Season 3 begins on New Year's Eve in 1922, but gangster Gyp Rosetti isn't in a celebratory mood after hearing Nucky's plans to alter his business model. Meanwhile, in Chicago, Irish mobster Dean O'Banion gets on Al Capone's last nerve, and Van Alden hopes for a career boost. Also in Atlantic City: Richard mentors Tommy Darmody, though Gillian keeps a watchful eye on both of them; Margaret tours a new hospital made possible by Nucky's fortune.