All the Weyrs of Pern

All the Weyrs of Pern is a science fiction novel by the American-Irish author Anne McCaffrey. Published in 1991, it was the eleventh book published in the Dragonriders of Pern series. The story follows immediately from the final scene of Renegades of Pern, in which the Admin building from Pern's first generation of colonists is discovered, along with an advanced computer called AIVAS (Artificial Intelligence Voice Address System), at the Landing site that is being excavated. AIVAS has remained undisturbed since the events of Dragonsdawn some 2500 years earlier and, in addition to holding a huge volume of stored information long since lost to the Pernese society, claims to be able to eliminate the threat of Thread forever. The Weyrs, led...