But suddenly the Mirror went altogether dark, as dark, as if hole
had opened in the world of sight, and Frodo looked into emptiness.
In the black abyss appeared a single Eye that slowly grew, until it
filled the nearly all the Mirror. So terrible was it that Frodo stood
rooted, unable to cry out or to withdrow his gaze. The Eye was
rimmed with fire, but was itself glazed, yellow as a cat's, watchfull and
intent, and a black slit on it's 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 many things that it sought he himself
was one. But he also knew that it could not see him - not yet, not unless
he willded 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.
`Do not touch the water!' said the Lady Galadriel softly. The vision
faded, and Frodo found that he was looking at the cool stars twinkling in the
silver basin. He stepped back shaking all over, and looked at the Lady.
from The Fellowship of the Ring "The Mirror of Galadriel".