Foundation's Edge by Isaac Asimov
US$1.98
Paperback. Condition: Good. 1982. Del Rey.
It is 498 years since the two Foundations came into existence - half-way through the Interregnum planned by Hari Seldon. The Second Foundation has once more successfully concealed its existence so that the laws of psychohistory can operate to usher in a new Empire ruled by the mental sciences.