Disclaimer: Lord of the Rings don't belong to me. The other ideas do.
Into the Mists
"The realm of fairy-story is wide and deep and high and filled with many things: all manner of beasts and birds are found there; shoreless seas and stars uncounted; beauty that is an enchantment, and an ever-present peril; both joy and sorrow sharp as swords. In that realm a man may, perhaps, count himself fortunate to have wandered, but its very richness and strangeness tie the tongue of the traveller who would report them. And while he is there it is dangerous for him to ask too many questions, lest the gate should be shut and the keys be lost." – J.R.R. Tolkien "On Fairy-Stories,"
The woods had been full of mists lately, wrapping the trees in an almost transparent silvery cloth. It turned the elves that moved through the trees into ghosts, instead of shadows. The trees seemed to be tense, barely rustling or speaking. The air felt thick and sticky, making Legolas shiver unexpectedly as he rode out of his father's hall. He looked around, trying to peer into the shadows, shadows that were covered up by the mists, trying to see what had made him shiver so. Yet nothing seemed out of place. All that there did seem to be was a sense of expectation; a sense of something waiting to happen. Shaking his head to try and free himself of that sensation, he urged his horse forward into the woods.
He wasn't planning to stray from his father's protected borders, so he took no guard with him. It was just a ride to stretch his horse's legs and clear his mind of thoughts that seemed to be clouding. For some reason that he couldn't fathom, he seemed to be having dreams of a woman, a green woman to be exact, with a wide smile and laughter in her eyes. And yet there always seemed to be something wrong with the way she smiled and the way she laughed, as if there was a joke that he was the butt of, the victim of a great prank. She never spoke though. Just looked at him and laughed. It caused an itching down his back just to think of it.
Legolas rode into the woods deeper into the woods, eyes slightly closed, trying to get a sense for what the tenseness was, as well as trying to get his mind off that woman. Black squirrels, for a ways followed him, they didn't seem to be bothered by what the trees were, but they were never the most intelligent of creatures. As he maneuvered into a small clearing, really just a break in the trees, he heard a rustling noise.
Breaking free of his trance he opened his eyes and his other senses trying to pin point where the noise was coming from. From his right a stag bounded out of the woods. It paused in the sunlight, gold glinting off of its antlers and hooves, its hide pure white. Its eyes were wild, as if it were being hunted, and it was breathing heavily.
"That's not from around here," Legolas murmured. He started to slide off his horse when the stag gave a snort of fright and wheeled around, thundering back the way it came.
Then, before he could react, he heard more hoof beats and from the same direction as the stag. A man on a black horse broke into the clearing. He wore no clothes that Legolas recognized as being from around the Dale or of the Rangers, though it was to the Rangers his dress was most like. He carried a bow in his hands, as if her were hunting, perhaps the stag. He had a frightened and startled look on his face as he turned the horse around in the clearing.
Legolas took the opportunity to ride forward, for while a stag was strange, a stranger could be dangerous or even in danger. As soon as the stranger caught sight of him, however, his eyes went wide and like the stage before him, he bolted, the horse giving a whinny of surprise.
Without really thinking about it, Legolas spurred his horse forward into a chase. The other's horse didn't seem to be as agile in the thick forests of Mirkwood, so Legolas had an advantage there. He was able to keep the other rider in sight. As they rode, the mists grew thicker and thicker until all that kept Legolas on the trail was the sounds of the other horse's hooves on the ground. He slowed his horse down some, not wanting to risk it breaking its legs in the unseen forest, but still kept up the chase.
After they had been riding for about twenty minutes, the mist broke and faded away.
What Legolas saw caused him to halt his horse rapidly. From the darkness of the forests of Mirkwood he had come upon a large plain covered in patches of snow. He could see out in the distance scrubs of trees clung together like frightened skeletons, their bark black and dark. The air was crisp and felt different than that of the forest. And the sky seemed to be caught in twilight, streaked with pinks, oranges and reds. Dancing a head of him, the black horse tossed its head, steam rising from its nostrils. The rider looked back at him, with the same expression as before, fear and surprise. Turning around Legolas saw nothing but snowy plains as well. The forests and mists had vanished.
He appeared to be trapped here. Where ever 'here' was, and it certainly didn't feel like home.