It was written after many years of fans asking for more books in the then Foundation trilogy[?]; at time of publication in 1982 it was thus the fourth volume.
Asimov later wrote prequels; in the order of the story it is the sixth novel in the The Foundation Series.
The Mayor of Terminus fears that the mysterious Second Foundation, which is thought to be extinct, will bid for power once the new Galactic Empire is established. Councilman Golan Trevize and Janov Pelorat, Professor of Ancient History at the University of Terminus are sent on a mission to discover its location .
wikipedia.org dumped 2003-03-17 with terodump