Better than both the first and second book’s in Asimov’s Foundation Series.

This third instalment begins from the aftermath of the Mule’s annexing of the Foundation and tells the story of his, and his successors drive to find the elusive Second Foundation.

The leaders of Terminus of the First Foundation believe that Hari Seldon devised the Second Foundation to ensure the longevity of the First’s rule of the Galaxy. They may have been mistaken.