Led by its founding father, the psychohistorian Hari Seldon, and utilizing science and technology, the Foundation survived the greed and barbarism of its neighboring warrior-planets. Now cleverness and courage may not be enough. For the Empire--the mightiest force in the Galaxy--is even more dangerous in its death throes. Even worse, a mysterious entity called the Mule has appeared with powers beyond anything humanly conceivable. Who--or what--is the Mule? And how is humanity to defend itself against this invulnerable avatar of annihilation? Filled with nail-biting suspense, nonstop action, and cutting-edge speculation, Foundation and Empire is the story of humanity's perpetual struggle against the darkness that forever threatens to overwhelm the light--and of how the courage of even a determined few can make all the difference in the universe.