All the Weyrs of Pern (1991) is the 11th book written in the Dragonriders of Pern series.In chronological order it is one of the stories set during the ninth pass, about 2500 years after landing.

When AIVAS – the Artificial Intelligence Voice Address System – was first discovered at Landing, the enture planet of Pern was awed at the knowledge it divulged. All the history of the people of Pern was there. Dragonholders, Lord Holders and Craftmasters crowded into the tiny inner room to learn the secrets of their beginnings. Ana AIVAS had other gifts to offer – stored information of old crafts that had been forgotten, of medicine, music and technology.

Bu the greatest promise AIVAS offered was the chance to rid Pern of Thread forever. All the great ones of Pern began the long and arduous task of learning just how to operate the incredible plan – a plan of such daring and epic proportions that both dragons and riders would be put at risk.

Author Biography

Anne McCaffrey was one of the world's leading science-fiction writers, and won both the Hugo and Nebula awards as well as the Margaret A. Edwards' Lifetime Achievement Literary Award. Born and raised in the US, although of Irish extraction, she spent the last years of her life in Ireland, in the heart of the Wicklow Mountains. She died in 2011 at the age of eighty-five. She is the creator of the Dragons of Pern series.