"Once, in a cheap science fiction novel, Fat had come across a perfect description of the Black Iron Prison, but set in the far future. So if you superimposed the past (ancient Rome) over the present (California in the twentieth century) and superimposed the far future world of The Android Cried Me a River over that, you got the Empire, as the supra- or trans-temporal constant. Everyone who had ever lived was literally surrounded by the iron walls of the prison; they were all inside it and none of them knew it." -- Philip K. Dick