The Ringworld Engineers (Ringworld #2)

The sequel to "Ringworld". Louis Wu, Speaker-to-Animals, and the Hindmost return to Ringworld. Their aim is to prevent cataclysm. In the process, they find themselves learning Ringworld's incredible secrets.

The Hindmost, recently deposed leader of the Puppeteers, abducts the human Louis Wu (who has become a wirehead) and the Kzin Chmeee (previously known as "Speaker-to-Animals"). Both had been part of the original Ringworld expedition. The Hindmost hopes to acquire Ringworld technology, specifically matter transmutation, to help him regain his position.

Once they reach the Ringworld, Louis and Chmeee are sent out to explore, while the Hindmost remains safely behind on their starship. Louis and Chmeee secretly plot to try to overthrow the Hindmost so they can go home. In their travels, they meet a number of the hominid species that have evolved on the Ringworld.

"This rousing sequel to the classic Ringworld continues the adventures of Louis Wu and Speaker-to-Animals on that fantastic planet."--School Library Journal