Capt. Kirk: In the late nineteenth century in Arizona, two factions fought for control of the town Tombstone. The Earps - Morgan, Virgil and Wyatt - who were the town marshals, along with Doc Holliday.
Spock: And the Clanton gang. On October 26th, they... had it out.
Chekov: Who won?
Capt. Kirk: The Clantons lost, Mr. Chekov.
Chekov: And we... are... the Clantons?
Capt. Kirk: [as Sylvia kisses Chekov passionately] Um, Mr. Chekov?
Chekov: [slowly disengaging] What can I do, Keptin? You know we're always supposed to maintain good relations with the natives.
Melkotian Buoy: [voice] Aliens. You have encroached on the space of the Melkot. You will turn back immediately. This is the only warning you will receive.
Spock: Vulcan, Captain.
Capt. Kirk: English.
Chekov: It was Russian, sir. Every word.
Uhura: No, Captain, it was Swahili.
Capt. Kirk: Interesting. Telepathy.
Spock: Unquestionably. Most impressive.
[Scott has volunteered to test the self-made tranquilizer]
Scott: [pours himself a drink] It's to kill the pain.
[empties the glass in one gulp]
Spock: But this is painless.
Scott: Well, you shoulda warned me sooner, Mr. Spock. Fire away.
Ed: You boys want your usual?
Scott: Absolutely! Er... half a gallon of scotch.
Ed: You know we ain't got nothin' but bourbon, 'less you want corn whiskey.
Capt. Kirk: Who do you think I am?
Ed: Ike Clanton. Who do YOU think you are?
Capt. Kirk: Well, I know this is hard to understand, but I'm Captain James T. Kirk of the spaceship Enterprise. These men are part of my crew. We're not really here. We're from the future.
[Ed starts to laugh]
Capt. Kirk: We haven't been born yet!
[Ed laughs heartily]
Capt. Kirk: Feel the material in my shirt. And now feel the material in your own shirt. Do you notice any difference?
Capt. Kirk: [getting exasperated] Do these clothes look like yours?
Ed: Mmm, not exactly.
Capt. Kirk: Have you ever seen clothes like this before?
Capt. Kirk: Where?
Ed: On the Clantons.
Ed: You Clantons are always great with your jokes. That's why we like you.
Capt. Kirk: I'm not joking.
Ed: Only difference between you and the Earps is that they never joke.
Capt. Kirk: I'm not joking! I'm not Ike Clanton!
Ed: [laughs] It's okay with me, Ike. Anything you say. Don't make no difference who I think you are. Your problem is: who does Wyatt Earp think you are?
McCoy: Mr. Spock, why don't you join us common humanoids in trying to find a way out of here and quit explaining why we can't get out of here.
[Morgan Earp has shot a man]
Spock: Is this a dead man, Doctor?
McCoy: Very dead, Mr. Spock.
Capt. Kirk: That's one thing we can be sure of here. Death is real.
[Kirk comes precariously close to a shoot-out with Morgan Earp]
Spock: Captain, since we have seen that death is the one reality in this situation, I seriously suggest you reseat yourself immediately, without moving a muscle of either hand. If I remember correctly, that would involve you in what was called 'the fast draw'. It initiated unfortunate events.
Capt. Kirk: [as McCoy wipes Kirk's split lip with bourbon] Ouch!
McCoy: What's the matter?
Capt. Kirk: What do you call that stuff? Fire?
McCoy: [reading the label] Taos Lightning, straight bourbon. Try some. In small amounts, it was considered medicinal.
Capt. Kirk: Well, label it "For external use only".
Spock: I prefer being a welcome guest, Captain, but there seems to be little choice.
Melkotian: [voice] You, Captain Kirk, the disobedience was on your orders. Yours is the responsibility. Yours shall be the pattern of your death.
Capt. Kirk: We come in peace. But we'll defend ourselves if necessary.
Melkotian: [voice] You are outside. You are disease. The disease must be destroyed. Your plea has been heard, and sentence has been pronounced. It is done.
McCoy: [appraising his gun] In the midst of what seems so unreal, the harsh reality. This is not a dream.
Capt. Kirk: I can't just kill 'em! I can't murder them! I can't kill them!
Johnny Behan: Kill 'em any way ye can! There'll be no questions asked. Honest! I-I guarantee that.
Spock: [finishing in the construction of a gas grenade] These crude supplies we were forced to use worked quite well.
McCoy: I doubt that this combination of things was ever used for any purpose quite like this.
Spock: Perhaps they would've been if they'd had your ingenuity, Doctor.
Scott: If we only had a phaser.
McCoy: Or a communicator. It'd be a pleasure to watch those Earps as we beamed back to the ship at exactly 4:59:30.
[Chekov has been shot dead]
Spock: Gentlemen, there is one thing which requires the immediate attention of all of us. Specifically, our future.
Capt. Kirk: But not this minute, Spock. It takes us... a little longer.
Spock: I understand the feeling, Captain.
McCoy: You talk about another man's feelings. What do you feel, Spock?
Spock: My feelings are not subject for discussion, Doctor.
McCoy: Because there are no feelings to discuss!
[Kirk and his landing party find themselves in a strange environment]
Spock: Obviously, this represents the Melkotian's concept of an American frontier town, circa... 1880.
McCoy: It's just bits and pieces. It's incomplete.
Spock: Perhaps the Melkotians have insufficient data about this era.
Capt. Kirk: Or perhaps this is all they require to complete the pattern of our death.
Spock: The violence of your own heritage is to be the pattern for our execution.
Capt. Kirk: Ten minutes. And it's all gonna end at the OK Corral.
Spock: It did not function. But it must function.
McCoy: Nothing could go wrong, Captain. It should work.
Spock: A scientific fact. But if the tranquillizer does not function, which is clearly impossible, then a radical alteration of our thought patterns must be in order.
Spock: Doctor, in your opinion, what killed Mr. Chekov?
McCoy: A piece of lead in his body.
Spock: Wrong. His mind killed him.
McCoy: Well, come on, Spock. If you've got the answer, tell us.
Spock: Physical reality is consistent with universal laws. Where the laws do not operate, there is no reality. All of this is unreal.
McCoy: What do you mean, unreal? I examined Chekov. He's dead.
Spock: But you made your examination under conditions which we cannot trust. We judge reality by the response of our senses. Once we are convinced of the reality of a given situation, we abide by its rules. We judge the bullets to be solid, the guns to be real. Therefore they can kill.
Spock: [mind-melding with McCoy] The bullets are unreal. Without body. They are illusions only. Shadows without substance. They will not pass through your body, for they do not exist.
McCoy: [in a trance] They do not exist.
Spock: [mind-melding with Kirk] Unreal. Appearances only. They are shadows. Illusions. Nothing but ghosts of reality. They are lies. Falsehoods. Specters without body. They are to be ignored.
Spock: This afternoon, you wanted... to kill. Didn't you?
McCoy: But he didn't kill, Mr. Spock.
Spock: But he wanted to, Doctor.
Capt. Kirk: Is that the way it seemed to you, Mr. Spock?
Spock: Yes, Captain.
Capt. Kirk: Mr. Spock - you're absolutely right. That's exactly the way it was.
Spock: Mankind - ready to kill.
Capt. Kirk: That's the way it was in 1881.
Spock: I wonder how Humanity managed to survive.
Capt. Kirk: We overcame our instinct for violence.