What may have seemed at first a slow beginning turned out to be ominous to the climactic ending. The uncanny warm goodbye of Serena to her Martha, Serena's suggestion to go without a driver, her farewell look at the past road and the hopeful smile at the future road ahead, the final intimacy act, the guilty and worried look on Serena's face when Tuello asked them to follow him; all indications that Serena anticipated - and probably planned - the fate of her husband. The cinematography was amazing and also served the purpose of foreshadowing the eventful ending. The crossed bridge raised a red flag for me with its clinched fists or teeth-like structure foretelling the Waterfords' faith. Certainly there is that welcome satisfaction with the retribution of Commander Winslow and the shocking cold - efficent handling by the housekeepers on the sounds of Kate Bush's masterpiece, but that has been addressed in other reviews.
In short, this was the perfect episode in all regards. Best direction, cinematography, acting, plot and soundtrack.