Atlantic City, 1921. Though his fortunes have soared in the wake of Prohibition, Nucky Thompson (Steve Buscemi) is paying a steep price for wielding ultimate power in "the world's playground." Following the 1920 election, Nucky finds himself the target of an investigation for voter fraud and faces not only jail, but insurrection by some of those he considered his closest allies, including mobsters like Arnold Rothstein, Lucky Luciano, Meyer Lansky and Al Capone, who wait in the wings, looking for the chance to grab a bigger piece of Nucky's pie.