The background to the Lensman series is a cataclysmic coalescence of two galaxies in the distant past, which precipitated a conflict between the humanoid Arisians and the monstrous Eddorians. The two races began a long war for control of the many new planets spawned by the coalescence. The Arisians planned to build a galaxywide civilization, while the Eddorians sought to subjugate all worlds to their totalitarian rule. An Arisian group mind named Mentor initiated and supervised a special breeding program intended to produce beings capable of battling the Eddorians, using the human inhabitants of Earth as raw material.
After brief interludes set in Atlantis, Rome, and the arenas of three world wars, Triplanetary describes the Eddore-inspired assault led by the Adepts of Jupiter against the human-dominated inner planets of the solar system. The assault causes the planets to unite and, after their victory, to make plans for human expansion into the galaxy. In First Lensman, humans make contact with Arisia, where Mentor arranges that Virgil Samms, the founder of the Galactic Patrol, comes into possession of the Lens, a device that serves as a universal translator. Each individual lens is a semiliving entity attuned to a single wearer. It defies all attempts at analysis or duplication. Armed with lenses, the elite members of the Galactic Patrol fight against the various criminal activities inspired and organized by Eddore’s agents....
(The entire section is 573 words.)