The Left Hand of Darkness is a science fiction novel written by Ursula K. Le Guin. It is set on the planet of Gethen, where the inhabitants are androgynous and can change their gender at will. The story follows a human envoy named Genly Ai as he navigates the complex politics and cultural differences of Gethen. The book explores themes of gender, sexuality, and the nature of humanity. The Left Hand of Darkness is a groundbreaking work that challenges traditional notions of gender and has had a profound influence on the science fiction genre.