story, and a consensus developed that the first version is superior. Thus, in continuing Alvin’s story, writer Gregory Benford chose to follow the original version, republished together with Benford’s sequel asBeyond the Fall of Night in 1990.

Childhood’s End

Considered by many to be Clarke’s masterpiece, Childhood’s End begins when Earth is peacefully taken over by the benevolent alien Overlords. Concealing themselves because they resemble devils, the Overlords govern through human intermediaries such as the secretary-general of the United Nations, whom they effortlessly rescue when he is kidnapped by rebels who oppose the Overlords. When they finally reveal their appearance fifty years later, humanity is enjoying a golden age of peace and prosperity thanks to the Overlords’ wise rule and advanced technology. Streaks of rebelliousness persist, however, and a man named Jan Rodricks stows away on a starship to visit the Overlords’ home world. Later, on Earth, George and Jean Greggson are upset when their son begins dreaming about other worlds and their daughter manifests telekinetic powers. An Overlord now explains the true motives behind their takeover. Certain races, such as humans, have the capacity to achieve a higher level of evolution by merging into a group mind and joining the mysterious Overmind that controls the universe; the Overmind assigns the Overlords, who paradoxically lack this potential, to supervise these races during the transitional stage. Soon, all human children have mentally united and seem like aliens to their distraught parents. While the adults, their dreams shattered, commit suicide in various ways, Rodricks returns to Earth to observe its final moments, as the children employ psychic powers to disintegrate their world and merge with the Overmind.

Perhaps perturbed by his own prophecy, Clarke adds this introductory comment: “The opinions expressed in this book are not those of the author.” Certainly, Childhood’s End stirs strong and conflicting emotions in its final portrait of Earth’s children seemingly reduced to naked savages engaged in senseless activities, even while the reader is assured that they represent a glorious new stage in human evolution. If not wholly satisfactory in style and character development, the novel persuasively presents its unsettling developments and, decades after publication, continues to inspire heated discussion.

2001: A Space Odyssey

Clarke’s novel 2001: A Space Odyssey differs from the film based on it both in major details and in its overall tone, which is clear and explanatory, in contrast to Kubrick’s directorial mystification. Clarke develops the character of Moon-Watcher, the ape-man of the distant past who first notices the alien monolith that teaches Moon-Watcher and his companions to use tools. Next, in the near future, Heywood Floyd visits the Moon to examine another monolith, which suddenly emits a powerful radio signal toward Saturn (not Jupiter, as in the film). The spaceship Discovery is sent to investigate, though the crewmen who are not placed in hibernation, David Bowman and Frank Poole, know nothing about the monolith. Driven insane by contradictory commands to cooperate with Bowman and Poole while concealing their real mission, the onboard computer HAL kills Poole in space and attempts to kill Bowman by opening the ship’s air locks, exposing him to the vacuum of space. Bowman finds an emergency shelter with a spacesuit, disables HAL, and proceeds to Saturn, where another monolith waits on the surface of Saturn’s moon Japetus. An alien transportation system then takes Bowman to a distant planet and a crude replica of an Earth hotel, where he is transformed into a baby with immense powers who returns to Earth and destroys its nuclear weapons.

Critics agree that 2001 stands on its own as a masterful saga of human evolution and exploration; the later sequels do not enhance its impact, however. In 2010: Odyssey Two, Floyd returns to Jupiter (following the film version) to discover Bowman’s fate, meets a ghostly Bowman (now cast more as a messenger for the aliens than as the harbinger of a new human race), and flees when Jupiter becomes a star, with its moons offered to humanity as new homes (except Europa, declared off-limits by the aliens). In 2061: Odyssey Three, Floyd journeys to Halley’s comet but accidentally lands on Europa, and in 3001: The Final Odyssey, a revived Poole helps to disable the monoliths, now likened to out-of-control computers. Although readers may enjoy meeting old friends, the sequels to 2001 never reveal the unseen aliens or their final plans for humanity, which is perhaps as it should be.

Rendezvous with Rama

Clarke’s first novel after 2001 begins with the discovery of a gigantic cylindrical object, clearly artificial in origin, approaching the Sun. William Norton, commanding the spaceship Endeavour, leads an investigation of the object, named Rama. Entering through an airlock, Norton and his crew observe a huge interior landscape divided by the Cylindrical Sea, with clusters of buildings dubbed “cities” and other inexplicable objects. As they descend to the surface, massive lights suddenly illuminate Rama, as if it were coming to life. When a crewman crosses the Cylindrical Sea in a glider and investigates strange formations, he notices the first of many “biots”—biological robots manufactured to perform functions such as observation and removal of debris. The people of Mercury, fearing Rama is hostile, launch a nuclear missile to destroy it, but another crewman disables the bomb. As the humans depart, the biots destroy themselves and the lights go out, signaling that Rama has finished its work. Rama then absorbs energy and matter from the Sun before leaving the solar system—though a scientist notes, “The Ramans do everything in threes,” suggesting other alien vehicles may arrive soon.

Despite the novel’s weak characterization, Clarke’s unique ability to evoke the bizarre with straightforwardexposition is well displayed in this story, which intrigues readers with its narrative unpredictability and unanswered questions. Rendezvous with Rama earned both the Hugo Award and the Nebula Award as the best science-fiction novel of 1973. Clarke later continued the story in three sequels cowritten with Gentry Lee—Rama II, The Garden of Rama, and Rama Revealed—describing the coming of another Raman spaceship and the astronauts who stay on board for a cosmic journey. Despite revealing new information about the Ramans and their goals, the sequels leave many mysteries unresolved, ultimately adding little to the original novel.

The Fountains of Paradise

Projected as the capstone of Clarke’s career, The Fountains of Paradise describes a future engineer, Vannevar Morgan, planning to construct an enormous “space elevator” to connect the surface of Earth to a geosynchronous satellite, providing cheap and safe transportation into space. His story is interwoven with that of another great builder, Kalidasa, the ancient king of Taprobane (an island analogous to Sri Lanka) who built the magnificent Fountains of Paradise at the mountain where Morgan wishes to build his space elevator. When the monks inhabiting the mountain abandon their home after an old prophecy is fulfilled, Morgan begins work, and soon the tower is slowly being constructed from a point between Earth and space. When scientists are stranded on the incomplete tower, Morgan pilots a transport vehicle to bring supplies, though the effort strains his weak heart and causes his death. In an epilogue set further in the future, an alien visiting Earth marvels at its “Ring City,” with Morgan’s tower as only one spoke in an immense wheel of satellites circling the globe, all linked to each other and to the ground.

Inspired by the history and traditions of Sri Lanka, Clarke’s adopted homeland, The Fountains of Paradise seems one of his most personal works, blending reverence for ancient accomplishments with dreams of futuristic space exploration. Like Rendezvous with Rama, it earned both the Hugo Award and the Nebula Award. The concluding chapters describing Morgan’s rescue may be the most gripping sequence Clarke ever wrote, but its awe-inspiring vision of a world transformed by cosmic engineering is what makes the novel memorable.

Time Odyssey trilogy

The Time Odyssey trilogy—comprising Time’s Eye, Sunstorm, and Firstborn, all cowritten with Stephen Baxter—stands out among Clarke’s collaborations because of its relationship to 2001; not a sequel or prequel, it is what the authors term an “orthoquel,” employing the premise of 2001—unseen aliens enigmatically manipulating human destiny—to develop an entirely different narrative. Here, the aliens’ presence is represented not by monoliths but by “Eyes”—floating spheres, detached from our own reality, that observe and sometimes interact with our universe—and the aliens’ purpose is unambiguously inimical: Believing that the survival of life in the cosmos depends on strict conservation of energy, they eliminate intelligent civilizations that consume too much of it.

In Time’s Eye, aliens slice small regions of Earth from various past and present eras and assemble them as a new world, called Mir, presumably to preserve and study, in a separate universe, the species they will destroy. United Nations peacekeepers and astronauts from the year 2037, then, find themselves in a world with australopithecines, Neanderthals, the armies of Alexander the Great and Genghis Khan, and nineteenth century British soldiers accompanied by young Rudyard Kipling. One peacekeeper, a woman named Bisesa Dutt, develops a strange rapport with one immense Eye that eventually transports her back to her own world, where she arrives one day after her initial disappearance.

In Sunstorm, Bisesa learns that an immense burst of energy from the Sun, which had catastrophic results, was only the prelude to an even more massive sunstorm that will effectively eliminate all life on Earth. Her suspicion that this impending doom has been caused by aliens is confirmed by evidence that a gigantic planet was deliberately smashed into the Sun long ago, setting in motion disturbances that will eventually trigger the sunstorm. The only way to save humanity, as explained by the artificial intelligence Thales, is to construct a huge, ultrathin “shield” to divert some harmful radiation away from Earth. Humans work valiantly and succeed in constructing the necessary shield, which reduces the scale of the disaster so that “only” one-tenth of their race is killed.

In Firstborn, the thwarted Firstborn launch another attack, a “Q-bomb” aimed at Earth that will employ quantum energy to devastate the planet. Scientists on Mars, however, discover an Eye apparently trapped within an energy field by the extinct Martian race, which battled the Firstborn before being destroyed by them. Mysteriously returned to Mir, Bisesa uses an idea from Thomas Alva Edison to send a message to a surviving Martian in that world’s universe, and the Martian contrives to disturb the Eye further. This inspires the Q-bomb to change course to destroy Mars instead of Earth, again saving humanity. In an epilogue, Bisesa meets a member of another race, called the Lastborn, that is desperately struggling against the Firstborn.

In some respects, the Time Odyssey trilogy seems an ideal melding of Clarke’s visionary ideas and Baxter’s ability to convey those ideas with more involving characters and dramatic activities than are often found in Clarke’s works. Like Clarke’s own continuations of 2001, however, the trilogy is ultimately disappointing because it again fails to explain its aliens fully or to conclude their story clearly, making the entire saga exciting but pointless.

The Last Theorem

Clarke’s final novel involves a Sri Lankan college student, Ranjit Subramanian, who dreams of rediscovering Fermat’s own proof of his famous theorem. A chance encounter with a family friend brings Ranjit into the company of seagoing pirates, leading to his arrest and torture. During the ordeal, however, he somehow manages to figure out the proof, which he carries in his mind until he is released and can finally write it down and publish it. Ranjit then achieves worldwide fame and a lifetime professorship at a Sri Lankan university, where he settles down to a satisfying life of teaching and raising two children with his wife. All the while, enigmatic aliens known as the Grand Galactics, having detected signs of destructive technology on Earth, have dispatched client races to exterminate the human species. As Ranjit observes events from his privileged position, however, humanity finally seems on the verge of achieving lasting peace: An international project known as Silent Thunder peacefully stymies hostile nations by employing electromagnetic radiation to disable all their equipment, and a newly constructed space elevator will finally grant humanity easy access to other planets. A visiting Grand Galactic, perhaps impressed by all this, cancels the order to destroy humanity, though this requires first contact with Earth and an emergency landing by the aliens recruited to destroy humanity; an attempt by diehard American militarists to attack the unthreatening aliens is effortlessly repelled. New technology introduced to Earth by another client race then allows Ranjit’s wife and later Ranjit himself to achieve immortality by being converted into computer programs. An epilogue set in the far future reveals that the Grand Galactics, dissatisfied with their own stewardship of the galaxy, have bequeathed all responsibility for its affairs to another species, the human race.

The Last Theorem might be regarded as a summary of Clarke’s career, bringing together familiar items of careful prediction (such as a space elevator similar to that of The Fountains of Paradise and spaceships with solar sails as seen in his 1964 story “The Wind from the Sun”) with expansive visions of highly advanced, mysterious aliens meddling in human affairs—although some touches, like the business of converting humans into computer programs, seem more a reflection of Pohl’s influence. It is also significant that, in contrast to previous works that convey a certain degree of pessimism regarding humanity’s ability to prosper and endure in a staggeringly vast and often inimical cosmos, Clarke concluded his career with his most optimistic prediction, as humanity not only achieves a genuine utopia on Earth but also eventually becomes the true master of the universe. Still, The Last Theorem cannot be regarded as Clarke’s final masterpiece, as its disparate elements do not always blend well together; in particular, the titular proof ultimately seems inconsequential, important only because it elevates an appealing protagonist to a status that makes him a better witness to key developments in humanity’s future.