The setting: human beings have colonized other planets, and cross vast distances in their warp-drive space ships. It's been done before, you say? Well, what if I tell you that the space ships can divide in two, like molecules?

British author Tony Ballantyne takes the space-opera sub-genre and makes it wholly his own. Divergence is the third book set in a future when self-replicating machines run rampant, chewing up everything in sight to make more copies of themselves, and the humans that remain on earth live under the happy thrall of an Artificial Intelligence called the Watcher. Godlike as the Watcher is, he naturally has to have an adversary, a Satan. Curiously, this Satan, another AI, is named Chris.

This novel brings up questions of free will: is it better to be free to make the usual neurotic mess of things, as humans will, or to be under the control of an AI who labours to make your life run as smoothly as possible? What if you are permitted to choose, but software ensures that the desired end result comes about regardless? Do your choices mean anything then?

This is a novel of ideas. Read it, and your brain will fold itself into origami. And then it will thank you for it. One caveat: the ending is puzzling and unsatisfying.