There is a long and painful distance between the lived Mexica world and the small clutter of carved stones and painted paper, the remembered images and words, from which we seek to make that world again. Historians of remote places and peoples are the romantics of the human sciences, Ahabs pursuing our great white whale, dimly aware that the whole business is, if coolly considered, rather less than reasonable. We will never catch him, and don't much want to: it is our own limitations of thought, of understandings, of imagination we test as we quarter those strange waters. And then we think we see a darkening in the deeper water, a sudden surge, the roll of a fluke – and then the heart-lifting glimpse of the great white shape, its whiteness throwing back its own particular light, there, on the glimmering horizon.