Writer/editor Silverberg has finally done it: produced a long, absorbing, far-future saga with substantial characters and a plot that adds up. For 700,000 years, ""death-stars"" from space have rained upon the Earth, destroying the ancient civilizations and creating a glacial climate. Now, as the bombardment ends and the land warms, various tribes of humans emerge from their protective ""cocoons"" to reclaim the world. One such tribe--led by stern, wise Koshmar, and stirred by the young, inquisitive Hresh--is determined to find the fabled ancient city of Vengiboneeza where, according to tradition, they will discover the means to rebuild civilization. Finally, after braving many dangers, they reach the city. Hresh, who has the most highly developed psi-powers of all the tribe, uncovers usable ancient machines, and rediscovers the city's ancient history--but to his shock and consternation, he learns that his people are not humans, but evolved monkeys. Still in the future for Hresh's folk: tragedy and a parting of the ways for the tribe; a challenge from a rival tribe, the advanced, knowledgeable, snobbish Beng; and an invasion by the teeming, insectlike hjjk, who have laid their own plans to dominate old Earth. Tingling, fascinating work, richly detailed and satisfying: Silverberg's best full-length outing for many a long year.