Nine years ago, the American Discovery One's mission to Jupiter mysteriously failed. As depicted in 2001: A Space Odyssey, Discovery's HAL 9000 computer "Hal" (Douglas Rain) malfunctioned, killing four astronauts. The fifth, David Bowman, disappeared into a large, alien Monolith orbiting the planet.
Dave Bowman: My God! It's full of stars!
Heywood Floyd (Roy Scheider), head of the National Council on Astronautics, received the blame for the failure and left NCA. Although tension is growing between the United States and the Soviet Union, both nations prepare missions to determine what happened to Discovery.
Although the Soviet Alexei Leonov will be ready before the American spaceship, the Soviets need American astronauts to help investigate Hal's malfunction and to board an American spacecraft.
Victor Milson: So, here we are on your actual brink. My agency's going to become a part of the military, I've got a president with his finger poised on the button, and you want me to walk across the park and tell him we want to hitch a ride with those very same Russians. Have I missed anything?
Heywood Floyd: That's about it.
The US government agrees to a joint mission since Discovery's orbit is deteriorating and it will crash into Jovian moon Io before the US ship is ready.
Caroline Floyd: I want to be grown-up and understanding about all this, I really do... I try so hard, but I can't. This won't bring those men back. You've been killing yourself over something you did, or something you didn't do right, and now you're looking for absolution... You know, you could get yourself killed.
Heywood Floyd: I'll be scared enough for both of us.
Floyd, Discovery designer Walter Curnow (John Lithgow), and HAL 9000 creator Chandra (Bob Balaban) join the Russian mission.
Upon Leonov's arrival in the Jovian system, captain Tanya Kirbuk (Helen Mirren) and the other Soviets wake Floyd early from his hibernation . . .
Heywood Floyd: All right, what's going on here?
Tanya Kirbuk: What do you mean?
Heywood Floyd: Well, I may not be the swiftest guy in the world, even when I'm not hung over, but I do seem to remember a process where you people ask me questions and I give you answers and then I ask questions and you give me answers and that's the way we find out things. I think I read that in a manual somewhere.
Tanya Kirbuk: Your government wanted us to awaken you when we reported our findings. We did that. You are here to help us reactivate the Discovery and its computer systems because that is United States territory. You are authorized to observe other aspects of our mission. We have no other obligation.
Maxim Brajlovsky: A lot has happened while you have been asleep.
Vasili Orlov: It is not our choice.
Tanya Kirbuk: The problem in Central America is growing worse.
Heywood Floyd: This looks as if you've detected the presence of chlorophyll.
Tanya Kirbuk [interrupts him]: The United States is threatening a naval blockade.
Heywood Floyd [interrupts her in turn]: There's nothing but ice down there so how can there be any chlorophyll?
Tanya Kirbuk [interrupts him again]: You know and I know that my country cannot allow a blockade.
Heywood Floyd: How fast it is moving?
Tanya Kirbuk [continues to talk over him]: We are under instruction...
Heywood Floyd: Listen, just because our governments are behaving like asses doesn't mean we have to. We're supposed to be scientists, not politicians, how fast?
Tanya Kirbuk: Doctor Floyd, I am also an officer of the Soviet Air Force...
Heywood Floyd: HOW FAST?
Vasili Orlov: One meter per minute.
Heywood Floyd: Don't worry, I'm just observing.
Heywood Floyd: Toward the sun?
Vasili Orlov: Yes.
Heywood Floyd: That's incredible.
Tanya Kirbuk: We are going to send a probe down.
Heywood Floyd: GOOD.
A burst of electromagnetic radiation destroys an unmanned probe from Leonov and all telemetry records before the probe takes close-up pictures.
Floyd suspects that it is a warning to keep away from Europa.
Heywood Floyd: Dear Caroline: I miss you terribly. The time has come to put ourselves in an orbit around Io, which is where Discovery is. We don't have enough fuel to slow ourselves down, so we are about to use a technique called aerobraking. The theory is, we will enter the outer layer of Jupiter's atmosphere using what is called a "ballute" for a shield.
The atmosphere will slow us down, and Jupiter's gravity will grab hold of us and slingshot us around behind the dark side. If all goes well, we'll wind up in a gentle orbit around Io. It's dynamite on paper. Of course the people who came up with the numbers on the paper aren't here. Since no one has ever done this before, everyone up here is as scared as I am. The difference is, they're busy. I have nothing to do but wait for it to happen. I hope this is all worth it.
The crew survives a dangerous aerobraking through Jupiter's atmosphere.
Leonov finds Discovery abandoned but undamaged, orbiting the planet close to Io, rotating on an axis at the center of it's spine.
Curnow travels with Cosmonaut Max Brailovsky, and the two, in a risky EVA, enter the spinning ship.
Walter Curnow: I feel so stupid. How do you say, 'stupid'?
Maxim Brajlovsky: Durak!
Walter Curnow: That's me.
Maxim Brajlovsky: You shouldn't feel like that. The same thing happened to me the first time I did this.
Walter Curnow: When have you ever done this before?
Maxim Brajlovsky: Never!
Curnow reactivates the ship and Chandra restarts Hal, which Bowman had deactivated before Discovery arrived at Jupiter.
Chandra inserts two of HAL's modules and activates his console.
Chandra: This is initial voice-logic reconstruction test number one. Diagnostics on voice recognition and speech synthesis centers has been completed. At this level all functions appear normal.
Chandra [while typing]: Hello. Doctor. Name. Continue. Yesterday. Tomorrow.
HAL-9000 [mechanically primitive voice synthesis]: HE-EL-LO-O. DO-OC-TE-ER. NA-AI-ME. CO-ON-TI-IN-NU-UE-YE-ES TU-UR-DA-AY, TO-O-O-MO-OR-RR-O-OW.
Chandra inserts two more modules and hits a key to repeat the voice test.
HAL-9000 [sepulchrally]: Hello. Doctor. Name, continue, yesterday. Tomorrow?
Chandra inserts two more modules and repeats the voice test.
HAL-9000 [almost normal]: Hello? Doctor? Name? Continue? Yesterday? Tomorrow?
Chandra inserts two more modules.
HAL-9000 [mechanically and rapidly, rising in pitch and speed]: Hello doctor name continue yesterday tomorrow . . . hello doctor name continue yesterday tomorrow . . . hello doctor name continue yesterday tomorrow . . . hello doctor name continue yesterday tomorrow . . . hello doctor name continue yesterday tomorrow . . . hellrot inyettyelrot inyettyelrot inyettyelrot inyettyelrot inyetelrot inyet...
Chandra clears the voice test, inserts the last four modules, and hits a key.
HAL-9000 [perfectly normal]: Good morning, Dr. Chandra. This is HAL. I'm ready for my first lesson.
Chandra turns and paternally pats HAL's "eye".
Heywood Floyd [referencing Discovery's schematic diagrams]: Are these the power connections for all the control-based circuits?
Walter Curnow: Most of them, yeah.
Heywood Floyd: What other ones are there?
Walter Curnow: Well, all the environmental controls are fed with this one here...
Heywood Floyd: Yeah yeah yeah, but this is the one that feeds into HAL, right?
Walter Curnow: Right.
Heywood Floyd: Okay... I want you to install this little beauty... right about... there. Just inside the cable trunking.
Heywood Floyd [hands a small device to Curnow]: I want you to put it where no one can find it without a deliberate search.
Walter Curnow: No shit?
Heywood Floyd: No shit.
Walter Curnow: This is pretty sweet... Non-conducting blade, so there won't be any short-circuits when you trigger it... Where's the remote control?
Heywood Floyd: If I trigger it. The control's in my compartment. Little red calculator? You've seen it. You put in nine '9s'. Take the square root, and then hit 'Integer.' In an emergency, even you could do it.
Walter Curnow: What kind of emergency?
Heywood Floyd [holds up the device]: Well if I knew that, I wouldn't need this stupid thing now, would I?
Walter Curnow: Y'know, Chandra'd have kittens if he found out.
Heywood Floyd: Yeah. But he isn't gonna find out, is he.
Walter Curnow: Not from me. They could tear off my fingernails, I won't talk.
Heywood Floyd: Good. Install it tonight when he's asleep. If he ever does sleep.
Walter Curnow: How can you tell?