Finale of the Great Schools of Dune trilogy.

Navigators, mutated by spice into beings far superior to normal humans, have made space travel possible: their prescient awareness allows them to foresee safe paths through the universe as starships "fold" space. Only one man knows the secret of creating Navigators, and he intends to use them to build a commercial empire that spans the galaxy. However, Josef Venport is embattled by antitechnology fanatics led by charismatic and dangerous Manford Torondo. And between them stands the uncertain new emperor, Roderick Carrino, who was forced to take the throne after his brother was assassinated. The Navigators are the key to charting a glorious future for humanity -- or the end of civilization. --,adapted from book jacket.