At the Dawn of Man, a group of hominids encounters a mysterious black monolith that is alien to their surroundings. A hominid discovers the first weapon, using a bone to kill prey. The bone is tossed in the air and it's a 21st century spacecraft hovering over the Earth, skipping ahead millions of years in technological development only to imply that man hasn't advanced very far at all psychologically. U.S. scientist Dr. Heywood Floyd travels to the moon to check out the discovery of a strange object on the moon's surface: a black monolith. As the sun's rays strike the stone, however, it emits a piercing, deafening sound that fills the investigators' headphones and stops them in their path. Cutting ahead 18 months, impassive astronauts David Bowman and Frank Poole head toward Jupiter on the space ship Discovery, their only company three hibernating astronauts and the vocal, man-made HAL 9000 computer running the entire ship. When the all-too-human HAL malfunctions, however, he tries to murder the astronauts to cover his error, forcing Bowman to defend himself the only way he can. Free of HAL, and finally informed of the voyage's purpose by a recording from Floyd, Bowman journeys to "Jupiter and Beyond the Infinite," through the psychedelic slit-scan star-gate to an 18th century room, and the completion of the monolith's evolutionary mission.