Transference

Emilia awoke sprawled on the cold stone floor. Every bit of her was freezing. When had it gotten so cold? She remembered stepping down into this dungeon... in the sweltering desert heat... she wandered into this room that her friends seemed to have missed... and then... nothing.
Emilia tried to regain her bearings. She was bathed in blue light. She look up and saw the torch she had lit still crackling in its sconce, but emanating an unnatural blue light and providing no warmth. She tried to push her body off the floor. The stone beneath her felt like jelly, as if her hands were barely able to press onto it without slipping through. She caught sight of her hands, almost glowing blue in the strange light. The veins on her hand were swollen and discoloured, looking almost black...
Emilia's eyes widened. She moved her hand, and the veins didn't move with it. They were cracks on the stone floor. She could see through her hand! Looking down at the rest of her body, she saw the details of the floor breaking through, as if they were on the other side of the window. Something was seriously wrong. Emilia struggled to her feet, the hard floor feeling unstable under her. She had to find her friends, maybe they would know what to do. Turning towards the room's only exit, she saw a figure standing there in the doorway. It looked almost exactly like... her.
The figure had her hair, her face, her figure, her everything. But she was solid. The light sources around the room bounced off her, shined off her glasses. Emilia just stared in confusion. The figure, meanwhile, smiled.
"You have a nice body," it said, in Emilia's own voice. "Perhaps a bit small, and a bit weak, but perfectly serviceable. It will do nicely."
Emilia could barely make out the words. Though she stood just in front of the figure, it sounded as if it was whispering to her from the other side of a wall. "What are you?" she demanded. "What have you done to me?"
The figure continued smiling as it looked itself over. "These are quite fancy clothes and equipment. You're rich, as well? Excellent." It caught sight of Emilia's gestures at it, and turned to face her. "I can't hear a word you're saying. No sound you make can pass this seal." It gestured to all the intricate carvings on the walls and floor of the room's entranceway. "I should explain. I was like you, once. A treasure hunter, a grave robber. I broke into this dungeon in the hopes of finding riches. Instead, when I stepped into this room, I was trapped. The light, the cold, it was unbearable. The last thing I saw before I was left alone in this purgatory was my own body running out of this room. I understand now what had happened."
Increasingly frantic, Emilia called out to her friends, as loud as she could. If the person in her body could hear her, they made no indication of it.
"There is nothing you could promise me that would have me step foot in that room again," her body said matter-of-factly. "But take heart! The days soon blur together. I have been set free, and one day you will be as well. Perhaps soon! Now, while it is... amusing to see you in my place, I have no desire to ever see this room again. I miss food and drink, I miss sleep, and I miss my home. I cannot wait to see Ordulin again."
Emilia's face contorted from panic to despair. Ordulin had been destroyed 120 years ago. She steeled herself, willing herself to remain focused, and sprinted at her hijacker. Nearing the entranceway, every source of light suddenly shifted from blue to red. Searing pain took hold of every part of her body. She screamed and fell backwards, and the lights became blue once more. The pain in her body subsided, leaving her once more in the freezing cold. The thing in her body stifled a laugh for a moment. Suddenly it stood alert. It glanced towards the entrance of the dungeon, before looking back at Emilia, smiling smugly.
"So, you're 'Emmy', eh?" it began, and then called out. "No, there's nothing down this way! We should head back!" It took one more look at the new apparition. "Best of luck, 'Emmy'," it said, and calmly walked out of sight.
Emilia sat curled up on the floor, still reeling from the pain. The room was too bright, too cold, too small, too bright, too cold, too small...
All she could do was hope someone else would visit soon.