be the one
DOCTOR: It's not just our existence that's at stake, Sarah. It's the entire human race.

(The Doctor fastens electrodes to his temples.)

DOCTOR: It may be irrational of me, but human beings are quite my favourite species. Vira.
VIRA: Yes, Doctor?
DOCTOR: Take this. (the gun) Don't hesitate to use it if anything goes wrong. You won't have much time.
HARRY: What do you mean?
DOCTOR: Switch on, Lycett. Lycett?

(Lycett switches on and the Doctor tenses in pain.)

HARRY: Doctor!
VIRA: He's joining his mind to the Wirrn. He could remain a part of it forever.
DOCTOR: Look, it's working.

(There is a noise in the cryogenic chamber.)

LYCETT: What was that?
ROGIN: We'd better look.

(Rogin and Lycett leave. The monitor shows the Ark in orbit of Earth, with the point of view getting closer.)

[Cryogenic chamber]

LYCETT: Over here.

(A ventilation grille between D4 and D5 has been smashed outwards, and a green trail leads into the room. )

LYCETT: Case hardened diranium, bent like tin.
ROGIN: Lycett, look out behind you!

(The larva towards him. Lycett scrambles into an empty pod.)

ROGIN: Shut the door! Shut the door!
HARRY: What's going on?
ROGIN: Get out!

[Tranquiller room]

ROGIN: They've killed Lycett!

(He closes the door to the cryogenic chamber.)

ROGIN: There's some sort of huge grub in there.
HARRY: Stop the experiment.
SARAH: No, you can't! You'll kill him!
VIRA: The armoury, Rogin. Get the fission guns.
ROGIN: Right.
HARRY: I'll come with you.

(On the monitor is an image of the intruder defence mechanism sending its electricity into the observer. An insect leg opens the panel in the control room to cut the wires. Whatever is currently in the cryogenic chamber is thumping on the door.)

VIRA: Hurry, Rogin!
SARAH: That door won't hold much longer.

(The monitor now shows the Wirrn approaching a cryogenic pod and opening it.)

VIRA: Dune.

[Transom]

(The doorway to Area Q slides up as half-transformed Noah comes out behind Rogin and Harry.)

NOAH: Fools! Human fools!

(Rogin fires his weapon first, and Noah recoils from the electricity. Rogin continues to fire as the door closes again, cutting Noah off from them.)

[Tranquiller room]

(Something very tall and green is starting to ooze round the edge of the door. The monitor is now blank so Sarah switches it off and removes the electrodes from the Doctor's head.)

SARAH: Help me with him, Vira.
VIRA: Wait. Come away.
DOCTOR: Wirrn. Wirrn.
VIRA: Doctor.
DOCTOR: Wirrn!
VIRA: Doctor! Doctor!

(Vira raises the weapon.)

SARAH: No, you can't! I won't let you!
DOCTOR: Can't what? Is it time to get up?
SARAH: Doctor, you're going to be all right.
DOCTOR: Is that noise in my head?

(Harry and Rogin enter, and they and Vira start firing at the green thing pushing the door open. But the door opens fully and it does not retreat.)

HARRY: Doctor, come back.
SARAH: Doctor, don't! Doctor! Doctor!

(Sarah pushes the Doctor away from the giant larva.)

DOCTOR: Aim lower!

(They do, and the thing falls to the floor and retreats. The men close the door again.)

ROGIN: It's gone back through the grille.
HARRY: That was a close one. You all right, Sarah?
SARAH: Yes.
HARRY: Doctor?
DOCTOR: Why? Why have they gone over to the attack?
VIRA: They want to destroy us.
DOCTOR: But they've only to wait. In their adult form they'll be a thousand times deadlier. Fission guns will have no effect then.
SARAH: How many of them will there be?
DOCTOR: At a hatching? A hundred.
HARRY: A hundred? We won't stand a chance. How can we fight a hundred of those?
DOCTOR: Electricity. Only by electricity. That's the one thing I found out.
SARAH: Electricity? How
DOCTOR: Yes. It was the auto-guard that killed the queen. Half a million volts.
HARRY: We found the queen in the cupboard.
DOCTOR: Amazing will power. I could feel it struggling against death until its task was done. Yes. Rogin, is there any way we can electrify the infrastructure?
ROGIN: Not from here, Doctor. We'd have to run cables from the control centre.
DOCTOR: Control centre? Right, let's go!
HARRY: You can't go that way, Doctor.
ROGIN: Noah's waiting out there. Put one foot inside the transom and you'll be dead.
DOCTOR: Yes, I was forgetting Noah's extra mobility.
VIRA: We're trapped.
DOCTOR: No. The Wirrn are using Dune's knowledge of the Ark. Perhaps there's something he didn't know.
ROGIN: Dune was first tech. He knew it all.
VIRA: He helped design the systems.
DOCTOR: Nobody knows it all. Perhaps he's forgotten that these transmats are reversible?
ROGIN: Oh ho, that's clever.
DOCTOR: Isn't it? And as you appreciate it, Rogin, you can go first. I'll give you a hand. Come on.

(Rogin climbs over the console into the tranquiller alcove.)

ROGIN: Oh well, I never liked it here anyway.

(The Doctor operates the controls and Rogin vanishes.)

DOCTOR: You next, Harry.

[Control room]

(Rogin watches Harry appear on the couch.)

HARRY: I say!
ROGIN: Are you all right?
HARRY: What a marvellous way to travel.
ROGIN: It always sets my teeth on edge.

[Tranquiller room]

(The Doctor is about to send Sarah when the power goes off.)

DOCTOR: That was a power drain. Hello, control centre?
ROGIN [OC]: Hello, Doctor. We've got a power failure.
DOCTOR: It's general, then. Do you have a fault reading?
ROGIN [OC]: Section four. That's the secondary stack. There's no power coming from there at all.

(His voice fades out and the room gets darker.)

VIRA: All power systems are self repairing.
DOCTOR: Hmm. Malicious damage excluded.
SARAH: Oh well, obviously I am not going anywhere. Help me, Doctor.

(The Doctor helps Sarah down from the alcove.)

VIRA: The oxygen pumps have stopped.
DOCTOR: Of course. In their pupal stage, the Wirrn don't need oxygen. An easy way of killing us.
VIRA: Well, suffocation is not the most unpleasant death.
DOCTOR: What? We're not finished yet. You two stay here.
SARAH: Where are you going?
DOCTOR: The infrastructure. If they've entered the pupal stage, they'll be dormant.

(The Doctor cranks the door open by hand. Give me a chance to get down there and switch the power back on. )

VIRA: You're forgetting Noah.
DOCTOR: No, I'm not. I think his job's done now. He'll be metamorphosing too.

[Power stacks]

(The Doctor makes his way along the catwalks to where two six foot pupae cases stand by the observation window into the solar stacks. He is about to open the hatch when he hears a noise, and turns to see a full grown Wirrn approaching. We catch a glimpse of Noah's face inside it.)

Part Four

[Power stacks]

(The Wirrn is struck by weapons fire. It is Vira, with Sarah. The Doctor joins them on the steps.)

SARAH: Run, Doctor! Run!
WIRRN: Stay, Vira. Stay. Abandon the Ark, Vira. Take the transport ship. Leave now. If you stay, you are doomed.
VIRA: That would be desertion.
WIRRN: Then you must die, all of you. When the Wirrn emerge, you will be hunted down and destroyed, as you destroyed us.
SARAH: We've never destroyed. What does he mean?
WIRRN: Long ago, long ago humans came to the old lands. For a thousand years the Wirrn fought them, but you humans destroyed the breeding colonies. The Wirrn were driven from Andromeda.
VIRA: Andromeda? So our star pioneers succeeded?
WIRRN: Since then we have drifted through space, searching for a new habitat. The Ark is ours. It must be ours.
DOCTOR: But the Wirrn live in space. You don't need the Ark.
WIRRN: You know nothing. We live in space, but our breeding colonies are terrestrial.
DOCTOR: But you could leave the Ark and go on. There's plenty of room in the galaxy for us all.
WIRRN: In the old lands, senseless herbivores, cattle, were the hosts for our hatchlings. Now we shall use the humans in the cryogenic chamber. We shall be informed with all human knowledge. In one generation, the Wirrn will become an advanced technological species. We shall have power!
VIRA: That proposition is genetically impossible.
WIRRN: I already have all Dune's knowledge. High energy physics, quantum mechanics. Every ramate in the next hatching of Wirrn will possess the sum of your race's learning. That is why you must die.

(One of the pupae starts to split.)

DOCTOR: Time to leave.
WIRRN: Leave the Ark, Vira, or die with the rest of your race.

[Control room]

HARRY: Well, something must have happened to them.
ROGIN: And if we go out there, it might happen to us.
HARRY: Well, I think we ought to investigate.
ROGIN: There are no lights in the rest of the Ark, Harry. After what happened to Lycett, I want to see where I'm putting my feet.

(Harry glances down at his socks.)

HARRY: You should worry.

(There is a noise outside. Rogin grabs his weapon and stand by the side of the door.)

HARRY: Doctor! It's taken you long enough to get here. I was worried stiff.
DOCTOR: We bumped into Noah.
ROGIN: Again?
DOCTOR: Yes. Quite chatty this time. Garrulous, even.
VIRA: You've got the power on.
ROGIN: No, Commander, I'm using photon energy. There's just enough to run the lights.
HARRY: Well, what did Noah say?
SARAH: Vamoose or stick around and get killed.
HARRY: I'm ready to go. Doctor?
DOCTOR: Anyone for a jelly baby?
HARRY: Well, look, why don't we all just pile into the TARDIS?
DOCTOR: No?
VIRA: TARDIS?
HARRY: Yes. A sort of spaceship thing in there. Plenty of room for all of us.
DOCTOR: Vira has no intention of leaving here, have you, Vira?
VIRA: I can't.
DOCTOR: Of course you can't, so neither can we.
SARAH: Ah well, that settles us.
DOCTOR: Besides, we can't let the Wirrn eat through the cryogenic sleepers as though they were a lot of
HARRY: Jelly babies?
DOCTOR: Exactly. Let them be turned into a lot of surrogate humans? It's the most immoral suggestion I've heard for a century.
ROGIN: How can we stop them?
DOCTOR: High voltage power. If we can somehow send enough electrical power through the bulkheads of the cryogenic chamber
SARAH: Like an electric fence?
DOCTOR: Yes. The Wirrn would never dare to cross it. The only problem is we don't have any electrical power and they control its sources, the solar stacks.
HARRY: Well, we can forget that idea then, can't we.
SARAH: Doctor
DOCTOR: Unless we can lure them out of the infrastructure.
SARAH: No, wait a minute.
VIRA: How can we do that?
DOCTOR: Bait. Human bait! If one of us could distract them for a few moments, I might be able to get down there and turn the power on.
SARAH: Doctor, will you listen?
DOCTOR: Sarah, we're trying to make a plan.
VIRA: It wouldn't work, Doctor. If they have Dune's knowledge, they'd simply turn it off again.
DOCTOR: Not if we electrify the switch itself.
ROGIN: That would take a long time. Those switch boxes are non-conductive.
DOCTOR: Well we can't do without oxygen indefinitely. What was that you were trying to say, Sarah?
SARAH: I was just wondering about the transport ship that Noah mentioned.
DOCTOR: What about it?
SARAH: Well, surely it has its own power system, doesn't it?
ROGIN: Four granovox turbines! That ship can generate twice the power of the Ark.
DOCTOR: How can we reach it?

(Vira calls up the Ark's schematics on the monitor.)

VIRA: Here's the connecting ramp. It's less than a hundred metres from this control room.
ROGIN: The only trouble is, how do we run a cable from the ship to the cryogenic chamber? If it's in the open, they'll cut it.
DOCTOR: Aren't there conduits?
ROGIN: Yes, but they're only about this wide.

(Rogin indicates a small shoulder width.)

ROGIN: We'd need a mechanical cable runner.
SARAH: Why can't I take that cable through? Well, I'm about that wide.
HARRY: It's hardly a job for you, Sarah.
ROGIN: I reckon she might just squeeze through, Doctor.
DOCTOR: Good girl, Sarah. Come on, we'd better hurry. The Wirrn are going to start moving any moment. You four go to the transport ship and I'll start wiring up the cryogenic chamber.

[Under the transport ship]

(Rogin carries a large coil of cable into the blast area. The exhausts of the shuttle are above them.)

ROGIN: This is the transport ship, and here's the conduit. We'll connect one end up here, and you'll have to drag the other end through. Do you think you can manage it?
SARAH: I'll have to.
VIRA: Good luck.

(Rogin opens a hatch in the base of the shuttle, and a ladder is lowered down. He climbs up.)

HARRY: It seems very narrow, Sarah. Does that lead straight to the cryogenic chamber?
VIRA: No, there are many junctions.
HARRY: How's she going to find her way in the dark and everything?
VIRA: We'll give her a two-way radio from the ship. We have a plan of the conduits. We can guide you.
ROGIN [OC]: All right, Commander.

[Transport ship]

(Vira climbs up to join Rogin.)

ROGIN: Beautiful. We could head straight home to Earth now. Nothing could stop us.
VIRA: You've completed all checks?
ROGIN: Yes, Commander.
VIRA: Right. Waste no more time. Give the girl the radio.

(In the cryogenic chamber, the Doctor is attaching cables when he hears a noise. It is a Wirrn entering the Tranquiller room next door. The Doctor shrugs and continues with his work.)

[Under the transport ship]

(Harry is playing out cable into the conduit when it stops.)

HARRY: How are you doing, old girl?
SARAH [OC]: How do you think I'm doing, twit?
HARRY: I'm sorry, I thought you were stuck.

(The cable moves on. In the cryogenic chamber, the Doctor is hiding in a pod as the Wirrn looks around.)

[Transport ship]

SARAH [OC]: Hello, Rogin? Hello? I've reached another junction. A sort of Y fork.
ROGIN: That's good. You're more than half way there. Now, take the right conduit. Do you understand?
SARAH [OC]: Got you. (grunts)
ROGIN: Yes. Sarah?
SARAH [OC]: Yes?
ROGIN: The section you're in now runs right through the infrastructure. Move as quietly as you can.

[Conduit]

SARAH: Understood.

(Sarah inches forward carefully, pulling herself along with her arms. She spots a Wirrn through a small grille, and it sees her. She tries to hurry. The Wirrn has left the cryogenic chamber, and the Doctor has completed wiring the place up. He opens a triangular hatch above the smashed grille and listens.)

[Transport ship]

(Harry climbs up the ladder.)

ROGIN: Now, it's the second opening you come to on your left. You understand?
SARAH [OC]: Yes. Rogin, is it much further?
ROGIN: No, about another fifteen metres. You're almost there.
SARAH [OC]: Oh, I hope so. Don't think I can go on much longer.
VIRA: Yes, you can.
HARRY: Come along, Sarah. Stick at it.
SARAH [OC]: That's the trouble.

[Conduit]

SARAH: I keep getting stuck!
HARRY [OC]: Marvellous thing about old Sarah. Terrific sense of humour.

[Cryogenic chamber]

(The Doctor can hear her grunting.)

DOCTOR: Come on, Sarah. Hurry!
SARAH [OC]: Doctor, where are you?
DOCTOR: Straight ahead. Look, I'll shine a light.

(He points the torch into the conduit.)

DOCTOR: Can you see?
SARAH [OC]: Yes! Oh, Doctor, I can't move!
DOCTOR: Of course you can. You've got this far.
SARAH [OC]: No, I'm stuck!
DOCTOR: Don't panic, Sarah. Don't panic. Ease round and try again.

[Conduit]

SARAH: I'm jammed. I can't move forward or back.
DOCTOR [OC]: Oh, stop whining, girl. You're useless.
SARAH: Oh, Doctor.

[Cryogenic chamber]

DOCTOR: Oh, Doctor. Is that all you can say for yourself? Stupid, foolish girl. We should never have relied on you. I knew you'd let us down.

[Conduit]

DOCTOR [OC]: That's the trouble with girls like you. You think you're tough, but when you're really up against it, you've no guts at all.

(Sarah manages to pull herself forward again.)

[Cryogenic chamber]

DOCTOR: Hundreds of lives at stake and you lie there, blubbing.
SARAH [OC]: You wait till I get out!

(Sarah's hands emerge from the conduit.)

SARAH: I can manage. I don't need your help, thank you!
DOCTOR: Yes, you do. Yes, you do.

(The Doctor pulls her out.)

SARAH: Ow.
DOCTOR: Splendid.
SARAH: Go away.
DOCTOR: You've done marvellously, Sarah. I'm very proud of you. I really am very proud of you.
SARAH: What? Conned again. You're a brute.
DOCTOR: Me, a brute?
SARAH: Yes.
DOCTOR: Don't be ungrateful. I was only encouraging you. Come on.
SARAH: Oh, hello, Rogin?

[Transport ship]

SARAH [OC]: The Doctor's connecting the cable now.
ROGIN: Beautiful. Let me know when to switch the power through.

[Cryogenic chamber]

DOCTOR: Close the door to the access chamber.
SARAH: Right.

(Sarah takes off her headset, goes over to the door, and sees a Wirrn in the tranquiller room. She pulls the door shut with a squeal.)

DOCTOR: Are you ready, man?
ROGIN [OC]: Yes.

(Sarah joins the Doctor in the middle of the floor.)

DOCTOR: Switch on now!
ROGIN [OC]: Right!

(The current surges through the door, zapping the Wirrn on the other side.)

DOCTOR: Not bad for a lash up.
SARAH: Has it gone, do you think?

(There is squeaking from the other side of the door.)

DOCTOR: Reporting to the others. They'll know where we are now.
VIRA [OC]: Hello, Doctor? Are you all right down there?
DOCTOR: For the moment.

[Transport ship]

VIRA: You lack confidence?
DOCTOR [OC]: The Wirrn don't give up that easily. They need the Ark. How is it your end?
VIRA: There's been no sign of them in this part of the Ark.

[Cryogenic chamber]

SARAH: Doctor.

(More squeaking outside.)

DOCTOR: I think we've got some more visitors. Don't let the power drop.

(The Doctor and Sarah listen at the door.)

DOCTOR: Gone away.
SARAH: I think so. I can't hear anything now.
DOCTOR: Either discretion is the better part of valour, or
SARAH: Or what?
DOCTOR: Or they're planning something.
SARAH: Yes, but we're safe here, aren't we?
DOCTOR: Unless they chew through the floor. I've left a free-running cable just in case. The insulation should stand up to it.

(An insect arm reaches through the grille and wraps around Sarah's legs.)

SARAH: Oh! Doctor!

(The Doctor grabs Sarah and pulls her back. Then he grabs his free cable and jabs it at the Wirrn's head. There is a flash, then it retreats.)

DOCTOR: Cheer up, we're still on our feet.
SARAH: Those things are so venomous. They'll never give up.
DOCTOR: No, and neither shall we, Sarah. What we're protecting here is too precious.

(In the control room, a Wirrn turns the systems back on.)

SARAH: Why have they turned the power back on?
DOCTOR: We'll find out soon enough.
WIRRN [OC]: Vira, can you hear me?
DOCTOR: She can hear you. What do you want, Noah?
WIRRN [OC]: Your resistance is useless. We control the Ark.
DOCTOR [OC]: And we control the cryogenic chamber. I repeat, what do you want?

[Control room]

WIRRN: We offer you safe passage from the Ark. Surrender now and your lives will be spared.
DOCTOR [OC]: Not a chance.
WIRRN: What does Vira say?
DOCTOR [OC]: She agrees with me

[Transport ship]

DOCTOR [OC]: Don't you, Vira.
WIRRN [OC]: Let Vira speak. She is the Commander.
DOCTOR [OC]: She's busy, resuscitating more humans.

[Cryogenic chamber]

WIRRN [OC]: You lie!
DOCTOR: Listen, Noah. Now hear me. You're beaten. The Ark is of no value to you without its humans, so why don't you just leave us in peace?

[Control room]

WIRRN: Humans require two mass pounds of oxygen a day to stay alive, Doctor. We Wirrn can live for years without fresh oxygen. If you refuse to surrender, we shall shut down the oxygen pumps.

[Cryogenic chamber]

DOCTOR: And if we surrender?
WIRRN [OC]: I have said. You will be allowed to leave the Ark.
DOCTOR: The Wirrn hate all humans. Once we step outside this chamber we'd be attacked.

[Control room]

WIRRN: I am the swarm leader. I guarantee your safety. The Wirrn will spare your lives, but leave the sleepers for us!

[Cryogenic chamber]

DOCTOR: Noah, listen to me. If there's any part of you that's still human, if you've any memory of the man you once were, leave the Ark. Lead the swarm into space.

[Control room]

DOCTOR [OC]: That's where the Wirrn belong, Noah. Not on Earth, not where you were born. Remember the wind and the sun, the fields, the blue sky? That's Earth, Noah. It's for the human race. Don't abandon it.
WIRRN: I have no memory of the Earth.

[Transport ship]

HARRY: I say, Rogin, I don't want to be an alarmist, but I think I saw something moving.
ROGIN: You're right. They're coming up the funnel. Commander.
VIRA: Start starboard four.
ROGIN: Starboard four running.
VIRA: Negative thrust out.
ROGIN: Neg thrust out.
VIRA: Full boost.
ROGIN: Full boost. And check.

(On the monitor, exhaust smoke swamps the Wirrn.)

VIRA: Close boost.
ROGIN: Close boost.
VIRA: Close starboard four.
ROGIN: And close starboard four.

(On the monitor, the ladder is clear.)

HARRY: I bet that singed their whiskers for them.
ROGIN: They won't try that again.
VIRA: I wonder if Noah
ROGIN: Noah?
VIRA: Not important.
DOCTOR [OC]: Are you all right over there?
HARRY: Ahoy there, Doctor. Yes, we're fine, thanks.
DOCTOR [OC]: We heard a rocket engine.
HARRY: Oh, just a warning blast. How are things with you?

[Cryogenic chamber]

DOCTOR: All right at the moment.
HARRY [OC]: Good.
DOCTOR: Keep in touch.
SARAH: I don't know if its my imagination, but it seems to be getting stuffy in here.
DOCTOR: Hmm? It's your imagination.
SARAH: You'd say that anyway.

[Transport ship]

(On the monitor, a swarm of Wirrn are clambering over the outside of the Ark.)

VIRA: They're coming in through the reversion vents!
ROGIN: Look at them. There's a whole army of them out there.
VIRA: Doctor, the Wirrn have space walked round the Ark and have broken into our cargo hold.

[Cryogenic chamber]

DOCTOR: How many of them are there, Vira?
VIRA [OC]: We cannot say, but it looks as though the entire swarm is attacking.
DOCTOR: How long will it take them to reach your control deck?
VIRA [OC]: A few minutes only. The interior bulkheads have a low stress factor.
DOCTOR: Tell Rogin to cut the power. We're coming out.

[Transport ship]

ROGIN: Power off, Doctor.
DOCTOR [OC]: Good. Set the controls on automatic take off and evacuate the ship. Hurry!
VIRA: We'll do as you say, Doctor.

[Transom]

DOCTOR: Come on, Sarah. Come on! Run! Run!

(They run clockwise.)

[Transport ship]

HARRY: It's absolutely crawling with the brutes.
ROGIN: Are you coming or staying?

(Rogin throws the final switches and leaves.)

[Under the transport ship]

DOCTOR: Into the Ark, fast as you can! You too, Sarah! Harry, you go with the girls.

(Rogin closes up the access ladder.)

DOCTOR: Rogin, help me with the synestic locks.
ROGIN: I thought that was your idea.
HARRY: What are you going to do, Doctor?
DOCTOR: Just look after Sarah, Harry.

(The Doctor pulls a module from a strut under the ship.)

DOCTOR: Just leave this to me.
ROGIN: You know what'll happen when you cut that lock?
DOCTOR: There's no point in both of us being killed by the blast. Get into the Ark, man.
ROGIN: You don't want trouble with the space technician's union, Doctor.
DOCTOR: What?

(Rogin knocks the Doctor out.)

ROGIN: That's my job.

(On the ship, the Wirrn watch Rogin pull the module from the last strut just as the engines fire. The transport ship lifts off from the Ark and flies away.)

[Control room]

VIRA: They must have both died instantly.

(Sarah shakes her head.)

HARRY: Come on, Sarah. He'd have wanted you to be brave.
VIRA: Doctor! Where's Rogin?
DOCTOR: Rogin's dead. I woke up in a protection hatch.
SARAH: Oh, Doctor, you're safe.
DOCTOR: Yes, we're all safe now, Sarah, thanks to Rogin's bravery. And perhaps something else.
VIRA: Something else?
DOCTOR: Yes, some vestige of human spirit. Was Noah on our side and one step ahead of us at the end?
VIRA: You mean by leading the swarm into the shuttle?

(The console beeps.)

HARRY: Look.
VIRA: Space Station Nerva.
WIRRN [OC]: Goodbye, Vira.

(The shuttle goes KaBOOM!)

SARAH: The shuttle's blown up!
VIRA: He must have known that that would happen. Noah deliberately neglected to set the rocket stabilisers.
DOCTOR: More than a vestige of human spirit. It can all begin now, Vira. Mankind is safe.
VIRA: I must get my people back to Earth. Now that I've lost the transport ship, I shall have to rely on the matter transmitter.
DOCTOR: Yes.
VIRA: It'll be a long operation. It can only convey three people at a time.
DOCTOR: Yes, it could if it was functioning properly. The signal's faulty. Probably the diode receptors. I'll just beam down and check them.
SARAH: To Earth?
DOCTOR: Yes, that's where the trouble is. Here, fetch me a coat from the TARDIS, will you? You never know what the solar flares have done to the weather.

(The Doctor gives Sarah the TARDIS key, and she and Harry go into the next room.)

VIRA: It isn't anything serious?
DOCTOR: What? Probably no more than a spot of corrosion. Whatever it is, it shouldn't take long to fix, and it'll give me a chance to see if the planet is fully viable again. What's keeping them? Sarah!
SARAH [OC]: Coming!

(Sarah enters in weatherproof trousers. Harry has put on a duffel coat.)

SARAH: Here's your coat.

(They all get into the transmat alcove.)

DOCTOR: I don't remember inviting you two.
SARAH: Er, no, you didn't. But here we are.
HARRY: Well, the Brigadier did tell me to stick with you, Doctor, and orders is orders.
DOCTOR: I hope you don't mind being left.
VIRA: Well, I won't be alone for long. Life is returning to the Ark, and soon to the world.
DOCTOR: Have a jelly baby, Vira.

(He throws her the bag.)

VIRA: Oh, thank you.

(The Doctor, Harry and Sarah vanish.)

VIRA: Thank you.

Transcript originally provided by Chrissie. Adapted by TARDIS.guide. The transcripts are for educational and entertainment purposes only. All other copyrights property of their respective holders.