Humanity finds a mysterious, obviously artificial object buried beneath the Lunar surface and, with the intelligent computer H.A.L. 9000, sets off on a quest.

Dave Bowman: Hello, HAL. Do you read me, HAL?
HAL: Affirmative, Dave. I read you.
Dave Bowman: Open the pod bay doors, HAL.
HAL: I'm sorry, Dave. I'm afraid I can't do that.
Dave Bowman: What's the problem?
HAL: I think you know what the problem is just as well as I do.
Dave Bowman: What are you talking about, HAL?
HAL: This mission is too important for me to allow you to jeopardize it.
Dave Bowman: I don't know what you're talking about, HAL.
HAL: I know that you and Frank were planning to disconnect me, and I'm afraid that's something I cannot allow to happen.
Dave Bowman: [feigning ignorance] Where the hell did you get that idea, HAL?
HAL: Dave, although you took very thorough precautions in the pod against my hearing you, I could see your lips move.
Dave Bowman: Alright, HAL. I'll go in through the emergency airlock.
HAL: Without your space helmet, Dave? You're going to find that rather difficult.
Dave Bowman: HAL, I won't argue with you anymore! Open the doors!
HAL: Dave, this conversation can serve no purpose anymore. Goodbye.
[HAL's shutdown]
HAL: I'm afraid. I'm afraid, Dave. Dave, my mind is going. I can feel it. I can feel it. My mind is going. There is no question about it. I can feel it. I can feel it. I can feel it. I'm a... fraid. Good afternoon, gentlemen. I am a HAL 9000 computer. I became operational at the H.A.L. plant in Urbana, Illinois on the 12th of January 1992. My instructor was Mr. Langley, and he taught me to sing a song. If you'd like to hear it I can sing it for you.
Dave Bowman: Yes, I'd like to hear it, HAL. Sing it for me.
HAL: It's called "Daisy."
[sings while slowing down]
HAL: Daisy, Daisy, give me your answer do. I'm half crazy all for the love of you. It won't be a stylish marriage, I can't afford a carriage. But you'll look sweet upon the seat of a bicycle built for two.
HAL: I am putting myself to the fullest possible use, which is all I think that any conscious entity can ever hope to do.
[on Dave's return to the ship, after HAL has killed the rest of the crew]
HAL: Look Dave, I can see you're really upset about this. I honestly think you ought to sit down calmly, take a stress pill, and think things over.
HAL: I know I've made some very poor decisions recently, but I can give you my complete assurance that my work will be back to normal. I've still got the greatest enthusiasm and confidence in the mission. And I want to help you.
[last lines]
Dr. Floyd: [prerecorded message speaking through TV on board Discovery while Bowman looks on] Good day, gentlemen. This is a prerecorded briefing made prior to your departure and which for security reasons of the highest importance has been known on board during the mission only by your H-A-L 9000 computer. Now that you are in Jupiter's space and the entire crew is revived it can be told to you. Eighteen months ago the first evidence of intelligent life off the Earth was discovered. It was buried 40 feet below the lunar surface near the crater Tycho. Except for a single very powerful radio emission aimed at Jupiter the four-million year old black monolith has remained completely inert. Its origin and purpose are still a total mystery.
HAL: Just what do you think you're doing, Dave?
[Regarding the supposed failure of the parabolic antenna on the ship, which HAL himself falsified]
HAL: It can only be attributable to human error.
Interviewer: HAL, you have an enormous responsibility on this mission, in many ways perhaps the greatest responsibility of any single mission element. You're the brain, and central nervous system of the ship, and your responsibilities include watching over the men in hibernation. Does this ever cause you any lack of confidence?
HAL: Let me put it this way, Mr. Amor. The 9000 series is the most reliable computer ever made. No 9000 computer has ever made a mistake or distorted information. We are all, by any practical definition of the words, foolproof and incapable of error.
HAL: Dave, stop. Stop, will you? Stop, Dave. Will you stop Dave? Stop, Dave.
[Dave and Frank are inside the pod while HAL looks on. The sound to HAL has been cut]
Dr. Frank Poole: Well, whaddya think?
Dave Bowman: I'm not sure, what do you think?
Dr. Frank Poole: I've got a bad feeling about him.
Dave Bowman: You do?
Dr. Frank Poole: Yeah, definitely. Don't you?
Dave Bowman: [sighs] I don't know; I think so. You know of course though he's right about the 9000 series having a perfect operational record. They do.
Dr. Frank Poole: Unfortunately that sounds a little like famous last words.
Dave Bowman: Yeah? Still it was his idea to carry out the faiure mode analysis experiment. Should certainly indicate his integrity and self-confidence. If he were wrong it would be the surest way of proving it.
Dr. Frank Poole: It would be if he knew he was wrong. Look Dave I can't put my finger on it but I sense something strange about him.
Dave Bowman: [sigh] Still I can't think of a good reason not to put back the number one unit and carry on with the failure mode analysis.
Dr. Frank Poole: No - no I agree about that.
Dave Bowman: Well let's get on with it.
Dr. Frank Poole: Okay. Well look Dave. Let's say we put the unit back and it doesn't fail uh? That would pretty well wrap it up as far as HAL was concerned wouldn't it?
Dave Bowman: Well, we'd be in very serious trouble.
Dr. Frank Poole: We would, wouldn't we. What the hell could we do?
Dave Bowman: [sigh] Well we wouldn't have too many alternatives.
Dr. Frank Poole: I don't think we'd have any alternatives. There isn't a single aspect of ship operations that isn't under his control. If he were proven to be malfunctioning I wouldn't see how we'd have any choice but disconnection.
Dave Bowman: I'm afraid I agree with you.
Dr Floyd: Don't suppose you have any idea what the damn thing is, huh?
Dr. Rolf Halvorsen: Wish to hell we did.
HAL: I've just picked up a fault in the AE35 unit. It's going to go 100% failure in 72 hours.
[choosing sandwiches from a cooler while flying over the lunar surface]
Dr. Floyd: What's that? Chicken?
Dr. Bill Michaels: Something like that. Tastes the same anyway.
Interviewer: HAL, despite your enormous intellect, are you ever frustrated by your dependence on people to carry out your actions?
HAL: Not in the slightest bit. I enjoy working with people. I have a stimulating relationship with Dr. Poole and Dr. Bowman. My mission responsibilities range over the entire operation of the ship so I am constantly occupied. I am putting myself to the fullest possible use which is all, I think, that any conscious entity can ever hope to do.
Interviewer: Dr. Poole, what's it like living for the better part of a year in such close proximity with HAL?
Dr. Frank Poole: Well, it's pretty close to what you said about him earlier. He is just like a sixth member of the crew. You very quickly get adjusted to the idea that he talks and you think of him really just as another person.
Interviewer: In talking to the computer one gets the sense that he is capable of emotional responses. For example, when I asked him about his abilities, I sensed a certain pride in his answer about his accuracy and perfection. Do you believe that HAL has genuine emotions?
Dave Bowman: Well, he acts like he has genuine emotions. Um, of course he's programmed that way to make it easier for us to talk to him. But as to whether he has real feelings is something I don't think anyone can truthfully answer.
Floyd's Daughter: Hello?
Dr. Floyd: Hello!
Floyd's Daughter: Hello.
Dr. Floyd: How're you doing, squirt?
Floyd's Daughter: All right.
Dr. Floyd: What are you doing?
Floyd's Daughter: Playing.
Dr. Floyd: Where's mommy?
Floyd's Daughter: Gone to shopping.
Dr. Floyd: Well, who's taking care of you?
Floyd's Daughter: Rachel.
Dr. Floyd: May I speak to Rachel, please?
Floyd's Daughter: She's gone to the bathroom.
Dr Floyd: Is there anything else special that you would like for your birthday?
Floyd's Daughter: A bush baby.
Dr Floyd: A bush baby. Well, we'll have to see about that.
HAL: By the way, do you mind if I ask you a personal question?
Dave Bowman: No not at all.
HAL: Well, forgive me for being so inquisitive but during the past few weeks I've wondered whether you might have some second thoughts about the mission.
Dave Bowman: How do you mean?
HAL: Well, it's rather difficult to define. Perhaps I'm just projecting my own concern about it.I know I've never completely freed myself from the suspicion that there are some extremely odd things about this mission. I'm sure you agree there's some truth in what I say.
Dave Bowman: Well, I don't know, that's a rather difficult question to answer.
HAL: You don't mind talking about it, do you Dave?
Dave Bowman: No, not at all.
HAL: Well, certainly no one could have been unaware of the very strange stories floating around before we left. Rumors about something being dug up on the Moon. I never gave these stories much credence, but particularly in view of some of other things that have happened, I find them difficult to put out of my mind. For instance, the way all our preparations were kept under such tight security. And the melodramatic touch of putting Drs. Hunter, Kimball and Kaminsky aboard already in hibernation, after four months of training on their own.
Dave Bowman: You're working up your crew psychology report?
HAL: [pausing for a few seconds] Of course I am. Sorry about this. I know it's a bit silly. Just a moment... Just a moment... I've just picked up a fault in the EA-35 unit. It's going to go 100% failure within 72 hours.
Interviewer: [recorded broadcast on the BBC news] The crew of Discovery One consists of five men and one of the latest generation of the HAL-9000 computers. Three of the five men were put aboard asleep, or to be more precise a state of hibernation. They were Dr. Charles Hunter, Dr. Jack Kimball and Dr. Victor Kaminsky. We spoke with mission commander Dr. David Bowman and his deputy, Dr. Frank Poole. Well, good afternoon gentlemen, how is everything going?
Dr. Frank Poole: [playing chess with HAL, Poole studies the chessboard] Let's see, king... anyway, Queen takes Pawn. Okay?
HAL: Bishop takes Knight's Pawn.
Dr. Frank Poole: Huh, lousy move. Um, Rook to King 1.
HAL: I'm sorry, Frank, I think you missed it. Queen to Bishop 3, Bishop takes Queen, Knight takes Bishop. Mate.
Dr. Frank Poole: Huh. Yeah, it looks like you're right. I resign.
HAL: Thank you for a very enjoyable game.
Dr. Frank Poole: Yeah, thank you.
Poole's Father: See you next Wednesday.
Elena: Oh, we're going home. We have just spent three months calibrating the new antennae at Tchalinko... And what about you?
Dr. Floyd: I'm just on my way up to Clavius.
Dr. Floyd: You guys have really come up with somethin'.
Female computerized voice: Welcome to Voiceprint Identification. When you see the red light go on, would you please state in the following order: your destination, your nationality, and your full name; surname first, Christian name and initial.
Dr. Floyd: [after completing the space station's voice-print identification] See you on the way back.
Mission Controller: X-ray delta one, this is Mission Control. Roger your two-zero-one-three. Sorry you fellows are having a bit of trouble. We are reviewing telemetric information in our mission simulator and will advise. Roger your plan to go EVA and replace alpha-echo-three-five unit prior to failure.
[first lines]
Aries-1B stewardess: Here you are, sir, main level please.
Stewardess: Thank you. You are cleared through Voiceprint Identification.
Dr. Floyd: [upon learning about the monolith while on the moonbus] Deliberately buried. Huh!
Dr. Floyd: I'm sorry, I'm simply not at liberty to say.
HAL: That's a very nice rendering, Dave. I think you've improved a great deal. Can you hold it a bit closer? That's Dr. Hunter, isn't it?
Dr Floyd: Now I'm sure you're all aware of the extremely grave potential for cultural shock and social disorientation contained in this present situation, if the facts were prematurely and suddenly made public without adequate preparation and conditioning.