When bookstore employee and indie author Hugh Howey published his short story ?Wool? as a 99-cent e-book on Amazon in July of 2011, he wasn?t banking on the story transforming his career. He didn?t even post a link to the story on his own website. But ?Wool,? about a post-apocalyptic future in which society has been forced to live underground in a vast silo, quickly became the most popular thing he had ever written. By the end of October, the story had made it on the Kindle sci-fi best-seller list.