Over at The Guardian, Sarah Crown discusses why she rates Sauron in The Lord of the Rings as the most frightening and enduring villain of all literature.
I think there could be something to this. I recall vividly just how much Sauron’s unseen — yet uncannily tangible — menace frightened me as a teenager reading The Fellowship of the Ring late into the night, especially whenever I reached the following passage from The Mirror of Galadriel.
But suddenly the Mirror went altogether dark, as dark as if a hole had opened in the world of sight, and Frodo looked into emptiness. In the black abyss there appeared a single Eye that slowly grew. until it filled nearly all the Mirror. So terrible was it that Frodo stood rooted, unable to cry out or to withdraw his gaze. The Eye was rimmed with fire, but was itself glazed, yellow as a cat’s, watchful and intent, and the black slit of its pupil opened on a pit, a window into nothing.
Then the Eye began to rove, searching this way and that; and Frodo knew with certainty and horror that among the many things that it sought he himself was one.