" This picks up a few years after the end of The White Dragon. (the books' internal dates would probably indicate what the gap separating the two is, and I'm sure fans have it calculated to the day, but I can't be bothered) The advanced computer AIVAS has guided the inhabitants of Pern in recovering the technology available to their predecessors who landed on the planet over 2500 years previously; this suits most Pernese quite well, but a few resent the machine which they call "Abomination". Despite these naysayers' efforts, AIVAS engineers the end of Thread on Pern through two methods: a) moving the Red Star's orbit such that it will no longer pass through the Oort cloud and b) creating a parasite which will destroy Thread at its source, ensuring that the threat will never recur. This and the death of (retired) Masterharper Robinton ends an era on Pern...and, frankly, I think this book should have ended the series of Pern books, although the dedicated fans think otherwise. "
— Josephine, 1/19/2014