(Two white spacecraft are chasing a red one, and firing on it. When they hit it and it tumbles towards a planet, they veer off. It crashes in the New Mexico Desert on June 13, 1947, thirty five miles from Roswell, just off Interstate 25.)

[Sammy's Pitstop]

(Dry Springs Nevada, 11 years later. The waitress is pouring a cup of coffee for the young man sitting at the counter, and the Everly Brothers 'Dream' is playing on the jukebox when a man in a slightly tight suit enters.)
DOCTOR: Howdy there, pardners.
JIMMY: Howdy.
CASSIE: How you doing?
DOCTOR: Ah, the smell of fast food on the desert air. The perfume of America.
CASSIE: Hey, are you British or something?
DOCTOR: Something, that's me, definitely. I was passing and I got the fancies. A bowl of chili. The sort you only ever got in an American diner before 1962. I'm the Doctor, by the way.
CASSIE: I'm Cassie. This is Jimmy Stalkingwolf.
DOCTOR: Whoa, where did you get that?
(In a case on the counter is a green coil with metal ends.)
CASSIE: It's supposed to be from the saucer that crashed five years back. You know, like that Roswell thing over in New Mexico. My mom, she used to run this place, thought it would bring in the tourists.
(The Doctor has taken the coil out of its box. He zaps it with his sonic screwdriver.)
CASSIE: Like they don't know a piece of junk when they see it.)
(The coil lights up and the light bulbs in the ceiling blow.)
DOCTOR: Ooo. Sorry.
JIMMY: What did you just do, man?
DOCTOR: I'm afraid this isn't quite a piece of junk.
(A car stops outside.)

[Car]

(Two men in black are in it. The blond one looks at a device he is holding.)
DREAD: It has been activated.

[Sammy's Pitstop]

CASSIE: Are you saying this really did come from a flying saucer?
DOCTOR: Well, a flying saucer, maybe. They were quite fashionable in the fifties. Bit like bobbie sox and haircream.
JIMMY: I told you. I told you there was something going on round here.
DOCTOR: What do you mean?
CASSIE: Jimmy works out at the Broken K ranch. Says there's this space monster eating the cattle. I told him it's a cougar.
JIMMY: No cougar did what I saw, or left those tracks.
(One of the men in black enters.)
DOCTOR: Oh, hello.
DREAD: I'll take the ionic fusion bar.
CASSIE: Come again?
DOCTOR: He means your piece of junk.
CASSIE: No way! It doesn't belong to you.
DOCTOR: Not such a good idea to argue. Hello, I'm the Doctor.
DREAD: Give it to me.
JIMMY: Didn't you hear what the lady said?
(Jimmy puts his hand on the man's shoulder.)
DOCTOR: That's definitely not a good idea.
(One gentle shove sends Jimmy flying backwards down the length of the diner.)
DOCTOR: Okay, time to go.
(The Doctor sonicks the radio as they run out. It sparks and glows, making the man cower. They all drive off in Jimmy's pickup truck.)

[Jimmy's pickup]

DOCTOR: Now, what was that about a monster?
(The blond man's eye's glow green.)

[Broken K Ranch]

(They are by a very large footprint in the sand.)
JIMMY: What kind of cougar makes a print like that?
DOCTOR: No cougar.
(Cassie and Jimmy turn to look at what is suddenly covering them with its shadow. The Doctor is oblivious.)
DOCTOR: No animal. This was something big. Very big. Something powerful. Something that isn't from around here.
(Like the big green red-eyed being towering over them. It roars.)
DOCTOR: Ah! Viperox battle drone. Hello!
(Cassie screams.)
DOCTOR: Try not to do that. Apart from being one of the most vicious killers in the cosmos, Viperox have very sensitive ears.
(Jimmy puts his hand over Cassie's mouth.)
DOCTOR: Thank you. Not a good idea to aggravate him.
JIMMY: It doesn't look aggravated to me, Doc. He looks hungry.
DOCTOR: Doctor, not Doc, and if he was hungry he'd be picking bits of cowboy boots and bobbie sox off his mandibles by now.
CASSIE: So if he ain't going to eat us, what is he going to do?
DOCTOR: It's a Viperox battle drone. What it doesn't use for food it uses for target practice.
(The Viperox raises its very long 'arms' and opens its claws. There are harpoons inside them.)
DOCTOR: Look out!
(A harpoon flies over their heads and explodes in the distance.)
DOCTOR: Run! Back to the pickup!
(A helicopter arrives overhead.)
DOCTOR: Get down!
(As they hit the ground, a missile from the helicopter makes the Viperox go Splat! A claw lands in the ground close to them. The helicopter lands and they dust themselves off.)
DOCTOR: Howdy! Perfect timing.
SOLDIER: Our orders are to take you with us.
DOCTOR: Whose orders are those, then?
SOLDIER 2: Colonel Stark, sir.
DOCTOR: Colonel Stark! Who's that, then.
SOLDIER 2: Commanding Officer, Operation Fallen Angel, Groom Lake Army Airbase.
DOCTOR: What? You mean Area 51. Dreamland? Oh, I've always wanted to go there.
CASSIE: Doctor, no. People that go there, civilians, they never come back.
JIMMY: I've heard all kinds of things about that place, and none of it's good. It's said they've got aliens there from the Roswell crash.
DOCTOR: I know. I've always wanted to take a peek. Take me to your leader. Allons-y.

DOCTOR [OC]: Dreamland. The United State's most secret base. It doesn't appear on any map, and the government won't admit it exists till 1994.
JIMMY [OC]: What did you say?
DOCTOR [OC]: Er, never mind.

[Elevator]

CASSIE: Where are they taking us?
DOCTOR: I don't know, but I don't think Colonel Stark has a penthouse apartment.
(They go down.)

[Secure room]

(With a submarine style door, two filing cabinets, two chairs and a table.)
JIMMY: So what happens now?
CASSIE: Nothing good.
DOCTOR: Oh, come on. I thought the fifties were supposed to be a time for optimism. I mean, you thing you're going to have flying cars in another ten years.
CASSIE: Yeah, sure, if the Reds don't nuke us first.
DOCTOR: The Reds? Manchester United? Oh, the Russians. Soviet Union. I wouldn't worry about them. They're as scared of a nuclear war as you are.
(The door opens.)
STARK: I hear you people had some trouble.
DOCTOR: Ah, Colonel Stark, I presume. Hello, I'm the Doctor, (sotto) and I think you may have a serious infestation problem.
STARK: We have the situation in hand.
CASSIE: So what are you going to do about it?
STARK: You don't have to worry, ma'am.
DOCTOR: Oh? Why's that?
STARK: Because you're going to forget everything you've seen. You're going to forget everything.
DOCTOR: No, Colonel. Colonel, you're making a mistake.
STARK: Soldiers! Take them to the lab. Prepare them for the mind wipe.

[Mind wipe lab]

(A large place. The Doctor, Jimmy and Cassie are fastened to three tables tilted slightly backwards.)
CASSIE: What are they going to do to us?
DOCTOR: From the look of this chamber, use some sort of amnesia gas.
JIMMY: So we forget everything about that Viperox bug thing? Maybe that isn't so bad.
DOCTOR: Hmm. Trouble is, no one really perfects a targeted amnesia drug for another fifty years. The sort of thing Colonel Stark has in his medicine cabinet won't just wipe out the last few hours. You'll forget everything.
CASSIE: They can't do this. We're US citizens.
JIMMY: Yeah, Cassie, and they're the Army. They can do whatever they want. They've been doing it ever since the Bear River massacre.
(Stark enters.)
DOCTOR: Colonel. Sorry I can't salute, but I seem to be strapped to a table.
STARK: The gas can have side-effects. The straps are for your own safety.
DOCTOR: Very thoughtful, but have you considered that you've got dangerous ten foot tall aliens out in the desert? And believe me, Colonel, where there's one Viperox there's at least a thousand more.
STARK: You know a great deal, Doctor. More than is good for you. But I'm going to fix that.
(The Colonel turns a red wheel and green gas starts to enter the room.)
CASSIE: You can't do this. So help me, I'm going to tell the President.
STARK: Little lady, in ten minutes you won't know who the President is. You won't know who you are.
(Stark leaves, closing the door behind him.)
DOCTOR: Try to hold your breath. I just need a few more seconds.
(A big screen in front of them shows a hypnotic image. The Doctor gets one arm free.)
JIMMY: How did you do that?
DOCTOR: Little trick I learned off Houdini.
(He frees himself and shuts off the gas.)
CASSIE: Great, but we're still trapped.
(The Doctor points to a grille in the ceiling.)

[Ventilation shaft]

DOCTOR: There's always a ventilation shaft.
CASSIE: Doctor, are you sure there's a way out of here?
DOCTOR: Of course there's a way out. There always is. Apart from in Star Wars, of course.
JIMMY: Hey, Doc, are you ever going to start making sense?
DOCTOR: Are you going to stop calling me Doc? I'm the Doctor, all right? And you're not Bugs Bunny.
JIMMY: Hey.

[Corridor]

(The Doctor punches out a grill in the base of the shaft and drops down. Cassie follows.)
CASSIE: Where are we?
DOCTOR: Who am I, the Dreamland tour guide? Come on.
JIMMY: Why are we going that way? I mean, who gave you the stripes? You're not even American.
DOCTOR: Well, come to that, I'm not even human.
(An alarm sounds.)
DOCTOR: But someone's just noticed we've escaped, so whichever way you're running, I'd start now.
(They follow the Doctor to a junction. Armed soldiers are approaching.)
CASSIE: What now?
(The Doctor spots a sign - Lab 51.)
DOCTOR: That way.
JIMMY: There's no way through here.
(The Doctor sonicks the lock on the door to Level 24B.)
DOCTOR: Come on.
(The soldiers run past.)

[Lab 51]

(One wall has a big metal door on it, labelled Warning Biohazard. A movie camera is pointing at it.)
CASSIE: Did you mean what you said back there, you're not human?
DOCTOR: Well, human, Time Lord, it's all just an accident of dimensional geography when you get down to it. I wonder what's behind there?
(He pushes the button that raises the metal door. A small grey alien is sitting on the bed in an otherwise empty cell. It raises its large head and blinks its big black eyes.)
DOCTOR: Ah.
JIMMY: Uh, now that is an alien.
DOCTOR: The question is, why are they keeping her a prisoner?
(Soldiers burst in. The Doctor sonicks some computer equipment which shatters, injuring the soldiers.)
DOCTOR: Quickly, this way.
(Into the elevator.)
DOCTOR: Hold on.
(He sonicks the controls and up they go.)

[Elevator]

CASSIE: What if there are more soldiers waiting for us up top?
DOCTOR: Charm offensive.
JIMMY: What's that mean?

[Hangar]

(They are surrounded by the sound of rifles being cocked.)
DOCTOR: It means you put your hands up and smile.

[Stark's office]

(There is a Viperox in the shadows.)
AZLOK: You have a problem, Colonel?
STARK: Nothing we can't handle.
AZLOK: I warn you, Colonel, Fail me, and your world will pay the price.
(The Colonel speaks into his walkie-talkie.)
STARK: Don't let them get away again. And you, keep your soldiers off the plains, Lord Azlok. I don't need this getting any more complicated.
AZLOK: Viperox are not accustomed to taking orders from lesser species, Colonel, or to their mistakes. See to it that you do not let us down.

[Hangar]

(Our trio are walking towards an alien spacecraft.)
JIMMY: I cannot be seeing that.
CASSIE: A real live flying saucer.
DOCTOR: Yeah. Fancy taking her for a spin?
(The Doctor sonicks the ship and the entry ramp drops down.)
DOCTOR: Okay, come on!
SOLDIER: Stop, or we fire!
SOLDIER 2: Don't shoot, you'll hit the ship.
(The Doctor, Jimmy and Cassie get aboard, the ramp closes up and)
SOLDER 2: Fall back! Fall back!
(The spaceship takes off, smashing its way out of the hangar and up into the sky.)

[Spaceship]

(The Doctor is at the controls, and the flight is not exactly smooth.)
CASSIE: Can you really fly this?
DOCTOR: Well, sort of. Ooff. Stark's scientists have retro-engineered it, probably based on their prisoner's ship. They've got a couple of systems the wrong way round, but we're getting there. Ha, ha, ha! Left is right and up is down. No problem, no problem.
(Then sparks fly.)
JIMMY: What did you do that time?
DOCTOR: Wasn't me.
(The US Air force is shooting at them.)
DOCTOR: We've got company. Hang on!
CASSIE: Those red lights don't look good.
DOCTOR: Red lights never are. I wonder if parachutes came as standard or an added option.
(Smoke trailing from the engines, they crash into the desert.)
PILOT [OC]: Target has crash-landed.
STARK [OC]: Return to base.

[Stark's office]

STARK: Command? I want a team out there on the double. It's gonna be dark soon, and whoever the Doctor is, I want to know how he can escape in a spaceship the US Army hasn't figured out how to fly yet!
AZLOK: Perhaps this Doctor is more than he appears.

[Solitude]

(The Doctor, Jimmy and Cassie walk into a ghost town at sunset.)
DOCTOR: Solitude. Well, it's certainly quiet and lonely.
JIMMY: It was a mining town a century back. No one here now but the ghosts.

[Saloon]

(They go into a building, and the Doctor takes down an oil lamp.)
CASSIE: Nice place, Jimmy.
DOCTOR: Have you got a match?
JIMMY: Sure. Here.
(They light the lamp.)
CASSIE: Look, what's going on, Doctor? If the military know about these alien things, how come we're the enemy?
DOCTOR: I don't know, but I intend to find out. Tomorrow I'm going back to Dreamland.
JIMMY: What was that?
(He goes into a room with a hole in the floorboards, and gets grabbed by a Viperox.)
JIMMY: Hey! Argh!
DOCTOR: Jimmy!
(Jimmy is dragged underground. The Doctor and Cassie follow.)

[Tunnels]

DOCTOR: Don't make too much noise, Cassie. Remember what I said. The Viperox have a heightened sense of hearing.
CASSIE: Is Jimmy going to be all right?
DOCTOR: If the Viperox had wanted to kill him, it would have done it back in Solitude.

[Cavern]

(Jimmy is fastened in a carapace, with two Viperox looking at him.)
JIMMY: What are you going to do with me, you big ugly garbage bugs?
(A third Viperox walks up to them.)
AZLOK: Be careful, human. I am Azlok, Lord Might of the Imperial Viperox Warhorde. Consider who seems in more danger of being crushed underfoot.
JIMMY: You're never going to take over Earth. The military will blast you into bug bits.
AZLOK: What do you think the Empire of the Viperox would possibly want with this termite ball?
(The Doctor is listening.)
AZLOK: Who is this man called Doctor?
DOCTOR: Oh, now, that would be me.
(Cassie sneaks behind the Viperox towards Jimmy.)
AZLOK: Ah, Doctor.
DOCTOR: I've got a few things I'd like to ask you, as it happens. The most obvious being, if you're not here to invade it, what on Earth are you doing here?
(Cassie pulls pieces off the carapace off, to free Jimmy.)
AZLOK: You are not of this world. I hear two hearts beating.
DOCTOR: Then note their rhythm. I'm not scared of you. And whatever you're doing on Earth, I won't let you hurt its people.
AZLOK: We seek only an enemy of our kind.
DOCTOR: Oh? And who's that, then?
CASSIE: Doctor, look out!
(Azlok turns, and Cassie throws the oil lamp at him. They run as the flames encircle the Viperox.)

[Tunnels]

DOCTOR: What did you do that for?
CASSIE: It's called escaping, Doctor.
DOCTOR: I was that close to discovering what's going on here.
(Jimmy takes a step back and falls backwards into a depression in the ground.)
JIMMY: Whoa!
DOCTOR: Jimmy?
(The Doctor uses his sonic screwdriver as a torch to reveal a collection of pyramidical pods.)
DOCTOR: Oh, this isn't good.
JIMMY: Doc, tell me this isn't an egg.
DOCTOR: The Viperox never bring an army with them. They land, go underground, and hatch one.
CASSIE: Hatch an army? Then who's laying
DOCTOR: The Viperox Queen.
(And she is massive.)
DOCTOR: I don't think she's amused. I have this effect on royalty. Run!

[Mine tunnel]

(Complete with rails and an ore wagon.)
JIMMY: Must have found our way into an old mine.
CASSIE: They're coming.
DOCTOR: Get in the truck.
(The Doctor sonicks the nails from the support beams, kicks away the block of wood from the wagon wheels then leaps aboard as it heads off down the slope.)
CASSIE: The roof's falling in.
(Right on top of the pursuing Viperox.)
DOCTOR: That should hold them for a while. Now all we have to do is get off.

[Desert]

(They crash through a boarded up adit, and stop when they hit a boulder. They are met by four men in black.)
DREAD: Good morning, Doctor.
DOCTOR: Hello again. I don't think we got properly introduced back at the diner. You are?
DREAD: Mister Dread. These are my associates.
DOCTOR: No, no, let me guess. Mister Fear, Mister Terror and Mister Apprehension. The Alliance of Shades' mop up teams never were all that good at mingling.
CASSIE: You know these guys?
DOCTOR: Sort of. The US government aren't the only people that want to keep a lid on aliens. A lot of planets think you're too primitive.
JIMMY: Primitive? We have nuclear missiles.
DOCTOR: Yes, primitive and aggressive. No offence.
CASSIE: None taken.
DOCTOR: Anyway, if the Alliance get reports of a spaceship crashing or some showoff sort of pilot doing loop the loops over the White House, they send in these guys to dispose of the evidence. And sometimes the eye witnesses. Only they're not very good.
DREAD: Where is the ionic fusion bar?
DOCTOR: Huh? Oh, the gizmo from the crashed spacecraft? Sorry, lost that while we were being attacked by a Viperox battle drone.
DREAD: Where is it?
CASSIE: We haven't got it.
(Dread replaces his hand with a weapon.)
JIMMY: Whoa, am I seeing this?
DOCTOR: Didn't I mention? They're robots.
(All the MiB are aiming weapons at them.)
DREAD: Give it to me.
DOCTOR: Don't you think the Alliance of Shades would be more interested in a thousand Viperox battle drones ready to hatch under our feet than in a piece of space flight hardware?
DREAD: Tell me where the ionic fusion bar is, and we will deal with the Viperox.
DOCTOR: What! You couldn't even keep a lid on flying saucers. You know, in 1972, the Alliance pulls the plug on the lot of you. How are you four going to hold back Lord Azlok and his Viperox hordes? Unless
(Dread tumbles forward, with an arrow in his back. The other robots do the same.)
JIMMY: Grandpa!
DOCTOR: Oh, I could have found out everything then. Why does that keep happening today?
JIMMY: Doctor, Cassie, this is my grandpa, Night Eagle.
CASSIE: Hey, that was kind of handy with those bows and arrows.
DOCTOR: Yes, straight through the central processing unit. One lucky shot I could believe, but four? You've met men like this before, haven't you, Night Eagle.
NIGHT EAGLE: We saw the disc fall from the skies, and thought more had come.
DOCTOR: More of who?

[Cave]

(Night Eagle leads them into a cave high up a cliff face. There on a wooden chair sits another of the small, big-eyed grey aliens.)
DOCTOR: Oh my.
NIGHT EAGLE: Five years ago we saw his ship crash.
CASSIE: So the ionic fusion thing came from his ship?
JIMMY: How could you keep this secret?
NIGHT EAGLE: Others searched for him. Men in black suits. Those who knew swore to tell no one, not even our blood kin, to keep him safe.
DOCTOR: It's all right, I'm the Doctor. I can help you.
RIVESH: I want to go home.
DOCTOR: I can take you home.
RIVESH: Not without Seruba Velak.
JIMMY: Who?
CASSIE: The other grey alien back at Dreamland. Keep up, Jimmy.
DOCTOR: But she wasn't on your ship, was she. Night Eagle and his men would have saved her, too.
RIVESH: No. My name is Rivesh Mantilax. Seruba Velak is my wife. Her ship was attacked by pirates. She was an ambassador of my people. The pirates were paid to ensure she never reached her destination. She transmitted a distress signal, but by then we were at war.
DOCTOR: With the Viperox.
RIVESH: Yes. They had sabotaged the alliance my wife had tried to negotiate against them. The war was long and savage, and I had a duty to my people. But the torture of watching my species slaughtered was nothing to the loss of my wife. When I could, I came for her.
DOCTOR: And let me guess. The military had Seruba Velak. The Roswell crash. So they were already looking for more spaceships, and they shot you down.
RIVESH: Without provocation.
DOCTOR: Forgive them. They're primitive people, and scare easily.
CASSIE: We've seen your wife. She's alive.
RIVESH: Tell me they have not harmed her.
DOCTOR: I think she's all right, and I'm going to get you both home. Or at least to whatever might be left after a war with the Viperox.
STARK: No, I don't think you will, Doctor.
DOCTOR: Colonel Stark.
STARK: On behalf of the United States government, thank you for leading us to this alien. You just helped me save the world.
DOCTOR: For the first time in nine hundred years, why does that feel like bad news?

[Army truck]

CASSIE: I guess they'll try and wipe our memories again.
DOCTOR: You'd think Stark could be more forgiving, as accidentally leading him to Rivesh Mantilax has somehow saved the world, apparently.
NIGHT EAGLE: Men like Stark don't save worlds. All they know is destruction.
DOCTOR: That's what worries me.

[Operations room]

(Section B Level omega security. A big map of the world on one wall and a diorama of the local area on a circular table in the middle.)
DOCTOR: Lord Azlok.
AZLOK: Ah, Doctor.
DOCTOR: What an unexpected displeasure.
CASSIE: What in heck are you doing here?
STARK: Ah, I see you've met my ally, Lord Azlok.
DOCTOR: Colonel, the Viperox savage and decimate every world they encounter. They don't have allies, they kill everything.
AZLOK: But we have a common interest.
(Stark switches on a monitor, showing the video feed from Lab 51.)
DOCTOR: Rivesh Mantilax.

[Lab 51]

(The metal door rises.)
RIVESH: Seruba Velak.
(They are parted by a thick pane of glass.)

[Operations room]

AZLOK: Did he tell you who he was, Doctor?
(Azlok steps towards Cassie, and Jimmy gets between them.)
STARK: He's a scientist. A specialist in genetic warfare. You know what that is?
DOCTOR: Yes. Not pleasant.
AZLOK: Rivesh Mantilax had developed a weapon genetically targeted at the Viperox, to wipe us from the universe.
JIMMY: Doesn't sound like such a bad thing.
DOCTOR: No, Jimmy, it is. A very bad thing. Who's to say one day even the Viperox won't discover a better way to exist.
CASSIE: But I don't get it, Colonel. Why are you in cahoots with the Viperox?
(Stark lights up part of the world map - USSR.)
STARK: The weapon can be modified to wipe out our enemies instead.
DOCTOR: You mean Russia?
STARK: The Reds are sitting on a thousand nukes, and everyone of them has Uncle Sam's name on it.
NIGHT EAGLE: The Russians will never fire them. They know as well as you that would be the end of the world.
DOCTOR: Does President Eisenhower know about this plan?
STARK: Heck, the President doesn't even know aliens exist.
DOCTOR: Well, anyway, it's irrelevant, as you don't have the weapon, do you, Colonel.
(Enter Dread, sparking occasionally.)
JIMMY: Hey, I thought he blew a gasket.
DOCTOR: Oh, that's the trouble with robots. You can never be sure you've shut them down. Twist a few wires together and they're anybody's, isn't that right, Lord Azlok?
DREAD: I retrieved the ionic fusion bar.
DOCTOR: Except it's not an ionic fusion bar, is it. I've worked that much out. Why would the Alliance of Shades have been more interested in ignition systems than a Viperox horde?
CASSIE: Because it's really a weapon?
DOCTOR: Cleverly disguise to fool even me. And a weapon that could kill billions throughout the universe. And now you expect Rivesh Mantilax to reprogram it to wipe out the whole of Russia?
AZLOK: It is the only way to make my kind safe, and he will do it.
DOCTOR: Only if you still have the weapon.
(The Doctor sonicks Dread, grabs the bar and runs for the door.)
STARK: Doctor!
(Stark chases after him.)

[Rooftop]

(The Doctor runs out onto the flat roof of the building. Two helicopters rise up, then he turns to face Stark.)
STARK: There's nowhere to go.
DOCTOR: I'm not going to let you do this, Stark. If you trigger this weapon you will kill millions of innocent people.
STARK: You're talking like a Red.
DOCTOR: Listen to me, Colonel. You cannot trust Lord Azlok. There's a Viperox Queen giving birth to an army out there. Once this weapon is reprogrammed, there is nothing to stop them attacking Earth.
STARK: A bunch of supersized cockroaches against tanks and bombers? I'd like to see them try it.
DOCTOR: Ask Rivesh Mantilax and Seruba Velak. Their technology is a thousand years of Earth. They couldn't stop the Viperox. How will you? Who are you going to be, Colonel? The man who saves the world, or the one who destroys it.
(The Colonel thinks for a few moments, then lowers his gun and speaks into his walkie-talkie.)
STARK: This is Colonel Stark. Pull back.
(The helicopters leave.)
DOCTOR: You're doing the right thing.
STARK: Soldiers, put Lord Azlok under arrest.
SOLDIER [OC]: He's gone, sir.
DOCTOR: Ah. Two problems with the Viperox, Colonel. You can't trust them, and they have very good hearing.
(Azlok bursts through the door onto the roof.)
STARK: Consider yourself a prisoner of the United States Army.
AZLOK: We have laid waste to entire galaxies. The United States and Earth itself will be as dust beneath our feet.
DOCTOR: Not if I can help it. Take my advice and go home, while you still can.
AZLOK: Because you have the genetic weapon? Without Rivesh Mantilax it is useless.
(Four wings pop out from under Azlok's carapace and he flies up into the air.)
AZLOK: Now we shall tear your world to shreds!

[Lab 51]

(Cassie is cradling Rivesh in her arms when the Doctor bursts in.)
CASSIE: Azlok took out the guards when you escaped. He attacked him before we could do anything.
DOCTOR: And there's nothing I can do.
(Seruba hammers on the glass.)
DOCTOR: Stand back.
(He sonicks it to smithereens and she runs out.)
SERUBA: My husband.
(Stark enters.)
STARK: Can we activate the weapon without him?
DOCTOR: Oh, you're all heart, aren't you, Colonel. No, it's attuned to his DNA. That's why Lord Azlok needed him to reprogram it. Or, better still, needed him dead.
SERUBA: He's not yet passed. I can save him! I need to get to the remains of my ship.
STARK: The wreckage is stored in the vault. It's impossible.
DOCTOR: You'd better have a good reason why.
STARK: Operation Fallen Angel is set up to examine classify and detain all alien life that crashes on Earth. Something got loose in there.

[Cavern]

AZLOK: Majesty, I need warriors. Tonight we swarm.

[Outside the vault]

(Another mine entrance in a rock face. The big steel doors are marked USAF.)
DOCTOR: The Viperox won't attack until sundown. We've got an hour, tops.
STARK: I've got men laying charges in the old mine. If we don't kill them, we'll bury them down there.
DOCTOR: And they'll just dig themselves out again. I need that weapon to deal with the Viperox. I need Rivesh Mantilax, and I need to go into that vault.
JIMMY: We're coming with you.
DOCTOR: No. I've got another job for you two.

[Vault]

(The Doctor and Seruba walk between the three or four metre thick doors of the vault, which roll closed behind them. The place is stacked high with large crates.)
DOCTOR: This is going to take a while.

[Jimmy's pickup]

(Jimmy and Cassie are driving through the desert.)
JIMMY: What sort of big blue box is he going to leave on the corner of Main Street?
(They turn onto the road into Dry Springs.)

[Vault]

DOCTOR: I hope we find whatever it is we're looking for in time, Seruba Velak.
SERUBA: And then you will use the genetic weapon to destroy the Viperox, to scour them from the cosmos.
DOCTOR: Well, it's not that simple. Shush. Did you hear that?

[Dry Springs]

(The blue box is parked across the street from Sammy's Pitstop.)
JIMMY: What in tarnation is it?
CASSIE: I don't know, but look, it's almost sunset.

[Vault]

(The Doctor gives Seruba his torch.)
DOCTOR: Here, keep looking. We have to save your husband. I'm going to see what's out there.
(He lights up his sonic screwdriver. In the desert, claws jab their way up through the sand. Somehow, the Tardis has been loaded onto the back of the pickup. The Viperox are coming along the street, burning buildings as they go.
In the vault, something swoops down towards the Doctor. He turns and sees a glowing creature.)
DOCTOR: Oh dear.
SERUBA: Doctor, I've found it.
DOCTOR: Unfortunately, so have I.
SERUBA: What is that?
DOCTOR: They are Skorpius flies. A billion of them. A giant swarming brain.
SERUBA: If it's a brain, we can communicate.
DOCTOR: Yeah, but the Skorpius swarm brain only has one thing on its mind.
SERUBA: Which is?
DOCTOR: Well, at this time of day, supper. Run!
(The Doctor spots an open crate.)
DOCTOR: Quickly, (unintelligible).

[Crate]

SERUBA: This is your plan?
DOCTOR: It's in development.

[Operations room]

SOLDIER: We're getting reports of Viperox within a ten mile radius of the old Solitude mine.
(A row of tanks start shelling the creatures, so they take to the air.)

[Crate]

SERUBA: In your plan to escape like a snail, how do we see where we're going?
DOCTOR: Who needs to see? Didn't you count your steps on the way in? Eighty four steps ahead, turn left a hundred and two steps, turn right sixty two steps and we're out the door.
(He sonicks the bolts out of the bottom of the crate.)
DOCTOR: Always count your steps, Seruba Velak. You never know when you might need to escape in a box.

[Jimmy's pickup]

(Speeding along the road with Viperox in pursuit.)
CASSIE: The whole town, they just tore it apart.
JIMMY: We've got to concentrate on getting this box back to the Doc without running into any more bugs.
(They swerve around Viperox breaking through the tarmac, then head off into the desert as two more shoot at them.)

[Operations room]

(A soldier relays reports.)
SOLDIER: Wiped out Dry Springs.
(Then the helicopter flight are descended upon by flying Viperox.)

[Outside the vault]

DOCTOR: Remember, Seruba Velak, some men are born great, others have crates thrust upon them. Come on, we've got a planet to save.
(They drive off in a jeep which has been kindly left by the vault entrance.)

[Jeep]

(They skid to a halt at the sight of Groom Lake Army Airbase being lit up by explosions.)
DOCTOR: That doesn't look good. That doesn't look good at all.
SERUBA: The base, we'll never get in there.
DOCTOR: We have to, or Earth is finished.

[Corridor]

(The Viperox break in.)
SOLDIER: Fall back!

[Operations room]

SOLDIER: They've taken all but the lowest levels, sir.
(Then the Viperox break in here, too.)
AZLOK: Colonel Stark. So pleasant to see you again.
(More Viperox smash through the rear wall. Stark's pistol is knocked out of his hand.)

[Jeep]

SERUBA: The soldiers cannot stop the Viperox. Nothing can.
DOCTOR: Oh, no? Just watch me.
(Jimmy's pickup skids to a halt beside them.)

[Operations room]

AZLOK: Tell me where the weapon is. It is useless to you with Rivesh Mantilax dead.
STARK: Go to hell, you overfed roach.
AZLOK: Unless, of course, Rivesh Mantilax survives.

[Desert]

(The Tardis has been unloaded from the pickup.)
CASSIE: So what's the big deal with the blue box?
DOCTOR: Take a look.

[Tardis]

JIMMY: Holy smokes.

[Lab 51]

(The Tardis materialises, startling the soldiers guarding Rivesh.)
DOCTOR: At ease. Seruba Velak, do your stuff.
SERUBA: O my husband.
(She places a glowing ball on his head. The room fills with light then it vanishes. Rivesh wakes.)
RIVESH: Seruba Velak.
DOCTOR: Sorry, but we don't have much time. The Viperox will be coming through that door any minute. I need you to activate the genetic device.
RIVESH: Happily. They destroyed our world. Now to wipe them from the face of creation.
DOCTOR: No, we can't do that. I won't allow it.
JIMMY: We've got to blow these monsters to hell.
DOCTOR: This weapon will destroy the Viperox not just on Earth but across the universe. No one has the right to destroy an entire species.
CASSIE: Doctor, they destroyed my town.
DOCTOR: Please, trust me.
RIVESH: You brought my wife and me back together. I trust you.
JIMMY: They're almost here.
(Rivesh compresses the spring inside the bar, and releases it. It is now glowing.)
DOCTOR: Thank you.
(He sonicks it, then Azlok drops in through the ceiling. The Doctor runs into the Tardis and pulls a cable from underneath the console.)

[Tardis]

AZLOK: Trigger the device, and he dies.
(Azlok has Jimmy by the neck.)
DOCTOR: I'm not going to destroy the Viperox horde. Believe me, I can't.
AZLOK: Because you are weak.
DOCTOR: Because you're an evolving species. One day, something incredible is going to happen. You will change, become peace-loving.
AZLOK: This is madness.
DOCTOR: And this, Lord Azlok, is my ship. She might have a few trillion light years on the clock, the chameleon circuit doesn't work and the temporal sat-nav is always on the blink, but, do you know what? She had got the meanest sound system in the universe.
(The Doctor plugs the weapon into the console and an ear-splitting sound is broadcast. Azlok retreats in pain, letting Jimmy go.)

[Operations room]

(The other Viperox dig a hole in the floor to escape through.)
DOCTOR: Go back to Viperon, and don't even think about coming back.
AZLOK: Your day will come, Doctor.
DOCTOR: Yeah, so they say.
(The Viperox all retreat. Out near the Solitude mine, a spaceship rises up through the ground and heads off into space.)

[Groom Lake Army Airbase]

(The Doctor hands the weapon to Stark.)
DOCTOR: There you go, Colonel. Put that somewhere safe. You won't have any more infestation problems.
STARK: Are you sure?
DOCTOR: I tweaked the weapon to attack the Viperox' nervous system on an ultrasonic level. Nothing deadly, just really annoying. The Tardis was just a big amplifier. But this'll do the trick for you now. Keep the bugs out of the house by a light year, or your money back.
STARK: On behalf of the United States government, Doctor, thank you.
DOCTOR: No, no, don't.
(Stark salutes him.)
DOCTOR: Yeah, well, like I said, the Viperox are going to change their ways. I hope you do, too, Colonel Stark. The Russians are nice people, and so are some aliens.
(Rivesh and Seruba walk up into their spaceship and fly away.)
DOCTOR: It doesn't look too bad with the dints knocked out, does it?
STARK: I guess I'm going to have to trust you people to keep quiet.
CASSIE: Oh, what's up, the Viperox smash up your mind-wipe chamber?
(Stark walks away.)
JIMMY: What about you, Doc? What now?
DOCTOR: Well, I never did get anything to eat. I think I'll grab a takeaway. Chinese, Ming Dynasty. Best dim sum this side of infinity.
CASSIE: If you ever get the taste for chili again
DOCTOR: It's a date. Meanwhile, Jimmy, Cassie might need some help cleaning up after the Viperox hit town. Why don't you give her a hand?
JIMMY: She's got it.
(Jimmy holds Cassie's hand, and the Tardis dematerialises.)