When a Navy reservist returns home to find her husband missing and her living room covered in blood, she turns to the NCIS team to bring him home.
Atlantic City kingpin Nucky Thompson battles for control of the area's bootleg whiskey business.
Van Alden is ordered to keep tabs on Al Capone; Dr Valentin Narcisse clashes with Chalky and Nucky; Agent Knox aligns himself with J. Edgar Hoover; Harrow fails to finish a job; Eddie demands a promotion; Nucky leaves for Florida.
Arnold Rothstein agrees to bankroll Nucky's Tampa investment, but first demands that they get the measure of each other over a game of poker.
Chalky White asks Nucky for permission to take out Valentin Narcisse. In Chicago, the Capone brothers recruit Van Alden.