Sister Light, Sister Dark - Jane Yolen
When I had the chance to pick up a copy of Sister Light, Sister Dark (currently out of print in the UK, alas) I jumped at the chance and enjoyed it very much. In some ways, it could be easily pigeonholed as the stereotypical YA novel about a young person who discovers they are actually more than initially met the eye, but Yolen's writing and characterisation lifts this book above that.

Our protagonist is Jenna, who has been fostered by the Altites since she was a baby - they are a community of women warriors who have found a way to increase their numbers by means of their 'dark sisters', a shadowy counterpart of the majority of them who can only be seen by moonlight or artificial light. As with many YA fantasy books, there is a prophecy in relation to a child with white hair who will be the Anna, a child who has been orphaned three times and whose coming heralds 'the end of things'. As time goes on, more and more of the people associating with Jenna realise that she may well be the one whose coming was prophecied.

What I really liked about Sister Light, Sister Dark is the way that Yolen structures it, as the story of Jenna is also bracketed by both myth (so you can see how the actual story could be twisted to suit the needs of particular groups) and by academic discussion (often just as far of the mark). And although there's a budding romance between Jenna and a fugitive princeling she and her friend Pynt rescue, it's low-key enough not to annoy. The story continues and concludes in White Jenna, which I hope to get hold of.