Prologue: Silhouettes and Daydreams.
Celestia sipped her tea as she looked out across her kingdom. She smiled as she watched her subjects go about their day. She sighed as she dreamed of the times she was normal like them.
Her mind drifted back to when her and her sister Luna were travelling through equestria, feeling alone and alienated, the two young alicorns had only each other. They had heard tales of a strange being tormenting the land of ponies, and were directed to a forest near the middle of the land.
Luna sighed as she pulled another branch out of her mane. "Tia, what in the world could possibly be in this forest that is so important?"
"The Mystic was rather cryptic, dear sister, all he said was that there was more power then we could ever hope to understand." Celestia answered, pulling some low hanging branches away so she could continue forward.
"Maybe he confused 'Forest' for 'Power' because that's all that is out here." Luna grumbled.
"Or maybe he was just trying to be rid of us, like everypony else. . ." Celestia sighed, pausing to let Luna catch up. As Luna drew near, a loud snap could be heard as tree roots gave way and the ground caved in. Celestia and Luna quickly extended their wings, trying to fly away from the wreckage, but the falling trees and branches caught them and dragged them down.
A few hours later Celestia woke, moaning in pain as she softly closed her hurt wings. She sat still for a moment, letting the dizziness in her head calm down a bit before opening her eyes. She noticed a light in the dark, and began moving toward it. She paid no notice to Luna, who had just woke as well. She felt her legs go numb as the light grew closer and closer, until finally she saw it. A cave, with a tree of pure crystal.
"The Tree of Harmony." Luna gasped in awe. "For once, the mystic was speaking literally."
Celestia continued to gaze at the tree, lost in it's beauty. Both her and Luna were so entranced that they didn't notice a silhouette enter the cave. The silhouette carried a basket, and set it down near the entrance of the cave. A voice called out to the sisters, spurring them out of their awed state. "Please, take care of it." Celestia was the first to turn, but the silhouette was already gone. The basket began to shake on it's own, and a muffled cry came from inside of it. Celestia approached the basket, and moved the blanket that sat on top. Underneath the blanket was an infant, but it was completely alien to her. It was hairless, and resembled a monkey.
"What is. . .he?" Luna asked, noticing that the baby was exposed as well.
"I. . .I have no idea. . " Celestia mumbled. "But. . .he's not what we came here for, let's get the elements and stop this 'Discord' character."
"Sister, we can't just leave a baby. Alien or not it's defenseless and harmless. It will die without someone to help it." Luna replied, giving Celestia a stern look.
Celestia looked from the elements to the baby. "Maybe we could turn it into a foal, and give it to a family to watch over for a time."
Luna looked to the elements this time and sighed. "Alright. We'll do that. We don't really have a better plan."
Each sister took three elements in their magic and began to will it to work. Celestia aimed the magic towards the baby, and imagined a young foal in his spot. The cave filled with light, and suddenly all went quiet. Even the baby's cries stopped. Celestia and Luna opened their eyes to find that the baby had turned to stone.
"N-no. ." Luna groaned, her face turning green, "We. . killed him. . ."
Celestia reached out and touched the stone baby. The stone seemed to radiate heat, and she could feel a faint beat inside of it. A heart beat. "No, not dead, just. . .stone." She explained to Luna.
"What do we do with it?" Luna asked apprehensively.
"We'll hide it. We will build a big castle, full of traps, right over the tree of harmony, and hide him inside." Celestia explained as she turned to Luna. "But first, we must deal with Discord."
In the present day, Celestia jolted awake as the memory faded. She noticed that Luna was now next to her, drinking her own glass of tea.
"Is something wrong?" Luna asked, looking to her sister.
"Just a stone baby we left buried in a castle for over a thousand years." Celestia answered, causing Luna to spit out her tea.
Quickly grabbing some parchment and a quill, Celestia began writing. My dearest student Twilight, I must ask you and your friends for a tremendous favor, meet me and Luna at the Castle of the Two Sisters. . . .