"Louis Wu, accompanied by a young woman with genes for luck, and a captured kzin - a warlike species resembling 8-foot-tall cats -- are taken on a space ship run by a brilliant 2-headed alien called Nessus. Their destination is the Ringworld, an artificially constructed ring with high walls that hold 3 million times the area of Earth. Its origins are shrouded in mystery."--Amazon.com.

In 3016, the 2nd Empire of Man spans hundreds of star systems, thanks to faster-than-light Alderson Drive. Intelligent beings are finally found from the Mote, an isolated star in a thick dust cloud. The bottled-up ancient civilization, at least one million years old, are welcoming, kind, yet evasive, with a dark problem they have not solved in over a million years.