I give fair warning that the following review may give away plot elements from the previous books so read ahead at your own risk.

The original Foundation trilogy described the first 400 years of the First Foundation. At the end of the last book, the First Foundation rested secure in the belief that they had defeated the Second Foundation and established themselves as the true seeds for the rise of the second galactic Empire. Of course, this is what the Second Foundation wanted them to believe and was part of an intricate plan to convince the First Foundation of their so-called demise.

Foundation's Edge begins about 100 years after these events and at a time where the Foundation is seemingly at the height of their power. However, this notion is challenged by Golan Trevize, a renegade councilman, who believes that the Second Foundation still exists and are the ones in real control.

Despite the fact that the Mayor of Terminus shares these beliefs, she uses Trevize's unpopular rhetoric as a reason to send him into exile and in the company of a obscure historian by the name of Janov Pelorat who is in search of the planet Earth, which by now is lost in antiquity. The Mayor intends for Trevize and Pelorat's mission to serve as a lightning rod to draw out the Second Foundation so that they can be confronted.

It doesn't take long for Trevize to become interested in the idea of a single planet that served as the provenance for humanity. Their search for Earth ultimately leads them to the discovery of a mysterious world known as Gaia.

This mythical world becomes a focal point for a confrontation between the two Foundations and a decision that will decide the fate of humanity in the galaxy.

This novel is rather different from the original series and focuses on the actions of a few key characters. Asimov also gives the reader greater detail of the true workings of the Second Foundation, which was lacking in the previous novels.

I rather enjoyed the character interactions in this book, particularly between Trevize and Pelorat. Pelorat is probably one of my favorite characters from the Foundation universe, right up there with Salvor Hardin, the Mule and Hari Seldon himself.

The story proceeds along three angles which all ultimately come together at the end. A large portion of the story details the adventures of Trevize and Pelorat as they hop from world to world in search of information regarding Earth. On other fronts, we observe the actions of both Foundations as they react and maneuver to exploit Trevize and Pelorat's discoveries.

I rather enjoyed this novel, though I'm not sure how I feel about Asimov's casting aside of the Seldon Plan. The book culminates with the emergence of the 'Gaia theory' which basically supercedes the Seldon Plan. I won't give away the details of this theory as its final revelation is a large part of the book's appeal.

Whether or not you like the book will probably depend largely on how you feel about Gaia at the conclusion. I found the idea to be rather fascinating, though some of its implications trouble me. There is a great deal of potential here for some interesting stories and it is too bad that we won't be able to see what Asimov could have come up with.

In conclusion, I would highly recommend this book to fans of the original series. I suppose you could read this book without having read the previous Foundation novels, but why would you want to? If you love Asimov's Foundation universe, then this is definitely a book you'll want to check out!