In the months following the release of "The Prestige" (another of Nolan's movies, released in 2006), Nolan made many comments suggesting that he would return to direct the sequel to "Batman Begins". In late July 2006, the sequel was officially confirmed as "The Dark Knight" with Nolan at the helm and Heath Ledger joining the cast as The Joker, Batman's nemesis. Nolan and his brother Jonathan wrote a script, based on a treatment written by himself and David S. Goyer. The movie began production in early 2007. It was released on July 18 2008 in the United States, to overwhelming critical acclaim. It has also made a lot of money, setting the record for the highest-grossing weekend opening in the U.S. with over $158 million.