The Left Hand of Darkness is a science fiction novel written by Ursula K. Le Guin. It takes place on the planet Gethen, where the inhabitants have no fixed gender. The book follows the story of a human envoy, Genly Ai, as he navigates the complex social and political landscape of Gethen. The Left Hand of Darkness explores themes of gender, identity, and the nature of humanity in a thought-provoking and imaginative way.