This book is interminable. It is the sequel to Robots of Dawn and is set 150 years after Elijah Bailey's death. Keldon Amadiro, a powerful politician on Aurora who was defeated as a result of Bailey's investigation in Robots of Dawn, is trying to take revenge on Bailey by destroying Earth. Only Eliajah's robot pals, Giskard and Daneel, know what is really going on, and they race to Earth to try and thwart Amadiro, while Gladia finds a new role for herself after over 200 years of life.

This is a good end to the robot stories, with explanations along the way of how Earth becomes radioactive (it's not what you think), why there are no robots in the empire or foundation stories, and how the idea of psychohistory got its start. However, that doesn't make this a good book. This book is the crucial link among Asimov's three major series, and as such has many of the elements of the second act of a three act play. The emphasis in this book is on tying up all the disparate elements rather than telling a self-contained story.

The introspective moments that Giskard and Daneel share are boring. There is far too much telling in this book and far too little showing, and the Gladia story is disconnected from the Giskard/Daneel story. In many ways, I think this should have been two books -- one about the politics of settlement, and one about the robots. All in all, this is a book for completists, who want to know more about the robots -- it isn't a book for someone with a passing interest in things Asimovian.

[note: this was a re-read for me]