The Earth, the savannas of equatorial Africa. A small tribe of Pithecanthropus is on the verge of extinction. Nature has not provided them with any powerful fangs nor sharp claws nor quick feet, but in their eyes flicker glimpses of consciousness. Perhaps these qualities have attracted the attention of some highly advanced extraterrestrial civilization, which carefully cultivates seeds of Reason wherever they manage to find it. Pithecanthropus become experimental in a great cosmic experiment.
One night in the river valley appears a lump of completely transparent material. At dusk, when the tribe returns to the caves, unusual rock suddenly utters a strange vibrating sound that attracts Pithecanthropus like a magnet. In the gathering darkness crystal comes alive, it begins to shine and in its depths appear whimsical drawings. Charmed Pithecanthropus do not know that at that moment the machine is exploring their minds, assessing abilities and predicts the possible direction of evolution. Crystal summons of one or the other, and they are, in spite of himself, doing a new movement: the naughty fingers knot the first node on the Earth, the leader picks up a rock and tries to hit the target. Lessons continue every night. During the year, the life of the tribe is changing completely - now Pithecanthropus know how to use a set of simple tools and hunt large animals. Endless hunger and fear of predators retreat into the past, there is a time for thought and imagination. The mysterious monolith disappears as suddenly as it has appeared. His mission is accomplished – on the Earth appears a creature endowed with reason.
It is the XXI century. American researchers have found on the Moon the first irrefutable evidence of the existence of extraterrestrial civilizations.
Urgently called on the Moon the chairman of the National Council of Astronautics learns that magnetic intelligence spotted a strong distortion of the magnetic field in the Tycho crater area, and excavations in the center discovered anomalies in the six-meter depth - a box of perfect proportions of unknown in the world heavy-duty black substance. The most striking thing in this discovery is its age: geological analysis suggests that the monolith has been buried here about three million years ago.
When dawn comes and the black monolith in the first time after three million years of imprisonment catches a sunbeam, a piercing electronic shriek sounds in headsets of standing around people. This signal is traced by space monitors and the central computer, processing the information, concludes: directed energy pulse is clearly artificial, and rushed from the Moon's surface in the direction of Saturn.
All this is known only to a handful of people, because the effects of the shock, which will inevitably have to go through humanity, is unpredictable.
It is an interplanetary space. "Discovery" spaceship. The first months of the flight are in serenity. Two keepers of the crew members - Frank Poole and David Bowman - keep watch on a daily basis, perform everyday duties. The other three are immersed in an artificial hypothermal sleep from which they will awaken only when "Discovery" orbits around Saturn. Only these three know the true purpose of the expedition - possible contact with an extraterrestrial civilization, while Poole and Bowman find flightan ordinary research trip. Those who prepared the expedition, decided that it was necessary for the security and interests of the nation.
In fact, the ship is not run by people, but by the sixth member of the crew, HAL 9000 - the brain and the nervous system of "Discovery". HAL 9000 is created through a process similar to the development of the human brain, it can be called a true thinking machine, and it communicates with people human language. All features of HAL 9000 are intended to perform a set program of the expedition, but the contradiction between the objectives and the need to hide it from the colleagues, gradually destroys the integrity of its "psyche". The machine starts to make mistakes, and finally the crisis comes: overhearing talks of astronauts to the Earth about the necessity to turn the HAL 9000 off, it takes the only possible solution: to get rid of people and finish the expedition by itself. It simulates an aerial accident, and when Frank Poole spacewalks to replace the unit, HAL 9000 kills him by the reactive capsule-boat at full speed flying on the astronaut. And in the next moment, stunned Bowman sees on the screen that the boat is dragging on its tether the body of the deceased friend away from the ship. Frank Poole would be the first person to get to the Saturn.
Bowman tries to wake the sleeping, but hears a sound that made his heart grows cold: it's flap of the outer hatch of the ship openning and the air rushes into the abyss of space. He manages to escape in an emergency chamber, put on a suit and disable higher centers of the electronic brain. He remains alone million kilometers from the Earth. But engines and ship navigation systems are in good repair, the connection with the Earth is restored and the emergency oxygen supply will be enough for him for months. The expedition continues, and Bowman, who is now aware of its ultimate goal, is reaching a dead giant Saturn. He is ordered to start the examination of the eighth satallite of Saturn, Iapetus. The entire surface of the Iapetus, devoid of atmosphere, is black, resembles charcoal - except a white plateau strikingly regular oval with black mark in the center, which is exactly the same black monolith, as on the Moon, just gigantic.
The experiment started three million years ago was completed. The monolith on the Iapetus is Sentinel Stargate - it was set by the same, in no way similar to the human beings, who had sent to the Earth a mysterious crystal and buried a black lump on the Moon. Their efforts were not in vain: the Earth really spawned mind that can reach other planets, and proof of this was the signal of the lunar monolith that sent the message on Iapetus.
David Bowman decides to sit on the Iapetus in the capsule, and its approach awakens forces imprisoned in the Stargate. The upper edge of the black monolith suddenly goes deep and the capsule begins to fall into a bottomless pit. Stargate opened.
Time stops - clock stop counting the seconds - but the perception and consciousness continue to work. Bowman sees black walls of the "mine" and in the lumen myriads of stars, "receding" from the center. He is aware that something inaccessible for his understanding is happening with time and space but has no fear, feeling that he is protected by the infinitely powerful Mind. In the end he finds himself in hundreds of light years from Earth. The capsule tends to a red giant star in the realm of flame, but when the journey ends, Bowman seems that he has gone mad - he was in the ordinary hotel on the Earth. Only after some time he realizes that all this were decorations made for the host guest af a two-year-old TV movie. Bowman goes to bed and falls asleep - for the last time in his life. He merges with the cosmic mind, losing the physical body, acquires the ability to travel through time and space by the effort of thought and saves the planet from the impending nuclear catastrophe.