An extremely interesting novel by Scott, probably my favorite of all her work I've read so far. It seems to have been inspired by Anne Fausto-Sterling's 1993 essay, "The Five Sexes: Why Male and Female Are Not Enough" (http://frank.mtsu.edu/~phollowa/5sexes.html). Humanity has achieved FTL travel, and colonized widely. However, the drug that allows people to survive interplanetary travel has also had the side effect of increasing mutations, causing around 25% of children to be born intersex. Throughout most of the colonized worlds, this fact has been gradually absorbed by society, and five sexes are considered standard, and the corollary gender roles and social expectations to go with each gender have grown up around them as well. However, on one world, long out of touch with its neighbors, society clings to a two-gendered model - everyone, regardless of their physical attributes, must be seen as either male or female. When contact is made again, and trade and business relations grow, the people from other worlds and other societies are increasingly seen as a threat. The book concentrates on one person in particular - Warreven, a 'herm' who has been living as a man, but who would like the freedom to be seen as an individual, without having to fit into a gender role that does not precisely suit. It's a socially complex, idea-filled book, with strong characters. The furor that some of these characters work themselves up into over socially constructed gender roles - up to and including extreme violence - seems absurd - and sometimes unbelievable - until one realizes that our own society is just as bad if not worse, over some of the very same exact issues. Highly recommended.