Anne McCaffrey's beloved science fiction series is set on Pern, a planet colonized by humans who have forgotten their technological origins. The inhabitants survive with the help of dragons genetically engineered to fight Thread, a deadly spore that periodically falls from a neighboring planet and destroys all organic matter it touches. The dragons bond telepathically with their riders, creating partnerships that structure Pernese society. The series spans multiple books written over decades, some with McCaffrey's son Todd. In the books following a devastating plague that kills too many dragons to adequately protect the planet, the protagonists must take extraordinary measures, including manipulating time itself, to undo the damage. The series combines elements of fantasy (dragons, feudal society, heroic quests) with science fiction premises (genetic engineering, interstellar colonization, plausible alien biology). McCaffrey created one of science fiction's most detailed and beloved worlds, populated by characters readers followed across generations. The dragons of Pern, intelligent and emotional creatures who choose their human partners, remain among the genre's most memorable creations.