Robots and Empire
Isaac Asimov
 The Earthman Elijah Baley (the detective hero of the previous Robot books), has died nearly two centuries earlier. During these two centuries, the balance of forces in the galaxy has changed dramatically. Inspired partly by Baley's adventures in space (on the "Spacer" worlds of Solaria and Aurora), Earth-people have overcome their stagnation and agoraphobia, and embarked on a new wave of space colonization, using faster-than-light drive to reach distant planets throughout the Milky Way Galaxy, beyond the earlier "Spacer" worlds. These newly colonized worlds are clearly distinct from the earlier "Spacer" ones, and their inhabitants, calling themselves "Settlers" rather than "Spacers", revere Earth as their mother-world. Meanwhile, Baley's memory remains in the mind of his former lover, Gladia Delmarre, a "Spacer", who has a centuries-long lifespan, as opposed to the seven or eight decades that Earth people (such as Baley) live. It is discovered that Solaria, the homeworld of Gladia, and the 50th-established of the Spacer planets, has been abandoned and has become empty of all inhabitants (except for millions of robot servants, which have been left behind). Gladia then meets a seventh-generation descendant of Baley's, Daneel Giskard (or D.G.) Baley, a Settler-Trader. He asks for Gladia's help in visiting Solaria, in order to unravel the mysterious destruction of several "Settler" spaceships making landings there, and also with the mission of reclaiming the abandoned robots. Gladia agrees to go, and is accompanied by the positronic robots R. Daneel Olivaw and R. Giskard Reventlov. [R. Giskard has secret telepathic powers about which only R. Daneel knows.] These robots are both the former property of their creator, Dr. Han Fastolfe, who bequeathed them to Gladia in his will. At the same time, Daneel and Giskard are engaged in a struggle of wits with Fastolfe's bitter archrivals, the roboticists Kelden Amadiro and Vasilia Aliena, Fastolfe's estranged daughter. Whereas Fastolfe supported the expansion of the "Settler" population from Earth, Amadiro detests all Settlers - as do most "Spacers", who consider all Earthlings to be little better than barbarians. Amadiro wants to see the Earthlings destroyed, so that the descendants of the Spacers alone can inherit the Milky Way (There are no other intelligent beings in Asimov's fictional galaxy). However, for many decades Amadiro has been continually thwarted in introducing an anti-Settler policy into the governments of the Spacers. These blockings of Amadiro's plans have been largely caused by the telepathic manipulation of key people by R. Giskard. Frustrated by his series of failures, Amadiro decides to accept an ambitious and unscrupulous apprentice, Levular Mandamus. Mandamus develops a cruel plan to destroy the population of the Earth, using a newly-developed weapon, the "nuclear intensifier". Amadiro and Mandamus intend to kill the population of the Earth and to make the Earth uninhabitable for human beings by using radioactivity. They intend to use the nuclear intensifier device to speed up all of the natural radioactive decay processes in the upper crust of the Earth, thereby making the surface of the Earth massively radioactive. [Note: At the time of Asimov's writing, there had been the recent discovery of the W particle, which is the force carrier of the weak nuclear force. This force is responsible for most forms of nuclear decay: alpha emission and beta emission. The hypothetical "nuclear intensifier" would work by emitting large numbers of W particles, hence expediting nuclear decay.] While Amadiro schemes, R. Daneel and R. Giskard slowly assemble the pieces of the roboticists' genocidal plan for mass murder. The robots, sharing Fastolfe's humane vision of a unified Settler/Spacer Galaxy - or, failing that, a Galaxy where Settlers can thrive in spite of Spacer domination - attempt to stop Amadiro. However, Daneel and Giskard are hampered by the Three Laws of Robotics, in particular, by the First Law of Robotics, which prevents them from making any direct attack on Amadiro. Daneel, meanwhile, has formulated an additional Zeroth Law of Robotics, which he thinks might help them to override the First Law, and to save the population of the Earth. The robots must work their way through the ramifications of the First Law and the Zeroth Law, in a race against time, before they face a confrontation with Amadiro and Mandamus. Fastolfe's brilliant daughter Vasilia has long coveted the valuable Giskard, and she finally determines to take him away from Gladia. Then, when Vasilia deduces that Giskard has telepathy, she confronts him with this fact. Giskard is compelled to manipulate her mind telepathically in order to make her forget about his telepathic powers. This leaves the two positronic robots free to deal with Amadiro. The two robots locate Amadiro and Mandamus on Earth, where they find the two Spacers debating the best way to use the nuclear intensifier for their ghoulish purposes. (They just happen to be at the site of Three Mile Island in Pennsylvania). After Amadiro admits to the robots their plans to carry out mass murder on the Earth, Giskard decides that it is necessary to tamper with Amadiro's brain (using the newly-created Zeroth Law). Unfortunately, the way that Giskard does this causes irreversible damage to Amadiro's brain - and thus harm to him, as is forbidden by the First Law. Giskard is mentally "skating on thin ice" in this regard - and he is not far from suffering the consequences of such action. Now standing alone with the robots, Mandamus claims that his intentions regarding the nuclear intensifier were more benign than Amadiro's. Mandamus wants to draw out the radioactive catastrophe over many decades, rather than the mere years that Amadiro wanted, so that Amadiro could draw evil pleasure from the destruction of the Earth's population within his own lifetime. Giskard decides that it would be best for humanity to abandon the Earth, hence he allows Mandamus to adjust the settings of the nuclear intensifier. He extends the time scale of the radioactive catastrophe to 150 years, allowing humanity to evacuate the Earth (though a significant population still dwells there at the time of the novel Pebble in the Sky). Next, Giskard tampers with Mandamus's mind as well, ensuring that Mandamus will have no memory of what has happened. Giskard predicts, correctly, that by forcing humanity's hand into leaving the Earth, vigor will be reintroduced into mankind and the new Settlers will spread out across space at a rate never before seen. This will continue until all the governments of the interstellar colonies decide to unite into one "Galactic Empire". However, by allowing Mandamus to proceed with his original plan, Giskard becomes instrumental in creating a very radioactive planet Earth, and hence placing the inhabitants of Earth under grave threat of death. This contradicts the First Law of Robotics. The Zeroth Law does not prove to be enough, to Giskard at least, to justify harming humans for the sake of a hypothetical future benefit. Under the stress of changing the course of humanity, R. Giskard himself suffers a cascading and soon-fatal malfunction of his positronic brain. This is because he is not sure whether his actions will bring about an ultimate victory for the Spacers, leading to the final death of humanity. However before R. Giskard's brain freezes, he confers his telepathic ability upon R. Daneel, and Daneel takes on the heavy burden of guiding the entire burgeoning Galactic civilization.