By Isaac Asimov
Now, 498 years after its founding, the Foundation seemed to be following the Seldon Plan perfectly. Too perfectly. Now an impossible planet -- with impossible powers -- threatens to upset the Seldon Plan for good unless two men, sworn enemies, can work together to save it!
At last, the costly and bitter war between the two Foundations had come to an end. The scientists of the First Foundation had proved victorious; and now they return to Hari Seldon's long-established plan to build a new Empire that the Second Foundation is not destroyed after all-and that its still-defiant survivors are preparing their revenge. Now the two exiled citizens of the Foundation-a renegade Councilman and the doddering historian-set out in search of the mythical planet Earth. . .and proof that the Second Foundation still exists. Meanwhile someone-or something-outside of both Foundations sees to be orchestrating events to suit its own ominous purpose. Soon representatives of both the First and Second Foundations will find themselves racing toward a mysterious world called Gaia and a final shocking destiny at the very end of the universe!
Del Rey/Ballantine Books. November 1983.