It's possible, of course, that the Silence may have slipped your mind. Yet their role in the Doctor's woes is far from over. So, who, or what, are they? And what do they want? So far, we've been told that they're a religious order founded around the belief that “silence will fall when the question is asked” – something that would explain their motives in preventing the Doctor from reaching the mysterious Fields of Trenzalore. It's also been said that they consider themselves the “Sentinels of History”, so are they trying to kill him for their own selfish means, or for the greater good?