There are several things that I particularly love about S. Andrew Swann's Apotheosis series, and they're at their best in Messiah:
* The science fiction concepts are an integral part of the plots and scheming, rather than mere window-dressing. The manner in which tach drives operate, for instance, is something on which many plot developments hang.
* You won't find just one or two major plot twists here and there. Swann throws them out hard and fast. Every time the good guys take a step, they're knocked back another. Every time it seems Adam has become unstoppable, another ray of hope peeks out.
* Swann has a novel way of depicting a uniquely wide variety of relationships. Now that more of the characters have been fleshed out, it's much easier to appreciate this.
It's rare to find a series that can live up to this kind of dramatic buildup, but Apotheosis manages it. If anything each book was a bit better than the last. This is one series in which the author is not afraid to make sweeping changes, to permanently and vastly alter his universe, and to take on risky topics that are difficult to do justice to. While Prophets started out a little stiffly with some info-dumps and somewhat weak characters, the series has steadily improved throughout, going from quite good to fantastic.
[NOTE: review book provided by publisher]