David Starr, Space Ranger
Isaac Asimov
 David Starr, Space Ranger introduces the series' setting and the main characters. The novel is set around A.D. 7,000 (five thousand years after the first nuclear bomb, as stated at the beginning), when humanity has spread among the worlds of the Solar System as well as planets orbiting other stars. The most powerful organization in the Solar System is the Council of Science, which suppresses threats to the System's people. Protagonist David Starr is an orphaned biophysicist qualified for membership in the Council of Science, who learns from his guardians Augustus Henree and Hector Conway of some 200 deaths in the last four months, whose victims died while eating produce raised on Mars. Conway and Henree fear that the deaths are part of a conspiracy to frighten the people of Earth; wherefore Starr travels undercover to Mars to discover the deaths' connection to the Martian Farming Syndicates. On Mars, Starr meets John "Bigman" Jones, a bellicose 5'2" Martian farmboy blacklisted at the Farming Syndicates for seeing something forbidden him. When his former boss Hennes orders Jones out of the Farm Employment Building, Starr intervenes, and gains positions for both himself and Bigman. Later, Hennes has Starr and Bigman stunned. Starr wakes in the farm owned by Hennes' boss, Mr. Makian, to whom he gives the alias Williams, and states that he came to Mars explain a younger sister's death of food poisoning; wherefore Makian sends the farm's agronomist Benson to speak with him. According to Benson, the poisoned food came from several Martian farms, but was exported through Wingrad City, one of three domed human settlements on Mars; whereas Makian and several other farm owners have been offered ridiculously small sums of money for their farms, apparently without connection to the poisonings. Benson suggests also that intelligent native Martians living below the planet's surface are poisoning the food in order to drive humanity from Mars. Makian offers to let Starr join a survey of the farmlands. Bigman warns him that Hennes will attack him during the survey; but when Starr decides to take part anyway, Bigman joins him. As he enters Martian gravity, Starr loses control of his sand-car, nearly sending it over a crevasse; whereupon Bigman discovers that Starr's sand-car is missing its weights, and Starr realizes that Griswold deliberately failed to warn him. He then confronts Griswold, who in the struggle falls into the crevasse and dies. The next day, Benson makes Starr his assistant, to keep him from Hennes. When Bigman receives his references from Hennes and takes his leave, Starr asks him to obtain some book-tapes from the library at Wingrad City. Bigman agrees, then admits that he has recognized the pretended 'Williams' as David Starr of the Council of Science. When Starr meets Bigman that night outside the dome, he reveals that he believes in Benson's Martians, and that the crevasse into which Griswold fell is an entrance to their caverns. Starr descends into the crevasse and is captured by the Martians;–––disembodied intelligences curious about the Earthmen on the surface, and who know nothing of the poisoned food. They give Starr the name 'Space Ranger' because he travels through space, and give him an immaterial mask that will act as a personal force field and disguise him from other humans. Starr uses the mask to shield himself from a Martian dust storm as he returns to Makian's farm, where he is questioned how he survived the storm and answers (truthfully) that he was returned by a masked man called the Space Ranger. Benson tells him that while he was gone, all the farm owners received a letter from the poisoner, who claims that unless the farm owners surrender control to him within thirty-six hours, the poisoner will increase the amount of poisoned food a thousandfold. After Benson leaves, another of Hennes' minions tries to shoot Starr. Later, Hennes accuses Starr of poisoning the food; whereupon Bigman enters with Dr. Silvers of the Council of Science, who announces that the government has declared a System Emergency and that the Council will take control of all the farms on Mars. If the mystery is not solved by the time the deadline expires, all Martian food exports to Earth will stop, and food rationing will be instituted. Starr arranges with Silvers to be publicly removed from the Makian farm, then allowed to secretly return. Disguised by his mask, he confronts Hennes, who blinds himself firing a blaster at him; searches Hennes; and, once undisguised, persuades Silvers to meet with Makian, Hennes, and Benson the next day. At the meeting, Starr appears in disguise and reveals that Benson poisoned the food while pretending to take samples of it, while Hennes kept in contact with Benson's henchmen in the Asteroid Belt. Following Benson's confession, Bigman reveals that despite the disguise of the Martian mask, he recognized Starr by his uniquely colorless black-and-white boots.