City at the End of TimeCity at the End of Time by Greg Bear.In his triumphant return to large-scale SF, Nebula and Hugo–winner Bear (Quantico) links three young drifters in present-day Seattle with an unimaginably distant future. When the drifters answer an odd newspaper advertisement, they soon find themselves caught up in a war between mysterious and powerful forces. Two not-quite-humans, creations of a million-year experiment, have discovered that their ancient fortress/city, perhaps the last refuge of intelligence in a dying universe, is about to fall before the onslaught of chaos.