Interesting book. The premise is that childless individuals are considered dispensable and once they reach a certain age they go into the Reserve Unit where they participate in various experiments and donate various organs until their final donation of vital organs. The thing about this book is I can totally see this happening in the future. The way our society is headed, this is a very plausible future. As someone who doesn't have children, the book struck a bit of a chord with me in how society views those who don't procreate. Contributing to society by having children that will be useful to society is what makes you needed. If you don't, then you are considered dispensable.