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?

***Note: This work incorporates “The Mule,” originally published in 1945 in Astounding Science Fiction. “The Mule” was awarded the 1946 Retro Hugo Award for Best Novel. As the story was first published in magazine form and has no original ISBN-bearing edition, the award is associated here with its later appearance in Foundation and Empire.