Will humans ever split into separate species? If so, what will be the cause and how will it happen? Octavia Butler addresses these questions in this fine novel. I was about to say that it was one of her best, but then her books usually divide themselves for me into the excellent and the truly outstanding, and there are more of the latter than the former. The quality of her fiction is better than any scifi writer I have ever read.
Her characters, even inhuman mutants, are entirely believable as they embark on the strangest of journeys into the unknown. And it is so well imagined as to be completely believable. Usually, I have to fight to stop thinking, "OK this is someone just thinking this up." Butler puts you into these fantastic worlds. So the heroine of this novel enters into a struggle with Doro, the vampiric mind-entity that has bred humans with purpose for thousands of years. As the culmination of his efforts - a theme in sci fi from Frankenstein but since then never so freshly done as Butler has - she will either grow beyond him or be destroyed.
Butler understands power so well, not so much from the point of view of those accustomed to wielding it as from those who must submit or die trying to escape it. Outstanding. It is a pity that the British don't know about this American author.