S3, E23: Elizabeth heads to Brussels to seek NATO's support against Russia when it threatens to invade Bulgaria, but when France refuses to cooperate, it could threaten the alliance's very existence. Also, Henry's new government role has him dive into the Russia issue and turn to his former operative, Dmitri Petrov (Chris Petrovski) for help, and as Nadine and Mike B's relationship heats up, Elizabeth finds out information about her old friend that makes her question his loyalties. (TV-14 L)