Anderson Scott Anderson 
Circle and the Landmark [EPUB ebook] 

An enclosed circular world in the far distant past had been created for the benefit of a young human race. Circling a uninhabited blue-water planet, those on the manufactured world known as Belaire have a life that could only be described as paradise. Those working to change or expand the progress of Belaire make an attempt to call out to the galaxy to anyone who will answer. The unexpected response will place millions of people in grave danger. As expected, some will step up and meet the challenge, while others will fall at the first sign of trouble. In the end new, allies will be forged, but not without sacrifice.