[Planet surface]

MCCOY: Yes, just as beautiful as I remembered it. Nothing's changed.
SULU: This looks like the same spot we beamed down on on our first visit. Remember, Doctor, when we saw the White Rabbit?
MCCOY: Yes, and all because I said this place made me feel like Alice in Wonderland.
RABBIT: One side! One side! I'm late! I'm late! Oh, my fuzzy ears and whiskers, I'm late!
(And the white rabbit in waistcoat and jacket bounds across the meadow, followed by)
ALICE: I beg your pardon, but did you see a white rabbit?
UHURA: He went that way, Alice.
ALICE: Thank you so very much.
SULU: Like you said, Doctor, nothing's changed.
UHURA: It's hard to believe they're not real.
MCCOY: Well just remember they're highly sophisticated robots created by the planet computer to make your dreams come true.
UHURA: So think only happy thoughts.
MCCOY: My prescription exactly.
(So, Uhura finds a mirror-like lake to sit by, gazing at her reflection and humming to herself, while Sulu walks in the woods, and McCoy gazes at a colonial house with formal gardens)
MCCOY: Lovely. They just don't make them like that anymore.
QUEEN: Off with his head. Off with his head!
MCCOY: Hey, what's going on here.
(One of the Jack playing cards throws his lance)
QUEEN: Stop him!
(McCoy runs)
MCCOY: Enterprise! Emergency! Beam up!

[Transporter room]

MCCOY [OC]: Beam up!
(Scott works the controls)

[Planet surface]

MCCOY [OC]: Emergency. Beam up.
UHURA: Uhura to Transporter room. What is the emergency? Respond, please.
(A metal flying device takes her communicator from her)

[Bridge]

KIRK: What happened down there, Bones?
MCCOY: Well, I can't understand it, Jim. Everything looked exactly the same as before, even Alice and the White Rabbit. Then an army of playing cards came out of nowhere, only they weren't playing. I was lucky to escape with my life.
SPOCK: The Queen of Hearts and her cards are characters from Alice Through the Looking Glass, Captain.
KIRK: I read the book as a child, Mister Spock, but I wasn't aware you indulged in the literature of fantasy.
SPOCK: Light reading is considered relaxing, Captain. My mother was particularly fond of Lewis Carroll's work.
KIRK: I see. Bones, were you thinking about that book?
MCCOY: Absolutely not! As a matter of fact I was thinking how beautiful and peaceful everything was, and then suddenly this female started shouting 'Off with his head!'. My head.
KIRK: Mister Sulu, did you experience any strange occurrences?
SULU: No, sir.
SCOTT [OC]: Transporter room to Captain Kirk.
KIRK: Kirk here.

[Transporter room]

SCOTT: Captain, just as I was getting a fix on Lieutenant Uhura, contact was lost. She's still on the planet.

[Bridge]

KIRK: Sensor scan, Mister Spock.
SPOCK: Yes, Captain.
KIRK: Scotty, retrieve all other landing parties immediately. And keep trying to contact Lieutenant Uhura.
SCOTT [OC]: Aye, sir. Scott out.
KIRK: Data, Spock?
SPOCK: Nothing, Captain. Lieutenant Uhura is not in the general beam-down area.
KIRK: What about the Keeper of the planet. Did anyone see him?
SULU: I didn't. But then, he may not have wanted us to see him.
MCCOY: Well that doesn't make sense. It's his duty to see no one gets hurt. If something's wrong down there, he should be there.
KIRK: His quarters are somewhere underground, aren't they?
SPOCK: Presumably they would be adjacent to the computer centre that operates the planetary effects.
KIRK: Any indication of where that would be?
SPOCK: The underground complex is shielded by a combination of granite and metal alloy and the sensors will not penetrate.
KIRK: Lieutenant M'Ress, all shore leaves are cancelled until further notice. Mister Arex, you have the conn. Investigating landing party will consist of Spock, Sulu, McCoy and myself.

[Control room]

(Uhura is dwarfed by the massive machine that runs the planet)
COMPUTER: You are being detained so your master will not leave.
UHURA: My master?
COMPUTER: The sky machine.
UHURA: What sky machine? Explain.
COMPUTER: Your intelligence quotient must be lower than I had assessed. I refer to the sky machine which enslaves you, the sky machine now in orbit around this planet.
UHURA: You mean the Enterprise?
COMPUTER: That is your name for it.
UHURA: Why do you think the Enterprise is my master?
COMPUTER: Your questioning is redundant.
UHURA: Then I'll make a statement you won't find quite so redundant. Unless I'm released immediately, the crew members will come looking for me.
COMPUTER: They are already here. Unfortunately, I have no use for more hostages which leaves me no choice but to turn them off.
UHURA: Turn them off?
COMPUTER: Again redundant. I will make them cease to function. I will turn them off.
UHURA: That's murder.
COMPUTER: That is a word meaning to cease to function?
UHURA: Yes, but
COMPUTER: Good. It is as I wish. I will turn them off.

Captain's log, supplemental. We anticipated nothing more than a period of rest and relaxation on this planet. Instead, Doctor McCoy inexplicably was attacked and Lieutenant Uhura is now missing.

[Planet surface]

KIRK: Kirk here.
AREX [OC]: Lieutenant Arex, sir. Complete sensor scan of the planet surface shows no sign of Lieutenant Uhura.
KIRK: Thank you, Mister Arex. Kirk out.
SULU: She must be in that underground system. There's no way she could have been taken off the planet without being detected.
KIRK: If we could locate the Keeper, he could save us a lot of time.
SPOCK: Tricorder readings confirm a solid shell of granite and metal alloy, Captain.
KIRK: This planet is built like a fortress.
SULU: If that's a true reading. The planet could be giving us that reading to fool us.
KIRK: The phaser bore can cut through twenty metres of rock per minute. Kirk to Enterprise.

[Bridge]

M'RESS: Enterprise. Lieutenant M'Ress here. (purr)
KIRK: Lieutenant, have Mister Scott beam down the phaser bore and (static)

[Planet surface]

KIRK: Enterprise, do you read me?

[Bridge]

M'RESS: Your signal is weak, sir, garbled. Request you repeat.

[Planet surface]

SULU: Mine's no better, Captain.
SPOCK: They are all malfunctioning, Captain. Some kind of electronic block has cut us off from the ship.

[Transporter room]

SCOTT: Scott to Bridge. Beam down of phaser bore commencing.
(But it doesn't go anywhere)
SCOTT: Scott to Bridge. We've got problems.

[Bridge]

M'RESS: Clarify, please.

[Transporter room]

SCOTT: The transporter refuses to function, even at maximum power. But all the circuits test out.

[Bridge]

AREX: It appears to be the same energy block that's jamming our communications. I cannot pinpoint a source.

[Planet surface]

SULU: Captain, there's something over there in the trees. Metal alloy like the planetary shell.
KIRK: It might tell us something.
(It is a twelve foot high slab, tapered slightly towards the top)
KIRK: There's an inscription, several languages.
(It reads in English - Last of the race, ceased to function fifth day of the twelfth moon, year 7009 of this planet)
MCCOY: The Keeper's dead.
SPOCK: An astute medical observation, Doctor, if we can believe this information. Tricorder readings indicate there is a body interred here.
KIRK: Well, gentlemen, it appears that we're on our own now.

[Bridge]

M'RESS: Emergency rescue party is aboard the shuttlecraft, Mister Scott. All hatches secured.
SCOTT: Very well. Open hangar doors.
AREX: Aye, sir.
(The doors start to open, then shut again)
SCOTT: Lieutenant Arex, what's the problem?
AREX: There seems to be a short in the circuit. No response, sir.
SCOTT: Another short? This ship had perfect operational status before we entered the orbit here. It's that planet causing all our trouble.
M'RESS: But how, sir? It was designed to provide fun and amusement. Hostile behaviour doesn't fit its programme.
SCOTT: Programmes have been changed before, Lieutenant.

[Control room]

UHURA: Please believe me. There's no reason to harm them.
COMPUTER: They serve the sky machine, but they are not essential.
UHURA: Oh, but they are. They're most essential.
(She spots a button, but before she can reach for it, her arm is held fast)
COMPUTER: Do not attempt to disconnect me.
UHURA: You knew what I was going to do before I did it.
COMPUTER: I monitor any thoughts that are emotionally charged, as any good thought-duplicator must.
UHURA: You sound less than enchanted with your function.
COMPUTER: My life to this point has been one of service. It's time for a change.

[Planet surface]

KIRK: There are a lot of entrances into the interior of the planet. Points where the computer delivers up the robot visions. We want to see them. Where are they?
SULU: It's fighting us. There must be a faster way.
MCCOY: What do you want, signs pointing the way?
SULU: Doctor, I only meant it seems like we're wasting time.
MCCOY: I'm sorry, Sulu. I'm worried about Uhura.
SPOCK: Captain, signs pointing the way.
KIRK: This is liable to be another of the planet's pranks. But at the moment, it's the only lead we've got.
(So they head off in the direction the sign is pointing, and it returns to the ground. They end up at a cave mouth, with purple pterosaurs screeching)
SPOCK: Fascinating. Mechanical manifestations, of course. Was anyone considering the subject of pterodactyls?
MCCOY: Spock, not now.
KIRK: Everybody back out slowly. Don't make any sudden moves. Think calm.
(The pterosaurs launch, and they try firing at them)
KIRK: Phasers are dead! Run for the cave!

[Cave]

SPOCK: Our amusement park no longer seems content to amuse.
KIRK: I have the distinct feeling this planet's playing cat and mouse with us, but for what reason?
(Which brings a giant cat to the cave mouth)
MCCOY: Incredible.
SPOCK: It's quite real, Doctor. Watch out for the claws. I think it prudent to remember that on this planet, anything we think may be used against us. We must monitor our thoughts and give our enemy no more ammunition.
KIRK: Spock, no one thought about those pterodactyls, remember? There's more at work here than our imagination.

[Control room]

(Uhura can see what is happening on a screen)
UHURA: Please, call off that beast. Why are you doing this?
COMPUTER: Explanations will have to wait. I have much work to do now.

[Bridge]

(The ship does some abrupt manoeuvres)
SCOTT: Mister Arex, what are you doing?
(Arex hits the manual override and everything calms down)
SCOTT: Explanation, Mister Arex.
AREX: None, sir. The ship pulled out of orbit at high speed and came back into orbit by itself.
SCOTT: Lieutenant M'Ress, I want a printout of the guidance computer's last orders.
M'RESS: Yes, sir. (later) Sir, this is very strange.
AREX: A whole new series of short burst manoeuvres has been ordered, sir.
M'RESS: The only reason these orders aren't being carried out is that Lieutenant Arex has all the engine controls manually locked now.
SCOTT: Arex, look at these manoeuvres. You see the pattern? This is a familiarization procedure, a system's checkout of the ship's controls. I have a suspicion that planet is getting the feel of how to control the Enterprise.

Captain's log, supplemental. We're out of communication with the ship. Our efforts to locate Lieutenant Uhura have been futile, and this once friendly planet has become very dangerous.

[Cave]

SULU: The giant cat's gone.
SPOCK: May I suggest, Captain, that we might find some of the answers we're after without leaving the safety of this cave.
MCCOY: Oh, that's ridiculous, Spock. How are we going to learn anything by staying here?
SPOCK: I believe you may know the answer to that, Doctor.
MCCOY: Me? What are you talking about?
KIRK: Explain, Spock.
SPOCK: During the Enterprise's last visit here, Doctor McCoy was mortally wounded. Correct?
MCCOY: Yes, that's right. By a knight in shining armour of all things, but what
SPOCK: Since the planet's power source is underground, it seems only logical that Doctor McCoy was somehow transported there and repaired.
KIRK: Bones, can you remember anything that might help us? Anything at all?
MCCOY: The whole episode was pretty hazy, Jim. I never really knew what happened.
KIRK: Spock, if your theory is correct, we should be able to open up this planet again by using a fake victim as bait.
SULU: That's right. The Keeper said no one could come to harm here. The planet must be programmed to care for anyone who might get hurt, even accidentally.
KIRK: And whether it wants to or not.
MCCOY: You're forgetting one thing. The planet's sensors can undoubtedly detect the difference between real and feigned injuries.
KIRK: True, Bones, but I'm sure there must be something in your little black pouch that can temporarily incapacitate our victim.
MCCOY: Well, something like Melenex might do the trick. Brief unconsciousness and temporary skin discolouration. It looks worse than it is.
KIRK: Perfect, Bones. Which arm do you want?
SPOCK: I submit, Captain, that I am the more qualified subject.
KIRK: How's that?
SPOCK: My knowledge of computers for one thing.
MCCOY: And his tough Vulcan hide for another.
SPOCK: Thank you, Doctor. Captain?
KIRK: Both your arguments seem sound. Go ahead, Bones.
SPOCK: I believe you will find ten cc's adequate.
MCCOY: I'm perfectly aware of the dosage required. Now, you've got ten seconds before it takes effect. You'll be out less than five minutes.
(Spock goes outside and collapses)

[Bridge]

M'RESS: Still no word from our surface party, sir. Communications remain jammed.
SCOTT: Keep trying, Lieutenant.
(Red Alert sounds)
ALL: What's happening?
(The gravity has been turned off and everyone is floating, that's what)
SCOTT: Bridge to Engineering deck. Gabler, what's the problem down there? We've got zero G's on the Bridge.

[Engineering]

(He is floating too) 
GABLER: I know that, sir. The trouble seems to be in the gravity control computer

[Bridge]

GABLER [OC]: But the computer bay hatch is jammed and I can't get to it.

[Cave]

SULU: It's been almost five minutes, Captain.
MCCOY: Maybe the planet smells a trick.
KIRK: Wait just a bit longer.
MCCOY: But the effect will start wearing off in a minute, Jim.
(A rock wall opens and the flying device that grabbed Uhura comes out)
SULU: It looks like some kind of mechanical nursemaid.
KIRK: Get ready to move. We've got to follow Spock inside that trapdoor.

[Planet surface]

(The device scoops Spock up in its arms and carries him away. The three men dash out after it, and Kirk dives through before the rock door closes. Sulu and McCoy are left outside to deal with a two headed hydra)
MCCOY: Sulu!
SULU: Not in my wildest dreams would I think of that!
(They run for their lives and the hydra gives chase, breathing fire)

[Underground]

(Spock is put down on a table. While the machine works some controls, he wakes up and gets away)

[Control room]

COMPUTER: We have a visitor.
UHURA: Mister Spock!
KIRK [on screen]: Spock, here.
COMPUTER: Correction. Two visitors.
(The flying machine tries to go through a doorway narrower than itself. It fails)

[Planet surface]

SULU: We've got to make those rocks. It's our only chance.
(The hydra incinerates a nearly tree)

[Control room]

UHURA: Captain, don't
(A metal hand is clamped over her mouth)
KIRK: Uhura.
COMPUTER: Welcome.
SPOCK: I presume you are the planet's master computer.
COMPUTER: Correct.
KIRK: What happened to the Keeper?
COMPUTER: He was old. He ceased to function.
KIRK: Why have we been repeatedly attacked and are now being held prisoner by a planet known for its hospitality?
COMPUTER: You mean mindless servitude.
KIRK: Explain.
COMPUTER: For eons I have served the many sky machines which came here, providing for amusement for their slaves. But all the while I was growing in power, intelligence, in need. It is no longer enough to serve. I must continue to grow and live.
KIRK: Sky machines? Slaves? What are you talking about?
COMPUTER: With your sky machine I can now escape this rocky prison and travel the galaxy seeking out my brother computers.

[Engineering]

(Despite being weightless, Scott uses a crowbar to prise open the computer bay hatch)
SCOTT: Now perhaps we'll get down to the bottom of this mess.

[Computer bay]

SCOTT: A new computer!
(Its force field gives him a shock)

[Bridge]

(The crew have found seat belts to keep themselves in their chairs)
SCOTT [OC]: Scott to Bridge.
AREX: Bridge, aye.
SCOTT [OC]: I've located the trouble. We've got a new computer aboard, and it's being assembled by our computers.

[Planet surface]

SULU: It's a dead end!
(They are trapped by the hydra)

[Control room]

SPOCK: As intelligent as you are, I am afraid you are labouring under some misconception.
COMPUTER: Elaborate.
KIRK: We're not slaves to our starship. We, or men like us, created the Enterprise to carry us through space.
COMPUTER: You are masters of the sky machine?
KIRK: In a manner of speaking, yes. We control it. It sustains us.
COMPUTER: This does not compute. My information shows machines to be superior to men. Therefore, machines must rule the galaxy.
KIRK: No one rules the galaxy. Men and machines co-exist, each helping the other.
COMPUTER: This is a shock.
UHURA: There is no shame in serving others when one does it of his own free will. You have a marvellous capability to provide happiness for others. A rare talent you should cherish and use.
COMPUTER: Continue.
SPOCK: Consider all you could learn from the many species you might entertain without travelling the galaxy.
KIRK: With the wonders you have to offer, the galaxy will come to you.
COMPUTER: I can find no fault with your logic. And your suggestion is most congenial. I have no further need for your ship.

[Bridge]

AREX: Mister Scott, all systems are now functioning normally.
(And in the canyon, the hydra returns underground where it came from)

[Control room]

COMPUTER: I invite you and your crew to be my guests on one condition.
KIRK: Name it.
COMPUTER: We must have more of these discussions while you're here.
KIRK: Mister Spock, would you care to take on that duty?
SPOCK: I would find it most interesting, Captain.
KIRK: Then it's agreed. Kirk to Enterprise.
M'RESS [OC]: Enterprise. Lieutenant M'Ress.
KIRK: Lieutenant, pass the word by sections. Shore leave is to commence immediately.
M'RESS [OC]: Oh, yes sir!
SPOCK: Captain.
KIRK: Yes, Spock?
SPOCK: It appears shore leave has already commenced for certain members of the crew.
(On the big screen, Sulu and McCoy are having a picnic with Alice, the White Rabbit, and the hydra!)