The Green Sky Trilogy is a rather interesting series by Zilpha Keatley Snyder. The whole premise is that Raamo, a young kid, is selected to become a new Ol-zhaan (priest) of his people. When he begins the training he finds out that there is this great conspiracy happening. His people live in the trees and are never allowed to leave the canopy. He, through a series of events, does so and finds out the forest floor is not what they’ve been told.
I though these books were interesting. There were definitely some political overtones to me. But, from the strict standpoint of the story – it was good. Maybe the political overtones were just my imagination. I will admit that. The characters are likable and the plot is sufficiently complex to make an interesting story. It is still a young adult’s trilogy and not an adult’s, so don’t go in expecting something more like a Tolkien world.
In the end I would say read it if you have a chance. It is worth it.