THE RINGWORLD THRONE

Third in Niven's famous Ringworld series (The Ringworld Engineers, not reviewed), set on a colossal space habitat that forms a complete ring, 600 million miles in circumference, around its sun, and comes complete with cleverly engineered days and nights, seasons, oceans, mountains, and what-all. Earth explorer Louis Wu has been trying to evade the surveillance of the Hindmost, a manipulative alien puppeteer who, despite his advanced technology, is trapped on the Ringworld. Nevertheless, the Hindmost observes everything that occurs, especially—in the first (intriguing but largely irrelevant) section—how a motley band of assorted humanoids somehow pool their talents to wipe out a bothersome nest of Vampires. In the second section, exciting but very hard to follow, the Hindmost notes with interest that a powerful Someone seems obsessed with protecting and maintaining the Ringworld. And soon both Louis and the Hindmost are being controlled by a protector, Bram, a Vampire transformed by a virus and a particular diet into a superbeing. Neither is Bram alone—and the problem is that protectors of different species instinctively fight to protect their own species' genes. Someone, however, must take control of the Ringworld to ensure its survival. . . . Notably schizophrenic and confusing but inventive enough that Ringworld admirers will surely wish to investigate.