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HBO's Boardwalk Empire is gearing up for its exciting and unpredictable third season debut, and what better way to prepare than to catch up on The Complete Second Season, out next Tuesday! Watch an exclusive clip from one of the disc's behind-the-scenes featurettes in which Kelly Macdonald discusses her character's complicated desires.

First Look: 'Boardwalk Empire' Season 3 Pix

"There's been a lot of sexual tension, really, in the air with Owen (played by Charlie Cox) and that's why she can't stand being around him," says Kelly of her character, Margaret Schroeder. "It's too dangerous. She knows her flaws." 

The winner of eight 2011 Emmy Awards and the 2011 Golden Globe for Best Drama Series, season two of Boardwalk Empire finds Nucky (Steve Buscemi) successfully rigging an election and getting a crony elected mayor of Atlantic City. But the celebration is short-lived when he is arrested for election fraud and members of his own inner circle conspire against him, leading to some deadly consequences.

Spoilers: The Shocking Boardwalk Empire Finale

Featuring extras like a character dossier, a "Living in 1921" interactive guide and cast/crew interviews, Boardwalk Empire: The Complete Second Season will be released August 28 on Blu-ray with an HBO Select box set that contains the Blu-ray, DVD and Digital Download of the show.