Mount your dragons and hold the door -- a "Game of Thrones" play is in the works. Author George R. R. Martin, along with a team of Broadway veterans, will adapt a brand new story from the "A Song of Ice and Fire" universe for the stage. Productions are set to debut on Broadway, London's West End and in Australia by 2023. Author of "Fire Cannot Kill a Dragon" and the Hollywood Reporter's Writer at Large James Hibberd dropped the news on Twitter, calling it "a dramatic stage spectacular" and "entirely unexpected." What's in store for Westeros?