The dream of generations of Dragonriders draws within reach as, with the aid of an intelligent computer, the possibility of destroying the devastating phenomenon known as ``Thread'' becomes a reality. Having exposed Pern's civilization to technology in Renegades of Pern ( LJ 10/15/89), McCaffrey proceeds with her customary skill and humor to explore all the ramifications of culture shock. Despite some weaknesses in plot and an odd notion of time travel, the latest novel in a popular series will not lack for readers. Especially for libraries owning the previous Pern titles.

YA-- AIVAS, the Artificial Intelligence Voice Address System that was a part of the original colonists' settlement, is unearthed on the Southern continent after having been buried for generations. This latest volume in the Pern saga deals with the reactions of the various lords, dragonriders, and craftsmen as they realize the impact the artificial intelligence will have on their culture and traditions. With its help, F'lar, Robinton, Lessa, Menolly, and all of the other characters YAs have come to care about devise a risky plan to eliminate a serious threat to their environment. While All the Weyrs of Pern is not as tight and exciting as the earlier dragonrider books, it is a well-written novel that's sure to appeal to McCaffrey's many fans.-- John Lawson, Fairfax County Public Library, VA