The Left Hand of Darkness by Ursula K. Le Guin

A beautiful Science Fiction touching on great human themes.

Ambassador to the planet Winter Genly Ai navigates factions and culture as he both try to understand himself the world he is on. This is a remarkable book. The aliens are human-like, but also very different, and Le Guin in show how a few changes to an environment may result in alien social concepts. There are two main factors that have steered the society Ai tries to understand: First, the inhabitants of the planet have no sex but for specific times of year - 'kemmer' - when any individual randomly turns either male or female. Any individual can therefore bear children. Second, the planet simply has long cold winters. There are of course many other details and concepts sprung from these woven into the rich story, and the more one thinks about them the clearer it is how much work the author has put into this book, and what a masterpiece it is.