Contemporary, Science Fiction & Fantasy 

**Best Novel 1970 Nebula Award **Best Novel 1971 Hugo Award The artifact is a vast circular ribbon of matter, some 180 million miles across, with a sun at its center. Pierson's puppeteers--strange, three-legged, two-headed aliens--discovered this ''Ringworld'' in a hitherto unexplored part of the galaxy. Curious about the immense structure, but frightened by the prospect of meeting the builders, they set about assembling a team to explore it: -Louis Wu, human -- old and bored with having lived too fully for too many years, seeking an adventure, and all too capable of handling it. -Nessus, puppeteer -- a trembling coward from a species with an inbuilt survival pattern of nonviolence. This particular puppeteer, however, is insane. -Speaker-to-Animals, kzin -- large, orange-furred, and carnivorous. The kzin are one of the most savage life-forms known. The party's expedition, however, goes disastrously wrong when their ship crash-lands and its motley crew faces a daunting trek across thousands of miles of Ringworld territory. - from Amzon