By Isaac Asimov
Thousands of years in the future. Mankind has settled every known habitable planet in the galaxy. The whole galaxy is ruled by the Galactic Empire, on the planet Trantor, which is as close to the galactic center as possible. Hari Seldon sees that the empire is crumbling before them, and that there is no way to prevent this. But, he does see a way to make this transition period between empires shorter, from 30,000 years to only 1,000 years. He knows this through "Psychohistory" ; The science of probabilites of masses of people. As humanity is now numbered in the trillions over all the planets, the paths that humanity take can now be accurately predicted. So Hari Seldon grabs the best known physical scientists in all the worlds and brings them to a planet as far away from any other as possible. The farthest planet from the center in all the galaxy, Terminus. There these scientists are to build the Encyclopedia Galactica, of a culmination of all the known knowledge in the galaxy. But their planet doesn't get left alone for long, and it's up to them to find a way to keep their project going and to expand their power.