"At last Sam could bear it no longer. "What's all this, Gollum? ' he said in a whisper. "These lights? They're all round us now. Are we trapped? Who are they? '
Gollum looked up. A dark water was before him, and he was crawling on the ground, this way and that, doubtful of the way. "Yes, they are all round us," he whispered. "The tricksy lights. Candles of corpses, yes, yes. Don't you heed them! Don't look! Don't follow them! Where's the master? '
Sam looked back and found that Frodo had lagged again. He could not see him. He went some paces back into the darkness, not daring to move far, or to call in more than a hoarse whisper. Suddenly he stumbled against Frodo, who was standing lost in thought, looking at the pale lights. His hands hung stiff at his sides; water and slime were dripping from them.
"Come, Mr. Frodo! ' said Sam. "Don't look at them! Gollum says we mustn't. Let's keep up with him and get out of this cursed place as quick as we can - if we can! '
"All right," said Frodo, as if returning out of a dream. "I'm coming. Go on! '
Hurrying forward again, Sam tripped, catching his foot in some old root or tussock. He fell and came heavily on his hands, which sank deep into sticky ooze, so that his face was brought close to the surface of the dark mere. There was a faint hiss, a noisome smell went up, the lights flickered and danced and swirled. For a moment the water below him looked like some window, glazed with grimy glass, through which he was peering. Wrenching his hands out of the bog, he sprang back with a cry. "There are dead things, dead faces in the water," he said with horror. "Dead faces! '
Gollum laughed. "The Dead Marshes, yes, yes: that is their names," he cackled. "You should not look in when the candles are lit."
(J.R.R. Tolkien, The Lord of the Ring - The Two Towers, book IV, Chapter 2: The Passage of the Marshes)