Preview of World of Ptavvs Summary:

World of Ptavv s deals with the contact between men of several centuries hence and Kzanol, an alien thrint who had buried himself in a stasis field millions of years ago and is only now excavated. The thrints possessed telepathic powers that enabled them to control other minds and with the aid of amplification helmets they established an interstellar Slaver Empire. Kzanol plans to do the same thing on Earth, which he regards as a world of ptavvs, the thrint word for slaves. Niven's chief social concern is how man survives and flourishes in a hostile universe. By the time of this novel, Earth is exploring other worlds both inside and outside of the solar system. Kzanol is but one of the many dangers that they will find and have to handle.

Niven, like many science fiction writers and readers, believes that men will...