The hunt for the secret Second Foundation intensifies on two fronts: the Mule seeks it to neutralize the only power that can stop him, while the First Foundation, having defeated the Mule, now fears the Second Foundation's hidden mental influence over their destiny. The final volume of the original trilogy resolves the trilogy's central conflict through clever misdirection and a revelatory ending. A satisfying and intellectually playful conclusion to Asimov's original grand design.