This one was great! With all the backing of Robots, Empire and Foundation Asimov throws the galaxy into a three way standoff between the first and second foundations and some third initially unknown player.

The time line does not jump generation to generation, so all characters are explored far better than those of the foundation trilogy, and since there are a number of double agents - sometimes even unknown to themselves - characters have a lot of intreague.

Even as a standalone story outside of the time line, this book stands up to scrutiny. Everything that happens is interesting and in general is a fine penultimate volume - setting up the climax to be huge!