Based -- very loosely -- on the fairy tale 'Snow White and Rose Red'. There are some vague, incest-y femmeslash-y implications, so if even a hint of that bugs you, perhaps you should leave.
In a kingdom far away there live two young princesses, daughters of a great king. The king was fair and just, not the wisest of rulers, but well-loved. His first daughter was called Rose Red, for her mother, a beautiful princess, thought her daughter's hair to be the exact shade of red of the rose of the court. The other was called Snow White, for her mother, a great magician, thought the baby's skin to be like the snow that fell on the mountains of the kingdom. Their father called them April and Senna – April meaning 'bloom', and Senna meaning 'calm water,' but they rarely used their true names, preferring the ones their mothers gave them. There was a great rivalry between the two mothers for the love of the king, each often trying to outdo the other, but between the girls themselves such enmity did not exist. On the very day they met as young children of barely two years, Rose Red held Snow White's hand and Snow White carefully toddled after her. This was always to be the way of things; Rose Red taking action and Snow White following carefully behind.
Perhaps this was because the two princesses were so different. Rose Red had fiery red hair and emerald eyes, a rare coloring, and bands of freckles across her nose and shoulders. She was loud and boisterous, as active as a boy. She was talkative without being gossipy or annoying; she would walk up to strangers and talk to them. Most became utterly charmed, and so Rose Red made a great many friends. She entertained them by dancing and singing, reciting poetry and telling stories. She would be a queen one night, locked away in a tower by an evil witch. Other nights she was the witch. In another she was a beggar girl fallen in love with a prince, and in yet another she was a tree who cried for young lovers who died entwined in her branches. There was no one as amusing as Rose Red in the whole kingdom, her friends exclaimed. Surely no one tell such stories so beautifully. Surely no one was so talented as to play both lover and mother and sister and friend as the roles required. Surely no one was half so clever.
Snow White shared her half-sister's fair skin, but there the similarities ended. While Rose Red's glowed with good health, Snow White's was luminous with the delicacy and enchantment that ran in her veins. Her mother was said to have descended from Elvin stock, explaining Snow White's silvery eyes and incandescent hair. Too, Snow White did not act as her sister acted. She rarely talked or sang, but when she did – oh, Rose Red would shiver. For when Snow White spoke, her words were soft and clever. Her voice was sibilant, the soft whisper of a snake or heated iron dipped in cold water. Mesmerizing and not easily forgotten even once the hiss had faded from your ears. On All Hallows the villagers would come to the castle to hear Snow White's stories, for that was the only time she would tell them. Her stories were dark and beautiful, full of twists and turns and monsters with human faces. They are nothing like Rose Red's stories, the villagers said. Nothing at all alike, and certainly nowhere near as pretty. Still, the images from her stories would haunt their dreams, and many a man would call himself foolish for a looking a time too many over his shoulder.
When Snow White and Rose Red were both ten years old, Snow White's mother found she could no longer bear the half-love she had so long been satisfied with. She returned to the land of her birth, leaving Rose Red's mother, the princess, with a hollow victory. Although Rose Red's mother had at last won a secure place in her love's affections, it was only by default. She wished for something she could never truly have; it was common knowledge that on late winter nights the king would look out his window and think of the dazzling witch who had once been his.
Rose Red was elated when she heard the news. "Now you will live with me!" she sang to Snow White, pleased when Snow White answered, "I suppose I shall," because Snow White so rarely said anything, and never wasted words on something so trivial as a simple response.
Snow White soon had a room of her own beside Rose Red's, and the two would often spend the whole day playing together in the village. The village children did not like Snow White, but Rose Red refused to play without her. It did not matter much to Snow White either way; she disliked their games, instead preferring to make the children crowns or necklaces of meadow flowers while watching them play.
More years passed. The two princesses grew taller and more beautiful in her way. Rose Red's hair grew longer; her mind, sharper; her body, lusher. Her voice became like an angel's. Snow White's skin became velvety, her hair like silk. Her eyes glowed. When standing next to each other, the two princesses would stop men and women in their paths, oft struck mute by the sight. They were so beautiful as to be otherworldly.
Nevertheless it was obvious to all who came to court that that Rose Red was the preferred daughter. Some said it was because Snow White reminded the King too much of her mother, others that she was too cold in her manner to him. Still others insisted that Rose Red was everyone's favorite; as beautiful as she was, Snow White never really had a chance next to her sister. The two princesses didn't care. Rose Red chattered carelessly of ruling with Snow White at her side, aware that it would be many years until she was crowned Queen. Snow White, for her part, neither supported nor discouraged Rose Red's wild plans. As always, she stood silently, watching and listening.
As the princesses came of an age to marry, there were many balls at court. Rose Red hosted them all. She was a beautiful dancer, wild and passionate, caring for nothing but the music and the movement of her feet while the song lasted. All the boys wished to dance with her. Except sometimes, that is, when Snow White would get that strange look in her eyes, and then the boys would forget all about Rose Red. This would make Rose Red sad, but only for a little while. After all, Snow White was her other half, her dearest playmate. Surely Rose Red would not begrudge Snow White this?
One morning when Rose Red awoke, she came to find that Snow White was not in her bed. Confused and troubled, Rose Red searched the castle from top to bottom, and did not find her. She searched the grounds and village, plot by plot, and did not find her. She raced through the forest, peering around every tree, and still she did not find her. Only when she ran down to the wharf and out upon the dock did she see Snow White sitting on the edge, like a will o'whisp in the morning light.
"Snow White, what troubles you?"
"Something is coming," Snow White murmured. "When it comes, will you save me?"
Rose Red immediately fell to her knees beside Snow White, throwing her arms around the slighter girl. "Of course," she cried. "Of course I will save you."
"Of course," Snow White echoed. "Of course you will." She returned Red Rose's embrace, burying her hands in Rose Red's hair, like two doves roosting in an autumn tree. Her eyes bored into Rose Red's, and for a moment Rose Red thinks she knows, perhaps, why those other boys paid so much attention to Snow White.
Rose Red and Snow White returned to the castle hand in hand, Rose Red singing as they went along. That night, unable to quell her fear, Rose Red slipped into Snow White's room.
"I had the most terrible dream," she confessed. "Of wolves and dragons and darkness."
Snow White pulled the covers back so Rose Red could slip in beside her. "It was not just a dream. All dreams are real, Rose Red. Just in different places."
Rose Red shivered, and wrapped her arms tighter around Snow White.
The next morning, viewing themselves in the looking glass, Rose Red could not help but notice that that Snow White's lips had turned a dark red, and that her own eyes were glowing.
"I took some of you," she said, surprised. "And you took some of me."
Snow White smiled, took Rose Red's hand, and pulled her towards the docks.
Rose Red and Snow White were to have many adventures with a prince and a jester and a wizard, but those are other tales. This one is Rose Red and Snow White's alone.