The Erthring Cycle by Wayland Drew Book

This is a combined book of the following books: The Memories of Alcheringia, The Gaian Expedient, The Master of Norriya. It is a post-apocalyptic story of a group of scientists who set up an experiment on a land, trying to keep the people in a less developed state so they never reach the point in civilization where they are able to destroy mankind. This book follows the scientists as well as the people on the mainlands.