Prologue: Lunas Secret
Celestia sat there ears perked up, she was eavesdropping on her sister. Something has changed about her sister, but she couldn’t quite put a hoof on it. The only thing she could figure out was that Luna came into her room one day throwing accusations at her for stealing her precious son. Every Night Luna would come down to this room in the castle and talk, but as Celestia found out she wasn’t talking to anyone but the wall. Celestia found herself pushing her head against the door every night so that she may hear the conversation inside. Sure her sisters voice was slightly muffled, but Celestia still knew what she saying.
“I still can’t believe that she, my own sister would do this to me,” Celestia heard her sister say. If only she knew the truth about what really happened.
“I can, I mean look she has done it before. She banished you to the moon so how do you know she didn’t do that to him,” a voice said. Celestia didn’t know who it was but the sheer sound of that voice sent chills down her spine and through her tail.
‘I know I’ve heard that voice before but I can’t place it.’ the white princess thought.
“What should I do?” Luna asked, her voice made it sound like she was about to cry.
“I’ll tell you what you could do,” the voice replied “let me take over like you did before, and we can take care of her once and for all.”
Celestia couldn’t take it anymore there was talk of taking down someone and she feared it was her. Quickly opening the door got Luna’s attention. As she glared at her sister Celestia notice the shadowy figure standing behind Luna. She couldn’t believe her eyes, “What is she doing here I took care of her years ago?” she shouted.
“She’s here because I asked her to come back,” the royal purple princess replied solemnly. “She’s the one that I talk to every night because I sure can’t trust you anymore.”
“Why is that huh? Is she the one that is telling you that I “stole” your only son?” Celestia questioned.
“Actually she didn't tell me that at all,” Luna laughed “It was the guards that seen you with him as you guys walked through the front gates.”
Celestia tried to recollect her memories about this event but she couldn't. “There’s no way it was me I was in…”
“In what?” the shadowy figure asked.
“You stay out of this you dirty shadow how do you know it wasn't that...thing that took him?” Celestia yelled.
Luna looked between the two and then a confused look appeared on her face. “Cause…cause like she said you banished me to the moon so how do I know you didn't banish him to the sun?”
The eldest princess couldn't take it anymore as memories of that night began to flood her head. “Guards!” she yelled. “I didn't banish you to the moon I sent her to the moon,” she said while pointing a hoof past her sister.
“You don’t need to bring her into this,” Luna said bluntly.
“But you have already brought her into this by bringing her back,” Celestia replied. The sounds of hooves closed in on the three and the nightmare started to disapparate. “Where do you think you are going?”
“Run Nightmare I’ll get a hold of you sometime soon,” Luna started “Just stay close,”
As the guards burst through the door the wooden door the shadow disappeared. “What’s wrong princess?” one of the guards asked.
“She’s back, the nightmare that haunts us all,” Celestia replied. The guards looked between Luna and the elder sister with confused faces.
“Umm it doesn't look like her,” another one of the guards replied. Realizing what he meant she angrily stormed out of the room and teleported up to her room.
‘Impossible How could she come back? Didn’t Twilight and the rest of her friends in Ponyville banish her?’ Celestia thought.
Down in the room Luna began to talk to the guards. “I want her under close supervision she isn't allowed out of you sight understand?”
“But Princess Luna, we can’t do that if she found…” one of the guards began.
“I don’t want no buts I want this done she is talking tyranny against Canterlot, and we can’t let that happen,” Luna interjected. The guard quickly looked at the other with a pleading look for help before bowing.
“We will keep a close watch on her,” he said before turning and ushering the other guards out of the room.
Luna waited until she couldn’t hear anymore of the guards voices before closing her eyes and willing her conscious to come back, and just as she did that the shadow reappeared.
“I told you we can’t trust her,” it said.
“I’m sorry for doubting you and now we can do something together,” Luna apologized. She felt stupid for not trusting her new “friend”.
“It’s okay but first you know what must happen don’t you?” the shadow asked.
Luna looked down and her hoofs and replied, “Yes I do and you may now take over, but only during the night when I am ruler.” she felt the pain once more as the shadows figure seeped into her body, and her existence faded. She tried to think but it seemed access to her brain was block and now she knew that this was a bad idea.
“I knew you would give up sooner or later, and now it’s time for my payback,” the shadow laughed “Nightmare Moon is back everypony and this time she is here to stay.”
Celestia looked up at the starts and she felt a disturbance in the force, she hoped that her sister had made the right decision but it seems that she didn’t. Her sister once again was lost to Equestria and there was only one thing to do now. She had to get the Elements of Harmony back together again, and that meant a trip to the Tree of Harmony.