I also love how vividly Tolkien portrays evil in The Lord of the Rings. He makes you feel how seductive, how terrifying, how oppressive – how truly evil – it is. For example, I love when Frodo is looking into the Mirror of Galadriel and see Sauron’s eye:
“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 fimmed 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 it sought he himself was one. But he also knew that it could not see him – not yet, not unless he willed it. The Ring that hung upon its chain about his neck grew heavy, heavier than a great stone, and his head was dragged downwards. The Mirror seemed to be growing hot and curls of steam were rising from the water. He was slipping forward” (364).