As the Empire is dying and the Foundation is gaining more power, due to their advancement of understanding in science and Engineering, the two factions struggle over power and fight against each other. A new ruler in the Empire, seems to win that struggle in his favor, pushing the Foundation to the brink of extinction.
The whole Foundation Series is simply awesome. 7 books in total, they are all worth it. And all the rest of Asimov is worth it too.
Foundation Novels in Order:
- Foundation and Empire (this book)
- Second Foundation
- Foundation's Edge
- Foundation and Earth