In the year 10,191 A.G. (After Guild) (23,190 AD), the known universe, a sprawling feudal galactic empire, is ruled by the Padishah Emperor Shaddam Corrino IV. In this time the most precious substance in the universe is the spice melange, which extends life, expands consciousness and is vital to space travel. The powerful Spacing Guild and its Navigators use the orange spice gas to achieve a sense called prescience by which they safely guide the interstellar ships to any part of the universe using the quantum mechanics of Holtzman generators, an extremely complicated machine which "folds space" (in effect, the ship is moved instantaneously across vast distances).