The fourth season of HBO's period drama 'Boardwalk Empire' has been on a casting roll of late, just yesterday announce 'Office Space' and 'Band of Brothers' star Ron Livingston for a regular role, and prior to that 'The Wire' vet Domenick Lombardozzi, and now the series has picked up another major player for the season. Sources say that 'The Hurt Locker' co-star and 'True Blood' player Brian Geraghty is headed to Atlantic City for 'Boardwalk Empire' season 4, but who will he play? Is Geraghty the next big menace to Nucky Thompson?

HBO has yet to set an official premiere date for 'Boardwalk Empire' season 4, most likely placing it among its usual fall schedule, but it seems Nucky Thompson has picked up yet another enemy. Deadline reports that 'The Hurt Locker's Brian Geraghty has joined the fourth season of the Prohibition drama in a recurring role, one which could prove much more than it seems.

Geraghty will play the recurring role of Prohibition agent Loren Knox, newly assigned to Atlantic City and carrying a few ulterior motives of his own. Elsewhere, ‘Boardwalk Empire’ season 4 has recruited Ron Livingston for a new regular role, HBO vet Domenick Lombardozzi as Chicago mobster Ralph Capone, elder brother to Al Capone (Stephen Graham). Recent casting reports suggested that historical figure J. Edgar Hoover might have a recurring presence in the season, but thus far no casting has been announced.

Series creator and show-runner Terence Winter told reporters that ‘Boardwalk Empire’ season 4 would see a bit of a time jump into 1924, often seen as the year gangsters like Lucky Luciano and Al Capone truly came into their own. Winter also previously confirmed of ‘Boardwalk Empire’ season 4 that Gretchen Mol and Kelly MacDonald would indeed return, despite their ambiguous presences at the end of season 3, while Michael Shannon (Nelson Van Alden) would have a stronger presence as a member of Al Capone’s crew.

What say you? Are you looking forward to ‘Boardwalk Empire’ season 4′s HBO debut? What other stars beside Brian Geraghty would you like to see in Nucky Thompson’s world?

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