
They genetically modified Pern's native 'fire lizards', creating the fire breathing dragons, saving the day and creating the 'Weyrs' in which the DragonRiders live. The inhabitants of the planet are ex-colonists from Terra who were reduced to the Spartan non-technological lifestyle by the first incursion of the airborne invader. This mindless parasite arrives every 200 years thanks to the close passing of a red star, and destroys whatever it touches before dying itself. For the uninformed, the books are set on the world of Pern, where a select group of citizens ride fire-breathing dragons to shoot a parasitic extra-terrestrial invader known as 'Thread' from the skies. If you've never read an Anne McCaffrey DragonRiders of Pern book, chances are that you either a) hate fantasy literature, or b) have been living under a rock for the last 30 years.
