Planet of Stones

Lieutenant Connelly is one of six Monitors sent 100,000 years into the past to study the tribes of two recently discovered humanoid species. Each Monitor lives alone in isolated outposts located far apart from one another around Alpha Valley. Connelly's only companion is Box, a small A-I device that he carries about with him in his pocket. Two years into his three year mission, he is unexpectedly recalled to Central, an underground facility in the heart of Alpha Valley and from where he will be returning to Point Zero... home to the year 2058. His journey back to Central includes several unplanned detours having to deal with both the Littles and the Alphas, the two species that he has been unobtrusively observing. Reaching Central at last, Connelly and Box find that their mission wasn't at all what they had thought it was... and that he won't be going home quite yet....