No matter how powerful and moving a book is it doesn't usually make me cry. This nearly got me several times and then the last few pages finished me off and I couldn't stop myself. It's intelligent and moving and utterly suffused with beauty sadness, and heartbreak. The characters and events are completely compelling and develop effortlessly. Either ignore that it's considered sci-fi, or open your mind to how elegant and well written sci-fi can be, and just read it.