I said it's a vampire book - it's more that the species that the protagonist belongs to (the Ina) are the source of our vampire mythology but the myths and folklore haven't really got it right. The story opens with this particular Ina coming to after what has clearly been a horrific experience - she's badly hurt, and amnesiac. The entire thing is told from her perspective, so we learn about the Ina and how they interact with and live in (but not of) our human society as she does. Fairly early in the book we find out that while she looks about 10 or 11 years old she is in fact 53 but still a child as the longer lived Ina also take longer to grow to maturity (as an aside, Butler was 58 when she died, so given the lead time between writing a book & publishing it I guess this was her own age while she wrote it, or near enough). Some things come back to Shori as she heals, but these things are things like language, reading & writing ability, her sense of ethics - never do the events that lead to her injury come clear, and neither does she remember anything about her life before that. This filled two roles in the narrative - not only did it give us our way into the story, but also it became important to the plot.
The plot itself is in some ways small - it's the story of Shori finding out who she was and what happened to her (and her family), and then doing something about it. The human world isn't really involved, it's all about the Ina and their society and their interactions as they affect Shori. But in other ways it's broader - it's about the ways that people react to change, and to those who are different, and the ugliness that can result from that. The racist overtones are made explicit, and I felt that this was a story using racism to demonstrate how this is one specific ugliness out of a whole group of ugly behaviours and ideas. And also something I'm struggling to articulate clearly about the pettiness of worrying about something like skin colour - from the outside (the Ina side) it should be irrelevant, and having Ina who are even partly concerned about colour it is really clear how pointless that is really. The line is clearly drawn from "but why should she give a damn?" to "why would anyone anyway, really, except for cultural reasons?".
Skin colour comes into it because Shori is dark skinned - one thing the vampire lore gets right is that the Ina aren't able to go out in the sun, they suffer extreme sunburn. Shori herself, we learn early in the story, is the result of Ina genetic engineering, combining (somehow) some human DNA to darken her skin and also to allow her to wake during the day (Ina are generally obligatarily nocturnal). This is a clear and obvious advantage, but it also marks her out as new and different.
Other ways the lore is right is that the Ina live off blood, blood from humans. And they enthrall the humans they feed from using their bite, creating a symbiotic relationship (where the balance of power and benefits is very strongly skewed towards the Ina). And Butler does a fantastic job of presenting this all from the point of view of an Ina, which means presenting it as good and right to the character and yet still keeping the character of Shori sympathetic. I love books that do this - keep you in the point of view of and cheering on a character who is actually doing things that scream "wrong wrong WRONG" at you. There's quite a bit about the benefits the humans symbiotes get - longer life, better health, a life of luxury and unconditional love from their Ina. About how they can keep up family ties, how they're free to marry. And about how it's a choice (normally). But how much of a choice is it really? It's clear that the thrall starts earlier than the Ina say - if you get bitten by an Ina you have to obey his or her commands, if you choose not to be a symbiote then they'll command you to forget this whole thing (which is disturbing in itself). But by the time you're given the choice even tho you might not count as fully "bound" you're already craving them, so is it a choice like the Ina say/believe or just a way of weeding out potentially troublesome cattle who still retain some vestiges of their free will? And as I say I think Butler does a fantastic job writing this - you see it all from Shori's perspective, about how lovely and happy and wonderful this is, and aren't these people lucky. But as the reader you also see the way the humans behave and read between the lines of the things they say and do - and it's clear that slavery is still slavery even if you love your master, and even if some people do actively choose the life.
And then that ties us back round to the racism/other ugly behaviours thread of the story - Shori is a sympathetic character, who tries to behave ethically, even if her behaviour and attitudes are making my hindbrain squeak "wrong wrong WRONG" because I'm on the victim side of her "ethical" behaviour. Just because you think you're doing the right thing and trying at all times to be a good person, doesn't mean you're seeing past your cultural blinkers and actually doing the right thing. And just because someone is doing something repugnant doesn't mean they are an evil person. The world is more nuanced than that, and full of shades of grey. My thoughts on this keep descending into clichés round about now - hate the sin & not the sinner, don't judge someone until you've walked a mile in their shoes, there's something good in everyone, etc etc.
The book also makes me think about nature vs. nurture. Shori's lost all memory of the first 53 years of her life, yet she retains (according to other characters) things that made her Shori - someone refers to her as still having "my Shori's temper", someone else mentions that she's always been "an ethical little thing". Yet she has no explicit memory of any formative experiences - some things clearly just are who she is.
It's also a good story. I didn't think of any of this while I was actually reading it. I just read and wanted to find out what had happened to Shori, what she was going to do about it. It's afterwards, thinking about it to write about it or just having bits pop back into my mind, that I've thought about the other things it was saying beneath the surface. Definitely recommend the book :)