Let me start by saying that I have read all of Asimov's Robot series and enjoyed them tremendously. To me, this book represents a major achievement in the understanding of robots in Asimov's Universe. I completely enjoyed this book from cover to cover, reading it in one night. But the most important part (I think), was how Caliban developed. Never before have we had a look into a robots mind like this, regardless of the Three Laws. The way Allen described the development of the robot was amazing. I hope to see more of his development in Inferno, which I will definitely purchase. In addition, I thank Mr. Allen for leaving Asimov's Universe intact, not changing any of his fundamentals (Except for the Three Laws obviously), and for helping to fill a blank in Asimov's future history between the Spacer and Settler era, and Trantor's rise.