HBO has released the second trailer for Boardwalk Empire, returning with the Season 3 Premiere Sunday, September 16 at 9 PM ET. Steve Buscemi returns in his Emmy-nominated role of Nucky Thompson, the ruthless gangster who controls Atlantic City during the Depression Era. Take a look at this new video where Nucky guns down a man in the pouring rain, proving he's not just a half-gangster.