This book takes place two thousand years after the colonists settle on Pern. Society has crumbled, de-evolving from a sophisticatced technocracy, to a medieval setting. All of that changes when they find an artifact left over from their answers, an artificial intelligence voice activated system, called, what else? AIVAS.
Many of the Pernians are very suspicious of AIVAS, and call it the abomination. A lot of the craftsmen are jealous, because AIVAS is teaching people better ways of working glass and metal, rendering their jealously guarded techniques obsolete. Most of the dissenters are old people, though, and their grumbling comments and petty slights, while annoying, are ignored with some effort.
But when the technology in AIVAS's database starts to revolutionize Landing, many people start to get frightened. Electronics, microbiology, and chemistry are all familiar concepts to us but the traditional Pernians couldn't e more frightened. Especially when AIVAS starts to hint that these new technologies could be used to go into space and put an end to the Threadfall. Once and for all.
I fluctuated from liking this book to being bored by this book. I feel like one hundred pages could have been shaved off, and the book wouldn't have lost too much of its content. There was WAY too much information being thrown out there, and while it was interesting seeing the Pernians' reaction to Science! I also feel that a lot of the dialog was pretty useless when it came to plot development. Also, as a few of the other reviewers pointed out, the Pernians managed to get all of the concepts very quickly, and with little disbelief.
Also, AIVAS talked waaaay too much. You could literally not go more than five pages without seeing him appear. He's like HAL's well-meaning but utterly annoying brother. And what was with that ending? I'm with that character. Machines don't die! Wtf.