There is a small rogue planet that is in a cometary orbit around Rukhbat, going through the Oort Cloud and into conjunction with Pern every 200+ years (or Turns, to the Pernese), dragging material from the Oort Cloud with it, which includes the spores of a deadly fungus, called Thread by the Pernese inhabitants, because of the fact it looks like grey threads when it falls. It rapidly eats anything organic that it contacts.

A deadly rain of Thread falls across Pern for fifty "Turns" as Pern goes through the trail of material left by the rogue planet, known as the "Red Star". Sometimes there are long "Intervals" (the spaces of time between times of "fall") that last four hundred Turns, and the people of Pern believe that there will be no more. We are now in the middle of a time of Threadfall.

Geneticists among the people who originally colonized Pern developed dragons from their smaller cousins, known as fire lizards or flitts. The Pernese dragons are warm-blooded and have soft suede-like hides. They are intelligent, though their memories aren't the best. Dragons teleport any place that their rider has been. They can talk in the minds of their riders at any time. Dragons can talk to anyone they wish but usually only talk to their riders. Once in a while someone is found who can hear and talk to all dragons.

They chew a phosphine rock and exhale a gas that turns to fire when it comes into contact with air. Cold freezes Thread to a black dust, fire burns it to ash, and water drowns it. A certain species of grubs eats it, so do fish, and fire lizards have been described eating it in the books.

The dragons, at the time they hatch, pick their riders from a group of young people that are picked out by adult dragons who have gone on "Search" looking through the crafthalls and the holds and everywhere for more people. The bonding is permanent and is almost on the level of symbiosis. The dragon cannot live without the rider and the rider does not wish to live without the dragon though there are many cases where riders have survived the death of their dragon. They go through a training period during which their dragons grow and learn, then go to work as dragonriders. Golds and greens are females, bronzes, browns and blues are male. Golds are fertile and only mate with browns and bronzes as the blues don't have the stamina to last a full flight. Greens are not fertile and mate with any male dragon who can catch them. Greens are fighting dragons and are infertile, chewing firestone (the phosphine-bearing rock mentioned) and make up about half the strength of the weyrs wings.

The crafts go on the old system of apprentice- journeyman-master, (Guilds) which works best in this society. The Holds are much like feudal fiefs, with the lesser vassals and finally peasants in their cotholds. Thread does not eat through stone, or metal so all buildings are made of it or built into cliffs, windows have metal shutters to cover them during Threadfall.

-written by Amy Miller 
edited by Barbara Huguley

last edit 3/06 - Caryn