Luna walked down the halls of Canterlot Castle, fully appreciating everything around her. The great palace had improved considerably in appearance since her absence. It had become a beautiful piece of architecture. She sometimes doubted whether she really belonged here. She looked out at the sky through a window. It was nearly time for her to raise the moon and bring out the stars. She would have to walk all the way back up to the balcony where she and Celestia usually raised and set the moon and sun respectively.

As she traversed the great halls of the castle, she couldn't help but feel like she was being… watched. It was unsettling to say the least. She shrugged it off as she continued through the palace, occasionally greeting guards a she walked. It was strange though… the guards were few and far between, and the ones that she saw sometimes looked at her as though she were a stranger. She couldn't blame them really. She had been gone for over a thousand years, and she never thought of herself to be particularly memorable. Not like her… other self.

A fell breeze suddenly sent a chill down her spine, making her shiver apprehensively. Why was she suddenly so nervous? It wasn't like her, especially when she was alone.

Eventually, she made it to throne room, and was about to head for the balcony to raise the moon, but stopped in her tracks when she saw a silhouette standing at her destination. At first, she thought it was just Celestia, waiting for her to stand by her side like they did so many years ago. "Sister?" she called, but the silhouette gave no response. She stepped closer. There was something eerily familiar about this figure. "If you're not Celestia, then who are you? Answer me."

The silhouette chuckled ominously at first. Luna shuddered at that alone. That laugh was truly frightening. "Do you not remember me, dear Luna?" alicorn mare asked. Slowly, she turned, her eyes glowing with an evil light. "I'm hurt. Did you truly forget the mare that was created through your heart?"

Luna's eyes slowly went wide as realization dawned on her. She backed up, fear gradually beginning to consume her. "N-no! It can't be you!"

"Oh, it is," the dark mare said with a sadistic laugh. Luna shook her head in disbelief. Not knowing any other solution, she turned and galloped away as fast as she could, that evil laughter chasing her all through the castle. Every guard she passed this time did not greet her. They gave chase as soon as she passed them. Their normally golden armor was replaced by cold-looking steel and black plates, and they all now had fangs in their mouths.

"Celestia!" Luna screamed for her sister again and again, but never once got an answer. She kept running, that maddening laughter still flowing into her ears.

Soon, she made it out of the Canterlot Castle… only to be greeted by a desolate Canterlot. She looked on in horror as the ponies of the once fair city cowered and ran for their lives. How did this happen? What was going on?

Soon enough, the terrified ponies took notice of her. Their looks of fear became expressions of hatred. "There she is!" one shouted, pointing hoof at her accusingly. "She's the one who did this! We can stop her while she's weak!"

Everything had just gone from horrible to completely terrifying. The hordes of outraged ponies marched closer and closer to her. She backed up several steps, and soon bumped into something. She yelped in fear and backed away from the swarm of guards that had appeared behind her.

All the while, that horrible laugh continued to ring out. She laid down on the ground, trying to cover her ears to protect herself from that voice she feared so much. "Please…" she begged, tears streaming down her cheeks as she cowered. "Please, just stop!"

Her pleas went unheeded as the voice continued to taunt her. That horrible, horrible voice that she was so foolish to listen to a thousand years ago. The voice of Nightmare Moon roared with villainous glee as Luna pleaded again and again for it to stop.

-o-

She screamed as she shot up from her bed, drenched in a cold sweat. The dark blue alicorn gasped as her heart pounded in her chest. It felt as though it was going to explode out her body. She placed a hoof over her chest in an effort to calm herself. It was just a dream. A very bad dream.

"Princess Luna!" a guard shouted as he knocked the door open, completely disregarding the night princess's privacy. Three other guards stood behind him, all ready to jump into action if it was called for. "We heard you scream! Are you all right?"

"Y-yes," Luna answered hesitantly. "Just… a dream. Forgive me for wasting your time, Sir Knight."

"Are you certain?" the guard inquired. Luna nodded and motioned for the guards to leave her chamber. When they were gone, she sighed. Despite her role as the Princess of the Night and a dream-walker, she never liked dreaming herself. She never dreamt of anything pleasant.

Finally calm again, she looked out her window and saw that the sun was already fairly high up into the sky. She could only assume that it was close to noon by now. She had completely overslept, and thus accidentally left Celestia with setting the moon and taking the stars down from the sky. She would need to apologize to her sister for that when she saw her next.

-o-

Celestia sipped from a cup of rather delicious tea as she waited for her food. Today promised to be a wonderful day. As one of the royal cooks brought her meal, her sister also happened to enter the room. The younger alicorn seemed rather depressed.

"Good morning, Luna!" Celestia greeted her sister cheerfully.

"It's almost noon, Tia," Luna pointed out. She blushed in embarrassment then. "Forgive me for oversleeping. I'll make it up to you. I'll set the sun for you today if you want."

Celestia shook her head. "It's quite all right, Little Sister," she said with a warm smile on her visage. "I've been taking care of the sun, moon, and the stars for a thousand years. It's no trouble, really. Besides, you've been so busy with your royal duties lately, I thought you deserved some extra time to rest."

Luna nodded her understanding. "I… thank you, sister." She was quiet then, clearly lost in thought about something, even as one of the cooks brought her food to her.

Celestia gave her younger sister a worried look. "You had that dream again, didn't you?" Luna cringed at the word "dream," proving the white alicorn correct. Luna had been having that same recurring nightmare ever since she returned to Canterlot, though it was normally not so many nights in a row. "Do you want to talk about it?"

Luna was silent for several moments before speaking again. "I-I… I don't know what's real anymore, sister," she admitted sadly, quivering as she spoke. "Am I Luna? Am I Nightmare Moon? Am I being true to myself either way? I just… ever since Twilight Sparkle and her friends released me from Nightmare Moon, I've been asking myself those questions every night and day that I'm awake. And these nightmares don't' make it any better." Tears began to pour down her face, sorrow evident in her voice. She faced Celestia, her eyes bloodshot and stinging with the salty liquid. "Tell me, Celestia… who am I!?"

She completely broke down, her sobs echoing throughout the dining hall. Celestia stared at her sister in genuine shock. She had never, ever seen her so… broken. So hopeless. It pained her to see her like this. Gently, she stretched out her wing and wrapped it around Luna, pulling her in close. The younger mare pressed her face into her sister's chest, letting her pain spill through her eyes onto the white alicorn's pure coat.

"Luna…" Celestia said in a calm, comforting tone. "Shh. It's okay. It's okay." Luna's sorrowful eyes continued to spill the liquid pain. It was painful for Celestia to see her beloved sister like this. She nuzzled the other alicorn's mane comfortingly. "Do you want to know who you are?"

Luna looked up at her sister, sad hope in her blue eyes.

"You are my sister. And no matter what, you always will be my sister. I love you more than anything, Luna. Never forget that."

Luna stared at Celestia with wide, awe-filled eyes. The floor then suddenly became very interesting to her. After several moments of silence, she finally said, "Thank you… sister."

Celestia nodded and released the younger alicorn, who scooted back to her original position at the dining table. The Princess of the Sun smiled at her sister. "I believe you may need a break from all your hard work of late."

"What?" Luna questioned. "You mean… a vacation? From royal duty?"

Celestia nodded. "Exactly! I'm sure Twilight would be more than happy to accommodate you in Ponyville."

"B-but, sister-!"

"Ah-ah, I won't take no for an answer," Celestia said with finality, while still managing to keep a mischievous smile on her face. "You need a vacation. I think some time away from Canterlot might do you some good. It should be nice to get out of this stuffy old town anyway."

Luna sighed in defeat. She knew that once Celestia made up her mind, there was no changing it. "Very well. But if something important comes up that requires my attention as well-!"

"Don't worry, Lulu." Luna turned beet red at the nickname that Celestia had given her when they were both young so many centuries ago. "If something comes up, I'll let you know, all right? But I doubt it'll be something that I can't handle. Just relax, Little Sister. You of all ponies deserve a little R&R."

The Princess of the Night nodded reluctantly. "Okay, Tia. I'll try to… relax. Perhaps Twilight Sparkle knows of a place where I can do that."

"There you go!" the sun princess cheered. "Now you're getting the idea! Now then, with that settled, how about we eat? This lunch looks absolutely wonderful!"

"Especially since I slept through breakfast," Luna admitted, a small smile forming on her face. Celestia chuckled as they began to eat. It really was delicious.

-o-

On a cliff with a spectacular view of nearly all of Equestria, a jet black unicorn stallion with a dark red mane and silver eyes stood, watching the great land before him. He wore a black cloak that had a moon with the head of an alicorn mare emblazoned on the back around his body and silver armor on his hooves. He scanned the countryside, judging if it was a truly worthy land for his queen's soon-to-be capital.

"Milord," called the voice another stallion, a pegasus wearing the traditional armor of their fellowship. The unicorn turned to face the pegasus. "The others are becoming anxious. When will we carry out your plan?"

"Soon," the unicorn replied with a calm, dark, yet smooth tone. His voice was both enigmatic and charismatic at the same time. It was the kind of voice that could inspire millions and cause mass panic with just a few words. "Very soon. Tell them that we are to make for Canterlot come dusk."

"Of course, milord." Then pegasus saluted and flew off to inform his comrades.

The unicorn returned his attention to Equestria. Soon, their mistress would be revived. And soon, darkness will reign supreme once and for all.