Interesting science fiction ideas but this is written with several story threads that converge at the end. Unfortunately, although some of the threads are worth four stars, others are worth only one. I'm guessing that this is because there are two authors and one is much better than the other.
Although I did finish reading it several years ago, I gave up on this attempt at re-reading because the bad writing didn't outweigh the urge to find out what happened, since I still remembered the rough idea.