(A frightened bearded man is making a telephone call.)
ROSCOE: Police, please. Hello? Yes. I know who did it. Who did it all. I figured it out. No. No, I can't speak up. They might hear me.
(Something hisses or sizzles nearby.)
ROSCOE: Oh, no. Oh, no. Listen. Listen. They are everywhere. All around. We've been so blind. Argh!
(In a flash he is pulled downwards and disappears, and the telephone dangles on its cord from the wall.)
OPERATOR [on phone]: Hello? Sir? Are you in a safe place? Are you being held against your will? Sir?
(Our attention is brought to a image of an elongated screaming bearded man forming on the narrow wall paper border running across the middle of the wall.)

[Tardis]

(Clara comes up the stairs to the console room.)
DOCTOR: You could leave all that stuff here, you know. We do have literally acres of room.
CLARA: Oh, no. It's all right. Danny's got a little bit territorial. The idea of me leaving so much as a toothbrush here. But, still, he's all right with us doing this which I admit's a little bit weird, cos you'd think if he had a problem with me leaving stuff in the Tardis, he'd object to me travelling in the Tardis. But he's not, so.
DOCTOR: Sorry. Stopped listening a while ago. Okay. Er, same time you left, same place-ish.
CLARA: Ish? Don't give me an ish.
DOCTOR: These readings are very er, ishy.
CLARA: Er, Doctor?
DOCTOR: Uh huh?
(He goes to join her looking at the Tardis door, which is now about a metre high. The Doctor stoops to open it and look outside.)

[Waste ground]

(The sound of a train travelling along a track nearly. Doctor struggles to squeeze out through the gap. Clara follows him and closes the door. Why didn't they open both doors? There are tracks and a train shed behind them. A sign on the railings says Bristol Sidings 344.)
DOCTOR: Well. Well, I wonder what caused this? I don't think we're bigger, are we?
(He scans Clara.)
CLARA: Bristol? Doctor, we're in Bristol!
DOCTOR: And a hundred and twenty miles from where we should be. Impressive.
CLARA: No. Not impressive. Annoying.
DOCTOR: No. This is impressive.
(He points at Clara.)
DOCTOR: This is annoying. The Tardis never does this. This is huge! Well, not literally huge. Slightly smaller than usual. Which is huge.
CLARA: Yes. I get it. You're excited. When can I go home?
DOCTOR: Your house isn't going anywhere. And neither is mine until I get this figured out. Could you not just let me enjoy this moment of not knowing something? I mean, it happens so rarely. Look, I don't think this is dangerous, but I wouldn't like you to get squished accidentally. Anyway, I need you to help me find out what's caused this.
CLARA: Fine. I'll go take a look around.
(Clara walks away past the train shed whilst the Doctor squeezes back in through the Tardis door.)

[Shopping precinct]

(A older man wearing an ID badge goes up to a younger black man in a yellow luminous waistcoat, standing in front of a wall full of graffiti tags. There are other men there. All have numbers on their shirt collars.)
FENTON: It's your filth, Rigsy, start with your signature.
(Fenton puts a brush into a tin on white paint. A bald man with number 36 on his collar speaks up for the young man.)
AL: Oh, come on, there's no need for this.
(Rigsy, number 52, takes the brush.)
FENTON: There you go.
(Rigsy starts to paint over his tag.)
FENTON: Get on with it. This is community service, not a holiday camp.

[Tardis]

(The Doctor is closely examining a Tardis circuit when there is a jolt and an an alarm sounds.)
DOCTOR: Now, that wasn't me, was it?
(He goes to the door and looks at it.)
DOCTOR: Oh, that can't be good.

[Underpass]

(Clara goes down towards an underpass. There is a shrine of pictures and flowers by the steps. The community payback group are near the top of the steps. Convict 55 calls out to her.)
STAN: Cheer up, love. Might never happen.
GEORGE: (No. 22, an Indian man) Have some respect. She's grieving.
STAN: Oh, sorry, love. I didn't mean nothing by it.
(Clara walks on, and Rigsy runs after her. The underpass proper is decorated with Banksy-style images of people with their backs to us, men and women including one with a child.)
RIGSY: Sorry about them. They're idiots.
CLARA: That's all right, don't worry. I've heard worse.
RIGSY: I've lost someone, too. My Aunt Karina. Deaf as a post. Didn't really know her that well but she's still gone. Is your one in the mural?
(He strokes the back of a small woman in a yellow jacket.)
CLARA: Oh, no. I haven't actually
RIGSY: I'm sure they'll get round to it at some point. I'm not really with that lot out there. I just have to do this community service thing. I just do graffiti. Not anything, you know, murdery or
CLARA: So, er, what's all this about? What's happened to all these people?
RIGSY: You mean you don't know?

[Tardis]

CLARA [OC]: Hey, I think I've found something. People are missing all over the estate.

[Waste ground]

(Clara is reporting in via mobile phone.)
CLARA: Do you think there's a connection?
DOCTOR [OC]: Could be.
CLARA: And where are you?
DOCTOR: [OC]: Exactly where I was.
CLARA: No, you're not. I'm here and I can't see. Oh.
DOCTOR [OC]: Yes. Oh.
(The Tardis is maybe six inches high. Clara laughs.)
CLARA: Oh, my God, that is so adorable. Are you in there?
DOCTOR [OC]: Yes, I am.

[Tardis]

DOCTOR: And, no, it's not adorable. It's very, very serious.
(The Doctor takes a small item from a wooden box.)
CLARA [OC]: So is this more shrink ray stuff? Are you tiny in there?
DOCTOR: No. I'm exactly the same size. It's merely the exterior dimensions that have changed.
(The door is a tiny thing in the middle of a wall. He opens it.)

[Waste ground]

(We can see most of the Doctor's face through the open double doors.)
DOCTOR: Stop laughing. This is serious.
CLARA: Yeah, well, I can't help it, can I, with you and your big old face. How are you going to get out?
DOCTOR: Well, plainly I can't. Something nearby is leeching all the external dimensions.
CLARA: Aliens?
DOCTOR: Possibly. Oh, who am I kidding? Probably. Sensors are down and I can't risk taking off with it in this state. Clara, I need you to pick up the Tardis. Carefully. It should be possible. I've adjusted the relative gravity.
(She does.)

[Tardis]

CLARA [OC]: You mean you've made it lighter.
DOCTOR: Clara, it's always lighter. If the Tardis were to land with its true weight, it would fracture the surface of the Earth.
CLARA [OC]: Yeah, maybe a story for another time. What now?
DOCTOR: I've managed to get a rough fix on the source of the dimensional leeching.

[Waste ground]

(The Doctor's fingers poke out of the door.)
DOCTOR: It's roughly north west. That way.
CLARA: Please don't do that. That's just wrong.

[Tardis]

(He runs back to the console to get some objects.)
DOCTOR: Now, listen! You're going to need these.

[Waste ground]

(He hands out the psychic paper.)
CLARA: Oh, wow. This is an honour. Does this mean I'm you now?
DOCTOR: No, it does not, so don't get any ideas.
(And the sonic screwdriver. She puts the Tardis in her shoulder bag.)
DOCTOR: And listen, stick this in your ear.

[Tardis]

DOCTOR: Can you hear me?
CLARA [OC]: Yes.

[Waste ground]

CLARA: Ow! What just happened?
DOCTOR [OC]: Nanotech.

[Tardis]

DOCTOR: I just hacked your optic nerve.
CLARA [OC]: What does that mean?
DOCTOR: I see what you see.

[Shopping precinct]

(Clara turns around, pointing the screwdriver at a block of flats then a wall with a mural of footprints, hand prints and tyre marks.)
CLARA: Anything?

[Tardis]

(The view is on the scanner.)
DOCTOR: Yes, I'm dizzy. But nothing useful.
RIGSY [on scanner]: You never did tell me your name.
DOCTOR: No time to fraternize. Come on, get rid of him.
CLARA [OC]: I'm er

[Shopping precinct]

(The community service workers are on a meal break.)
CLARA: I'm the Doctor.

[Tardis]

DOCTOR: Don't you dare.
CLARA [OC]: Doctor Oswald.

[Shopping precinct]

CLARA: But you can call me Clara.
RIGSY: I'm Rigsy. So er, what are you a doctor of?

[Tardis]

DOCTOR: Of lies.
CLARA [OC]: Well, I'm usually quite vague about that.

[Shopping precinct]

CLARA: I think I just picked the title because it makes me sound important.

[Tardis]

DOCTOR: Why, Doctor Oswald, you are hilarious.

[Shopping precinct]

DOCTOR: [OC]: Could we get back to work, do you think?
RIGSY: What are you exactly? You don't smell like police but that's some pretty cool gear you got there.

[Tardis]

RIGSY [on scanner]: You like a spy, or something?
DOCTOR: Oh, he's a bright one, hang on to him.

[Flat]

RIGSY: He was the last one to go missing.
(Rigsy breaks the Police tape across the front door.)
RIGSY: And when he disappeared all the doors and windows were locked from the inside.
DOCTOR [OC]: Ooh, now you're talking. I love a good locked room mystery.
(On the wall behind behind a bookcase of CDs is an interesting mural of what looks like a cracked sandy surface.)
CLARA: Yeah, doesn't everyone?
RIGSY: What?
CLARA: Huh? Oh, sorry. I'm talking to somebody else. He's listening in. Doctor, Rigsy, Rigsy, the Doctor.

[Tardis]

DOCTOR: Hello, barely sentient local.
RIGSY [on scanner]: Another Doctor?
DOCTOR: How do you sleep at night?

[Flat]

DOCTOR [OC]: Missing people, tiny Tardis, what's the link?
(Clara scans with the screwdriver.)
RIGSY: I think this is great that someone's finally looking into this. The police weren't doing anything. They never do on this estate. People were thinking that no one was listening. That no one cared.

[Tardis]

RIGSY [OC]: So, yeah. I think it's great what you're doing.
DOCTOR: Clara, look, I think that we can manage on our own from now on.

[Flat]

CLARA: Yeah, well, I think he could still be useful.
DOCTOR [OC]: He's a pudding brain.

[Tardis]

DOCTOR: Worse than that, he's a fluorescent pudding brain.
CLARA [OC]: Okay, fine.

[Flat]

CLARA: And all those other missing people, I suppose you know where they lived.
RIGSY: He could still be in the room.
CLARA: Sorry, what?
RIGSY: Sorry, nothing. I was just thinking out loud.

[Tardis]

RIGSY [OC]: It's like one of those locked room things you get in books.

[Flat]

(Clara looks at herself in the oval mirror over the mantlepiece.)
RIGSY: It's always something weird, like, he's still in the room or something.

[Tardis]

RIGSY [OC]: Do you want to go and check out another flat?
DOCTOR: Do you know, I think that you were wrong about this lad. I think that he could be very useful. Vital local knowledge.
CLARA [on scanner]: Oh, really?
DOCTOR: Yes. So try not to scare him off.
CLARA [on scanner]: How would I scare him off?

[Flat]

(Clara carries on scanning. Rigsy looks at that mural.)
RIGSY: Maybe he's lost in the desert, or something.
CLARA: Okay, right

[Tardis]

CLARA [OC]: Are we missing something here? Missing man, locked room.
(The scanner image zooms in on the mural.)
CLARA [OC]: Shrink ray?

[Flat]

RIGSY: Sorry, did you say just say shrink ray?
CLARA: What if he is still in this room like you said, only tiny? You know, like underneath the sofa or something.
DOCTOR [OC]: Clara, this is the

[Tardis]

DOCTOR: Scaring off that we were talking about.

[Flat]

RIGSY: Okay. So er, my lunch break's nearly up. This this has been er, interesting.
DOCTOR [OC]: Clara, local knowledge is leaving. Do something!
CLARA: Rigsy! One sec. Doctor, open the doors.

[Tardis]

DOCTOR: I didn't mean that!

[Flat]

CLARA: Look, you want him to stay or not?

[Tardis]

DOCTOR: You really do throw your companions in at the deep end, don't you?

[Flat]

(Clara puts the Tardis on a shelf.)
CLARA: Rigsy, come here. Meet the Doctor.
(The Doctor is visible through the Tardis doorway, but standing back from it, so not as way out of proportion as earlier.)
CLARA: So, what do you think? Tiny man idea.
DOCTOR: Yes, it's a lovely thought. Which is why I set the sonic to scan for that as soon as we entered. Pleased to meet you.
CLARA: And you didn't think to tell me?
DOCTOR: Well, of course he might have been squashed under a policeman's shoe by now.
RIGSY: It's bigger. On the inside.
DOCTOR: Do you know, I don't think that statement's ever been truer.
RIGSY: What are you? Like, aliens, or something?
CLARA: No. Well, he is.
(Sizzle! An alarm sounds in the Tardis.)
CLARA: Doctor? Doctor, did you hear that?

[Tardis]

DOCTOR: Yes. Whatever it was, it just drained a massive amount of energy

[Flat]

DOCTOR: From inside the Tardis.

[Tardis]

CLARA [OC]: What was it?

[Flat]

DOCTOR: I don't know, but that's the least of my problems. Just get us out of there.
(He slams the door shut.)
CLARA: Okay. Go. Rigsy, this is where we run. Stick with me.

[Tardis]

DOCTOR: I mean this is just embarrassing. I'm from the race that built the Tardis. Dimensions are kind of our thing. So why can't I understand this?

[Street]

DOCTOR [OC]: Clara, I need more info. Where else have people disappeared?

[Mr Heath's home]

(A policewoman is looking at the psychic paper.)
FORREST: MI5?
CLARA: Yes, this case has got our attention.
FORREST: Well, you've come to the right place, ma'am. First reported disappearance, a Mister Heath. It's not on the estate, but it's exactly the same MO as the rest
DOCTOR [OC]: Clara, I think that your shrink

[Tardis]

DOCTOR: Ray theory was wrong.

[Mr Heath's home]

CLARA: My shrink ray theory? I thought you were already scanning for that.
FORREST: It's like they vanished.
CLARA: Doctor? What are you doing?

[Tardis]

DOCTOR: It just struck me. Locked room mysteries. Classic solution number one, they're still in the room. Classic solution number two, they're in the walls.

[Mr Heath's home]

CLARA: What do you mean, they're in the
(Clara pulls a lump hammer from her bag, supplied by the Doctor from his workbench.)
FORREST: Have we done as much as we could? No. Do we have any suspects? No. Off the record, I think the top brass are hoping if they ignore this it'll all just go away.
CLARA: Apparently they're in the walls.
(Rigsy slams the hammer into the plaster work then hands it to Clara. PC Forrest's phone rings.)
FORREST: PC Forrest. Yes, sir. MI5, sir.
(She goes out to continue the conversation.)
RIGSY: So, you and that bloke in a box. You do this sort of stuff a lot?
CLARA: Oh, well, he's usually out of the box. But, yep.

[Mr Heath's front room]

FORREST: I don't know. Maybe they thought we weren't doing enough, sir.
(The wall wibbles behind her. She turns.)
FORREST: Can I call you back?
(She shines her torch on the 60s decor.)

[Mr Heath's home]

RIGSY: So how'd you get this gig? You study science, or aliens, or something?
CLARA: (laughs) No. Well, it's kind of a more of a right place, right time or wrong place, wrong time depending on how he's behaving.
DOCTOR [OC]: I can hear you, you know.

[Mr Heath's front room]

(The carpet wibbles towards Forrest's feet.)
FORREST: Ma'am, there's something in here, I think.
(She screams as her leg is pulled into the carpet. Rigsy and Clara get there just after she disappears.)
CLARA: PC Forrest? Hello? Hello?
(The torch is lying on the carpet and there is a new mural on the wall behind the sofa. A design of almost completely bilaterally symmetrical red lines.)
CLARA: Doctor, she's gone.

[Tardis]

DOCTOR: What am I missing? The Tardis should be able to detect anything in the known universe. The known universe. This universe.
(The scanner shows what Clara can see looking around the room.)
DOCTOR: Clara, wait, go back.

[Mr Heath's front room]

DOCTOR [OC]: Back, back, back. That mural.

[Tardis]

DOCTOR: That is a nervous system

[Mr Heath's front room]

DOCTOR [OC]: Scaled up and flattened. I think we've found PC Forrest. What's left of her, at least.
CLARA: Her nervous system.

[Tardis]

(The Doctor calls up previous images on the scanner.)
DOCTOR: The mural in the flat. That wasn't a desert at all. It's a microscopic blow up of human skin.

[Mr Heath's front room]

CLARA: What? Why?
DOCTOR [OC]: Whatever they are, they are experimenting. They're testing. They are, they are dissecting. Trying to understand us.

[Tardis]

DOCTOR: Trying to understand three dimensions.

[Mr Heath's front room]

(There is the sizzling or hissing sound, then the door slams shut.)
RIGSY: Ow. The handle.
CLARA: Doctor. The handle, they've flattened the handle.

[Tardis]

DOCTOR: Fascinating. Clara, they're in the walls!

[Mr Heath's front room]

DOCTOR [OC]: Keep away from them. If they touch you, you're finished.
(The sofa and cushions lose their third dimension.)
RIGSY: What happens if they touch us?
(Then an comfy chair goes.)
CLARA: I really don't want to find out.
(They climb onto a handy hanging seat.)
RIGSY: They can't jump, can they?
(Clara's mobile phone rings.)
CLARA: Hey, you.

[Park]

DANNY: I've got our bench. Did you get held up?

[Mr Heath's front room]

CLARA: Just a little. Sorry, Danny. I think lunch is er, a bust.
(The enemy is making the carpet wibble as it moves towards them.)
DANNY [OC]: Oh, hon, you're missing

[Park]

DANNY: Some classic park action.

[Tardis]

DOCTOR: Clara, the window!

[Mr Heath's front room]

(The fireplace then mantlepiece wibble. In fact, the wibble is coming at them from all directions, except down.)
RIGSY: Look! Look! They're climbing the walls.
DANNY [OC]: Who was that?
CLARA: Er, that's just a guy on community support and I'm helping him find his auntie.

[Tardis]

DOCTOR: Nice. Not technically lying.

[Park]

DANNY: Sounds kind of active.

[Mr Heath's front room]

(Clara is swinging the seat on its chain towards the bay window, as the wibble heads across the ceiling.)
CLARA: Er, yeah, there was a thing, er a thing.

[Park]

DANNY: Where are you and are you in trouble?

[Mr Heath's front room]

CLARA: No, no, no, I'm fine!
(Clara sonicks the window and the chain comes away from the ceiling. Crash!)

[Park]

DANNY: Clara?
(Sounds of screams.)
DANNY: Clara?

[Mr Heath's front garden]

(A car alarm is sounding. Rigsy and Clara are safe amongst the shattered windows.)
CLARA: Danny?
DANNY [OC]: What's happening?
CLARA: Oh, not much, just some nonsense. Long story.
DANNY [OC]: What story?
CLARA: Tell you later. Love you!

[Tardis]

DOCTOR: This explains everything. They're from a universe with only two dimensions. And, yes, that is a thing. It's long been theorised, of course, but no one could go there and prove its existence without a heck of a diet.
(See Flatland, by Edwin Abbott Abbott, written 1884 and available at Project Gutenberg.)
DOCTOR: And what long story are you going to tell Danny, huh? Or haven't you made it up yet?
CLARA [OC]: Sorry, what? What was that?

[Subway]

DOCTOR [OC]: Excellent lying, Doctor Oswald.
CLARA: Yeah? Well, thought it was pretty weak myself.

[Tardis]

DOCTOR: I meant to me. You told me that Danny was okay with you being back on board the Tardis.

[Subway]

CLARA: Well, he is.

[Tardis]

DOCTOR: Yeah, because he doesn't know anything about it.

[Subway]

CLARA: Doctor
DOCTOR [OC]: Congratulations. Lying is a vital survival skill.
CLARA: Well, there you go.

[Tardis]

DOCTOR: And a terrible habit.

[Subway]

(Clara gets static in her earbud.)
CLARA: Ah. Doctor, you're breaking up a bit.
DOCTOR [OC]: Yeah, of course I am.
CLARA: No, really, you are. I can't hear you.

[Tardis]

DOCTOR: What? Oh, right, blowing out that window's possibly affected the earpiece. Take it out and sonic it.

[Subway]

CLARA: Doing it.
(Rigsy goes around the corner to see his work group painting over the mural.)
RIGSY: Hey! They can't do that. Hey! What you doing?
FENTON: Our job. You're on report, by the way. Late back from lunch.
CLARA: Does it even still count as lying if you're doing for someone's own good? Well, like, technically their own good.
RIGSY: It's a memorial!

[Tardis]

FENTON [on scanner]: Council didn't approve it, it's graffiti. Stan.
(Rigsy grabs the paint brush from Stan.)
DOCTOR: Look, Clara. Talk to me, talk to me!
RIGSY [OC]: What are you doing?

[Subway]

(The Doctor's fingers stick out of Clara's bag and jog her elbow.)
DOCTOR: Clara, the mural. Clara, it's the mural! Over there, look, the mural! We've found the missing people, they're in the walls!
(Clara puts her ear bud back in.)
CLARA: What do I do?

[Tardis]

DOCTOR: Act normal, but get everyone out.

[Subway]

CLARA: They're very realistic. Who painted them?
RIGSY: I don't know. A local artist.

[Tardis]

RIGSY [OC]: Probably a grieving relative.
CLARA [OC]: Did you ever meet them?

[Subway]

CLARA: Or did they just appear after people disappeared?
FENTON: And who are you when you're at home, love?
(Clara brandishes the psychic paper.)
CLARA: Health and safety. This subway is unsafe. Everyone needs to leave right now.
FENTON: This is blank. Try again, sweetheart.
CLARA: What?

[Tardis]

DOCTOR: What? It takes quite a lack of imagination to beat psychic paper.

[Subway]

FENTON: Stan. Do your job.
DOCTOR [OC]: Clara, stop him.
(Stan's brush touches the wall and he is sucked in with a cry.)
RIGSY: Stan!
(The images on the wall turn around to face them.)
AL: What is this? What are they?
DOCTOR [OC]: They're wearing the dead like camouflage.
CLARA: Forget Stan. Your friend's gone.
DOCTOR [OC]: Clara, get them out of there!
CLARA: We need to move. Now.
(They run as the paintings slide off the wall and move across the tarmac.)

[Train shed]

(The team run into the nearby train shed and close the corrugated iron door. Clara uses the sonic screwdriver to scan.)
GEORGE: Did they follow us? Cos I didn't see them follow us. Are we safe?
AL: Are we really hiding from killer graffiti? This is insane.
DOCTOR [OC]: I agree.

[Tardis]

DOCTOR: We'll have to think of a better name for them than that.

[Train shed]

GEORGE: And Stan was one of them. Flattened, dead, but coming after us.
DOCTOR [OC]: Clara, this is a

[Tardis]

DOCTOR: Vital stage. This little group is currently confused and disorientated

[Train shed]

DOCTOR [OC]: But pretty soon a leader is going to emerge. You need to make sure that leader is you.
CLARA: I'm on it. George. George, isn't it? Can you watch that area? If you hear anything, anything moves, you shout, okay?
FENTON: He will do no such thing until I get some answers. Who are you? That's what I want to know. Impersonating a government official. Trespassing on council property.
CLARA: Seriously?
FENTON: Seriously.
CLARA: Fine, I'll tell you who I am. I am the one chance you've got of staying alive. That's who I am.

[Tardis]

DOCTOR: Well done.

[Train shed]

(The work group go to Clara.)
CLARA: Rigsy, how well do you know this area? Do you know where that door leads?
RIGSY: It's the old Brunswick line. But it's not safe.
AL: Well, there's safe and there's safe.
RIGSY: Yeah, I know it. I used to go down there all the time.
FENTON: Yeah, I'll bet you did. Painting your filth.
CLARA: Yeah, well, you might be glad he did. Those things come in here, that is our only way out. (sotto) I just hope I can keep them all alive.

[Tardis]

DOCTOR: Ah, welcome to my world. So what's next, Doctor Clara?

[Train shed]

CLARA: Lie to them.
DOCTOR [OC]: What?
CLARA: Lie to them. Give them hope. Tell them they're all going to be fine. Isn't that what you would do?

[Tardis]

DOCTOR: In a manner of speaking. It's true that people with hope tend to run faster, whereas people who think they're doomed

[Train shed]

CLARA: Dawdle. End up dead.

[Tardis]

DOCTOR: So that's what I sound like.

[Train shed]

FENTON: Who's she talking to?
AL: He says it's MI5.

[Tardis]

DOCTOR: Right, here's something that might help you. Do you remember the graffiti from the estate? Footprints, tyre treads?

[Train shed]

CLARA: Vaguely.
DOCTOR [OC]: Well, I don't think it was graffiti. I think that that is 

[Tardis]

DOCTOR: How those creatures saw us.

[Train shed]

DOCTOR [OC]:The impressions we make in two dimensional space. That was them reaching out, attempting to talk.

[Tardis]

DOCTOR: At which point they moved into flattening and dissection. Trying to understand. Trying to emulate. But here's the big question. Do they know they're hurting us?
CLARA [OC]: So what?

[Train shed]

CLARA: You think this is all one big misunderstanding?
DOCTOR [OC]: That's a very good question. Why don't we ask them?'
(So while George keeps watch, Rigsy gets a step ladder for Clara to go up to sonick the tannoy speakers.)
DOCTOR [OC]: We need to find a way to communicate.
CLARA: Why can't the Tardis just translate?

[Tardis]

DOCTOR: Because their idea of language is just as bizarre as their idea of space. Even the Tardis is confused.
FENTON [OC]: This is a bad idea.

[Train shed]

FENTON: What makes this colleague of yours think those monsters even want to talk?
DOCTOR [OC]: I know a race

[Tardis]

(The Doctor is searching the Tardis for something.)
DOCTOR: Made of sentient gas who throw fireballs as a friendly wave. I know another race with sixty four stomachs who talk to each other by

[Train shed]

DOCTOR [OC]: Disembowelling.
CLARA: He's got a hunch.
DOCTOR [OC]: My point being that in a universe as immense and bizarre as this one, you cannot be too quick to judge.

[Tardis]

DOCTOR: Perhaps these creatures don't even understand that we need three dimensions to live in.
(He reaches underneath the console.)
DOCTOR: They may not even know that they're hurting us.

[Train shed]

CLARA: Do you really believe that?
DOCTOR [OC]: No. I really hope that.

[Tardis]

DOCTOR: It would make a nice change, wouldn't it? Okay. Let's start with pi. Even in a flat world they would have circles. I don't mean edible pie, I mean circular pi. Which I realise would also mean edible pie but anyway.
(He types on the console, then the screwdriver flickers and sounds come out of the speakers.)
DOCTOR: They're responding. The Tardis is translating now.

[Train shed]

DOCTOR [OC]: It's a number. Fifty five.
CLARA: Fifty five? What does that mean?

[Tardis]

DOCTOR: Tenth Fibonacci number. Atomic number of caesium.

[Train shed]

RIGSY: I know what it means. We all have numbers on our jackets. Have to sign them out.

[Tardis]

RIGSY [OC]: That was the number on Stan's jacket, the man they flattened in the subway.

[Train shed]

FENTON: They're gloating.

[Tardis]

DOCTOR: We don't know that.

[Train shed]

CLARA: It could be an apology, for all we know?
AL: Really? That's nice of them.
FENTON: An apology? Are you seriously
(More sounds.)
CLARA: Shush, shush, shush. Listen. Wait.
DOCTOR [OC]: Two two. Twenty two.
CLARA: Twenty two.
RIGSY: That's George.
FENTON: Looks like your number's up, George. Now they're threatening.
CLARA: Maybe. Or maybe they're showing us they can read.
FENTON: Oh, grow up. They're picking targets.
RIGSY: Of course you'd see it that way.
FENTON: What do you mean by that?
CLARA: George?
(George is standing very still.)
RIGSY: Everyone's out to get you, aren't they?
FENTON: In this case, they kind of are.

[Tardis]

DOCTOR: Clara, be careful.

[Train shed]

(Clara steps to one side whilst looking at George, and sees that he is just a two dimensional image. Then that dissolves into the wall and floor.)
CLARA: The tunnel!

[Tardis]

CLARA [OC]: Doctor, they've got George.
DOCTOR: I know. I did see.
CLARA [OC]: What now?
DOCTOR: Give me a minute. I'm working on it.
(The Doctor is at his workbench, building a gizmo.)

[Disused tunnel]

(At a steel door with a wheel in the middle. You know this tunnel is disused because the railway tracks have been removed.)
CLARA: Another flat handle. They were here. Not now. They've stopped chasing us, I think. It feels like they're cornering us.
DOCTOR [OC]: You can't apply human logic. You're dealing with creatures from another dimension.
AL: That's three exits all blocked by those creatures.
CLARA: Rigsy, where's the next exit?
RIGSY: The only other one I can think of is where the old line joins the new, but it's a fair walk. Getting through that door would be quicker.
FENTON: But we can't, can we?
RIGSY: I'm just saying.
DOCTOR [OC]: Clara, I might be able to help with that door.

[Tardis]

DOCTOR: Give me five minutes.
(The hand sized gizmo is taking shape.)

[Disused tunnel]

(Further on, they come across a painting of something exploding out in a circle.)
RIGSY: It's one of mine. Do you like it?
CLARA: Yeah, not bad. So this thing you're working on?
DOCTOR [OC]: I think I've figured out a way to restore three dimensions. At least on a small scale, say

[Tardis]

DOCTOR: Door handles.
CLARA [OC]: So, what's that, then?

[Disused tunnel]

CLARA: A de-flattener?
DOCTOR [OC]: We're not calling it a de-flattener.
(The Doctor hands it out of her bag. Basically a very old calculator with a ball on top and an extra aerial.)
DOCTOR [OC]: This should be able to restore dimensions. You see what I've called it?
CLARA: Two D is. Two Dee Iz?

[Tardis]

DOCTOR: No. Twodis. It's called the Twodis. (sigh) Why'd I even bother? Well, give it a go, then.

[Disused tunnel]

(Clara aims it at the flat wheel on the steel door. Green rays pulse out of the ball like smoke rings, then there is real smoke and a small bang.)
CLARA: Long way round it is.

[Tardis]

(An alarm sounds.)
DOCTOR: Clara, I don't know how, but they're doing it again. They're leeching the Tardis!
CLARA [OC]: How? Your doors are closed.
DOCTOR: They've changed frequency. This time it's different.
CLARA [OC]: Listen!

[Disused tunnel]

CLARA: The Doctor thinks we might be in trouble. He thinks they might be close.
FENTON: Where, exactly?
CLARA: I don't know. He's not sure. He's getting readings all around.
(Something forms a shadow in the light coming down the tunnel.)
FENTON: Oh, that's just great. Sounds important but means absolutely nothing. Can you tell your friend
(A giant hand rushes down the tunnel and grabs Al, lifting him up into the air and taking him back from whence it came. Naturally, he screams.)
AL: Aaaargh! Aaaaaaaaargh!

[Tardis]

DOCTOR: Of course. The next stage. 3D.

[Disused tunnel]

(Lumps appear in the tunnel floor, which then try to resolve themselves into PC Forrest and others as they rise up.)
RIGSY: Run!
CLARA: Doctor? The door.

[Tardis]

CLARA [OC]: The handle's flattened.

[Disused tunnel]

(The Twodis is handed out of Clara's bag again.)
DOCTOR: I've boosted the output.
CLARA: And it will work this time?

[Tardis]

DOCTOR: Absolutely.

[Tunnel]

(This time there is a steady stream of green smoke rings, and the wheel becomes three dimensional again. Rigsy opens it, they go through and lock it.)
DOCTOR [OC]: Clara, stop. Use it again. It can reverse the process.
RIGSY: There's a ladder at the end of this. If we get down into the tunnel, we can make it into daylight.
CLARA: Hang on! Hang on.
(Clara Twodises the wheel into two dimensions again.)
FENTON: If it's flat, we're safe now, aren't we?
RIGSY: They can't get through, can they?
CLARA: Wait.
(On the other side, the indistinct, wobbly people aim red energy at the flat wheel, and it becomes 3D again. They run.)

[Tardis]

DOCTOR: They have a new ability. Of course they have. Now they're 3D, they can restore dimensions.

[Tunnel]

(As wobbly Stan and PC Forrest lead the rest of the figures through the door, Clara leads the men in a run for their lives. These creatures are difficult to describe. Sort of made up of squares of the surface of people, which aren't stuck together and shift around a little as they move.)
DOCTOR [OC]: Clara, do you want the good news or the bad news?
CLARA: We're in the bad news! 

[Tardis]

CLARA [OC]: I'm living the bad news!
DOCTOR: The good news is I've come up with a theoretical way to send them back to their own dimension.

[Tunnel]

CLARA: Do it! Now!
DOCTOR [OC]: And that's the bad news. The Tardis doesn't have enough dimensional energy to pull it off.
CLARA: Great. What do you want me to do about it?

[Tardis]

DOCTOR: Apparently these things can pump it out as fast as they can steal it.

[Tunnel]

CLARA: Maybe if I ask them really nicely, they'll fill you up again. Hey!
(Fenton reaches into Clara's bag, pulling the Tardis out.)
FENTON: Give me that machine! Hand it over!
(As Rigsy and Fenton struggle for the Twodis, the Tardis goes flying over a railing and down a ventilation shaft.)
CLARA: Doctor?
(It lands with a thump, and alarms sound.)
CLARA: Hello? Doctor? Look, can we please deal with this later? Because we need to move.

[Tardis]

(The Tardis has completely lost power.)
CLARA [OC]: Doctor? Doctor, I dropped you down a hole. Where are you?
DOCTOR: I don't know. My shields have gone. Structural integrity is failing. Another blow like that and I've had it.
(He looks out of the tiny doors.)
DOCTOR: Er, I'm on the train lines. And there's a train coming. Of course there is. Short-term re-materialisation? Not enough power. Teleport? Not enough power. Re-route the heart of the Tardis through - not enough power! Not enough power!
(Train A113 is hurtling along the tracks, sounding its horn. The Tardis has, of course, landed on a crossing point, where the track which is sunk into concrete slabs, so there isn't the usual clearance for the train to just run over something so small.)
CLARA [OC]: Can't you move the Tardis?
DOCTOR: Clara, there is no power. The Tardis couldn't boil an egg at the moment. Listen, do what you can to get those people out of there.

[Tunnel]

DOCTOR [OC]: You're stronger than you know.
RIGSY: I wonder what they're like with ladders?
CLARA: No, I mean you move the Tardis. Like

[Tardis]

CLARA [OC]: Addams Family.
(As the train bears down on him, the Doctor sticks his hand through the doors and turns the Tardis upright, then uses his fingers to walk along the concrete, over the recessed track and then slightly up a slope. He pulls his hand in and closes the door in order to celebrate with the Addams family theme tune.)
DOCTOR: Ha! Di di di.
(The vibration caused by the train coming down the tunnel knocks the Tardis over so that it is leaning towards the rail as the train bears down. The Doctor looks out, then dives underneath the console, reaches up and pulls something.)

[Tunnel]

(Clara gets static in her earbud.)
CLARA: Doctor? Doctor? 

[Track]

(Rigsy and Fenton have climbed down the ladder to the track.)
RIGSY: They'd be here if they were coming. Where are they?
FENTON: There's no other way down, right? Hey! I'm talking to you.
RIGSY: There is. An old service elevator near the mouth of the tunnel.
(Clara comes down the ladder.)
CLARA: We should go.
FENTON: Oh, no.
(Jerky shadows play against the light at the end of the tunnel.)
FENTON: And there's another train coming.
(The horn sounds behind them. This time it is 2M65, Not In Service, barrelling along towards them. Clara quickly sonicks the signals from green to red, and the driver puts on the brakes.)

[Tardis]

(The Doctor has his coat collar turned up, and is rubbing his hands to try and stay warm.)
DOCTOR: I don't know if you can still hear me out there, but the Tardis is now in siege mode. No way in, no way out. I managed to turn it on just before the train hit. But there's not enough power left now to turn it off.

[Track] (The driver climbs down from his cab.)
BILL: What's going on? Why the red light?
CLARA: MI5. We've got a, er
FENTON: Blockage. In the tunnel.
(Rigsy runs back along the train.)
CLARA: Can we ram the blockage? The train's empty, isn't it?
BILL: Yeah, it's out of service, but you'd need someone to hold the dead man's handle. Won't run without it. Is this official? Because I've always wanted to ram something.
CLARA: Can we rig it to drive without that? Send it in with no driver?
(The train starts to move forward. Clara runs to board it.)
CLARA: Rigsy!

[Driver's cab]

CLARA: Er, what are you doing?
RIGSY: I'm going to ram them, buy you some time.
CLARA: You'll die.
RIGSY: Yeah, course I'll die. Now go!
CLARA: Well, why'd you want to do that?
RIGSY: Just go, okay? Let me do this.
CLARA: Okay, fine, yeah. And I'll always remember you.
RIGSY: Fine. Great
CLARA: Cos I was just going to do this.
(She takes a piece of stretchy cord and loops it around the handle and something lower down.)
CLARA: No driver required. And I really like that hair band, but I suppose I'll just take it, will I? And every time I look at it, I'll remember the hero who died to save it. Come on. You're not getting off that lightly. There's work that needs doing.
(Anquished Rigsy makes up his mind and they run back down the train, jumping off just before it becomes a mural on the side of the tunnel.)

[Track]

CLARA: I quite liked that hair band.
(Figures start rising out of the tunnel floor again. As they start to run back, Clara spots a small box with circular Gallifreyan symbols on each side lying by the rails. She picks it up.)
RIGSY: What is it?
CLARA: I think it's the Tardis.
(They run.)

[Office]

(Clara is staring at the cube and tapping her earbud, whilst the train driver is brought up to speed with the plot. This office hasn't been used in a long time. There is a typewriter on a desk, old filing cabinets and a long table.)
BILL: They wear your skin?
FENTON: I never thought I'd say this
BILL: This is insane.
FENTON: But I think preferred them when they were flat.
BILL: What do you mean flat?
CLARA: Doctor?
(Nothing.)
CLARA: Doctor? What would you do now? No. What will I do now? Okay, okay, okay. Okay, the last thing the Doctor said was that the Tardis needed energy. He said if it gets energy, he can beat them.

[Tardis]

(The scanner is still sort of working.)
DOCTOR: No, no, no. What are you doing?

[Office]

(Clara is having an idea. She unrolls an old advertising poster for Bristol LMR out on the table and turns it over, blank side up. She uses the Tardis as a paperweight and shakes a handy paint spray can.)
FENTON: Leave her. She's lost it.
RIGSY: Are you okay?
CLARA: Yeah, are you?
RIGSY: I think I will be. What's this?
CLARA: Come on, Graffiti Boy, I've got a commission for you.
(She throws him the spray can.)
RIGSY: I'm flattered but I don't think this is exactly the time
CLARA: Well, fine, if you don't think you're up to it.
RIGSY: What do you need, exactly?

[Service tunnel]

(The Tardis is placed on a metal ledge, and the trio wait the other side of a two dimensional locked door.)
FENTON: You're going to get us killed. This plan's insane.
CLARA: You want to walk? Walk. You want to stay? Then shush!
BILL: They're coming!
(The strange facsimiles of people stagger along the track to the door.)

[Tardis]

(Time is running out for the Doctor.)
DOCTOR: Life support failing. I don't know if you'll ever hear this, Clara. I don't even know if you're still alive out there.
(The wobbly people aim their red energy at the flat wheel on the steel door.)
DOCTOR: But you were good! And you made a mighty fine Doctor.

[Service tunnel]

(More and more energy is poured in, and still the wheel stays flat. On the other side of the wall -)
FENTON: It's not working. You've killed us all.
BILL: This is going to save us? Pumping energy into the wall?
CLARA: No. Not into the wall. Through the wall. Rule number one of being the Doctor. Use your enemy's power against them.
(The door is directly on the other side of the wall from where the Tardis was placed, and the red energy is streaming into it.)
CLARA: They can't restore three dimensions to a door that never existed.
(The poster starts to peel off the wall. The Tardis shakes and power is restored inside. The Doctor runs to the console and starts using controls. Finally, the cube flies off the ledge, changes shape and flies through the air with its familiar sound, growing bigger and bigger until it lands full sized with a thump by the 3D facsimile people. It puts out a forcefield that pushes them away down the tunnel.)
CLARA: It worked. They charged the Tardis.

[Tardis]

DOCTOR: I tried to talk. I want you to remember that. I tried to reach out, I tried to understand you, but I think that you understand us perfectly.

[Train shed]

(The Doctor's words come over the tannoy system.)
DOCTOR [OC]: And I think you just don't care. And I don't know whether you are here to invade, infiltrate or just replace us.

[Tardis]

DOCTOR: I don't suppose it really matters now. You are monsters. That is the role you seem determined to play. So it seems I must play mine.

[Track]

(The Doctor steps out of the Tardis. Clara, Rigsy and Fenton come down the ladder.)
DOCTOR: The man that stops the monsters. I'm sending you back to your own dimension. Who knows? Some of you may even survive the trip. And, if you do, remember this. You are not welcome here. This plane is protected. I am the Doctor.
(He turns, and Clara throws him the sonic screwdriver.)
DOCTOR: And I name you The Boneless.
(He zaps the forcefield, and pulses of energy make the Boneless disintegrate with a squeal.)

[Waste ground]

(The Tardis materialises. The Doctor, Clara, train driver Bill and Fenton get out, followed by Rigsy who closes the door. Bill gets down on his knees and kisses the ground. Clara chuckles. Rigsy makes a phone call on Clara's phone.)
RIGSY: Hi, Mum. It's me.
CLARA: You all right?
BILL: I'm alive, and I've been inside that. I think I'm up on the deal. Come here.
(Bill and Clara hug. Rigsy is walking away whilst speaking to his mum and Fenton is retying his boot laces.)
BILL: Thank you. (to Fenton) You look chipper.
(Bill walks away.)
CLARA: Do people still say chipper?
DOCTOR: Apparently. Are you okay?
CLARA: I'm alive.
DOCTOR: And a lot of people died.
FENTON: It's like a forest fire, though, isn't it? The objective is to save the great trees, not the brushwood. Am I right?
DOCTOR: It wasn't a fire, those weren't trees, those were people.
FENTON: They were Community Payback scumbags, I wouldn't lose any sleep.
DOCTOR: I bet you wouldn't.
FENTON: It's good to be alive though. Thank you. Seriously, thank you.
(And he walks off, too.)
DOCTOR: Yes, a lot of people died and maybe the wrong people survived.
CLARA: Yeah, but we saved the world, right?
DOCTOR: We did. You did.
CLARA: Okay, so, on balance
DOCTOR: Balance?
CLARA: Yeah, that's how you think, isn't it?
DOCTOR: Largely so other people don't have to.
CLARA: Yeah, well, I was you today. I was the Doctor. And, apparently, I was quite good at it.
DOCTOR: You heard that, did you?
CLARA: Yeah, but the power was going off so I suppose you were delirious. You didn't know what you were saying.
DOCTOR: Yes.
(Rigsy has finished his call with a 'love you' and returns to the Doctor and Clara.)
DOCTOR: Ah! The return of the fluorescent pudding brain.
CLARA: You do realise he can hear you now?
DOCTOR: I know. Your last painting was so good it saved the world. I can't wait to see what you do next.
RIGSY: (chuckles) It's not going to be easy. I've got a hair band to live up to. Thanks.
(He holds out his hand to Clara, and she pulls him in for a hug.)
CLARA: Come here.
(Rigsy leaves.)
CLARA: Admit it. I did well.
(Her phone rings. It is Danny. She picks the I'm in a meeting text option to end it.)
DOCTOR: Is that PE?
CLARA: Just say it. Why can't you just say it? Why can't you just say I did good?
DOCTOR: Talk to soldier boy.
CLARA: It's not him. Come on, why can't you say it? I was the Doctor and I was good.
DOCTOR: You were an exceptional Doctor, Clara.
CLARA: Thank you.
DOCTOR: Goodness had nothing to do with it.
(Mae West, 'Night After Night' 1932.)

[Room]

(Our mysterious Edwardian lady is apparently monitoring all this on her tablet computer. She is looking at a live feed of Clara's face on it.)
MISSY: Clara. My Clara. I have chosen well.
(She laughs.)