2061: Odyssey Three
Arthur C. Clarke
 In the previous novel, 2010: Odyssey Two, Jupiter was converted into a mini-sun which was dubbed "Lucifer" following the Soviet ship Leonov’s mission to Jupiter to find out what happened to the Discovery. A message was sent to Earth by Dave Bowman, through HAL: This is due to Lucifer melting the frozen ocean beneath the surface of Europa, causing an atmosphere to form and leading to the discovery of alien life in Europa's ocean. When the Leonov returned to Earth, Heywood Floyd (whose marriage had broken up while he was on the Leonov) suffered an accident. His recovery on an orbital space hospital took longer than expected and he became a permanent resident there after finding that his body could no longer handle Earth-level gravity. His grandson Chris works aboard the spacecraft Galaxy and has not seen his grandfather in years. The black population of South Africa has rebelled in the 2030s and formed the United States of Southern Africa (USSA). The white population fled to Europe, taking most of the country's wealth with them and leaving the black population to rebuild the economy, which they did in a matter of weeks by use of diamonds. (2061 was published in 1987, at which time apartheid was still in force in South Africa.) Large-scale interplanetary travel is now commercially viable with muon-catalyzed fusion-powered spacecraft. On Europa, an enormous mountain has sprung up out of nowhere. No one is sure of the origin of "Mount Zeus"; being asymmetrical, it cannot be a volcano. In 2061, at the age of 103, Floyd is chosen as one of several "celebrity guests" to come aboard the privately owned spaceliner Universe for the first-ever human landing on the surface of Halley's Comet, when it makes its periodic pass through the Solar System. Meanwhile, a team of scientists on Ganymede (formerly a moon of Jupiter that now orbits the star called "Lucifer") is terraforming it for potential habitation. Scientist Rolf van der Berg, a second-generation Afrikaner refugee, studies pictures of Mount Zeus and determines that it is in fact one enormous diamond. He communicates his discovery to his uncle Paul Kreuger; the expedition planners invite van der Berg to join the crew of Galaxy for its flyby of Europa. As Galaxy nears Europa, a stewardess attempts to single-handedly hijack Galaxy, forcing it to crash into Europa's ocean. Her plan having failed (her motivation and loyalties are not explained, but she is assumed to be a militant anti-Afrikaner), she commits suicide. The crew is now stranded, but their sister ship Universe is tasked to rescue her. Van der Berg and Chris Floyd take the shuttle William Tsung (nicknamed Bill Tee) to study Mount Zeus; also the wreck of the Chinese spacecraft Tsien, and the enormous monolith lying on its side at the border between the dayside and nightside, dubbed the "Great Wall". Near Mount Zeus, van der Berg relays the message "LUCY IS HERE" to his uncle Paul, verifying that Mount Zeus is indeed one large diamond. The code word "Lucy" was chosen both in reference to the mini-sun Lucifer and to an article in the journal Nature in 1981 hypothesizing that the cores of Uranus and Neptune were in fact diamonds the size of Earth (caused by the compression of carbon), with the hypothesis making a logical extension to Jupiter. The article was subtitled "Diamonds in the Sky?" in reference to the Beatles song "Lucy in the Sky with Diamonds". Mount Zeus is a fragment of Jupiter's core which survived the creation of Lucifer and later struck Europa. On the Universe, the celebrity guests discuss the mystery surrounding Bowman and the monoliths, and whether they would be allowed to land on Europa to rescue Galaxy’s crew. Floyd follows a suggestion that he simply try to call Bowman on the radio, and that night has a strange dream in which he sees the monolith floating at the foot of his bed. The Bill Tee flies by Tsien, which has been completely stripped of its metals (rare and thus valuable to the Europans), and on to the Great Wall. An image of his grandfather appears to Chris in the same way that Bowman appeared to Floyd in 2010, telling him that the Universe was coming. Universe rescues Galaxys crew; they are brought to Ganymede, where they watch as Mount Zeus, which has been steadily sinking, finally disappears beneath the Europan surface. Kreuger writes a follow-up article for Nature, stating that Mount Zeus was a mere fragment of Jupiter's core and it is almost certain that many more such large pieces of diamond are currently in orbit around Lucifer, and proposing that a program be initiated immediately to collect these enormous quantities of diamond and put them to use. Floyd and Chris become close again, and both become friends with van der Berg. They talk about how Floyd called Bowman on the radio, and Chris asks if Bowman ever replied. Floyd almost tells his grandson about the monolith in his cabin, but does not after rationalizing that it was probably a dream. It was not a dream. The monolith duplicated Floyd's consciousness; there are now two Heywood Floyds, one an immortal being who resides with Bowman and HAL inside the Great Wall. In the epilogue, the star Lucifer stops shining in 3001, and in Manhattan "the monolith awakes" (referring to the original monolith discovered on the moon in 1999, and which was taken to Manhattan as a monument in 2006). It is also indicated that humans have found more quantities of diamond from the former Jupiter and used it to create space elevators and an orbital ring connecting them, as suggested by Kreuger. (This idea will later be a central concept in 3001: The Final Odyssey.)