This is a sequel to 'Capacity' and has many characters in common. While not (on the face of it) as complex or as fast-paced as its predecesor, it does move steadily towards its tremendously thought-provoking climax. It's almost impossible to describe without giving the game away, but suffice to say that Ballantyne is tackling huge themes here, and doing it with great confidence. And if this book smacks at times of the mystical, well that's one of the things that great sci-fi can handle really well. Read this if you like the work of Cordwainer Smith (it has some themes in common, even though Ballantyne has a distictive voice of his own), or if you are an afficionado of literate, concept-driven science fiction. By the time I'd finished it I was proud to be a flawed human, and I think you will be too. It's only his third novel, as far as I know, but he just gets better and more ambitious. What is amazing is that he can carry it off so well.