Luna wasn't usually awake during the day. But here she was, walking the hallways of the castle she shared with her sister, half asleep and squinting. She had forgotten how bright the sun could be at times.
She turned a corner. Was this the way to the throne room? She thought it was. She was tired. But she couldn't sleep right now. She had to find Celestia.
Ah, there it was. The throne room. Her memory had served her correctly after all, even in her muddled state. But a glance inside revealed no sister. The room was empty, save a few guards. One of them turned to face her, noticing the sound of the door opening. "Can I help you, your highness?"
"Do you know where Celestia is?" Luna asked.
"Last I heard, she was in her chambers."
Luna was puzzled but mumbled her thanks to the guard before leaving. Celestia wouldn't have gone to bed this early. It was only four in the afternoon and the sun wouldn't set for hours. Nevertheless, Luna began navigating the hallways to her sister's room. The polished metal of her shoes clacked against the floor. She was often too tired at the end of her night to be bothered with taking off her regalia before going to sleep, and she knew her sister was the same way at the end of her day.
She turned into another hallway, one with sunlight streaming through the windows. It hurt her eyes. With her magic, she moved her limp, disheveled mane to one side of her face to block out the offending bright yellow shiny thing. Why wasn't her mane moving? More importantly, why did it move in the first place? Maybe she should enlist Twilight to conduct some sort of research on her mane or something.
She turned into another hallway. Then another. They all seemed to blur together after a while. Luna could have fallen asleep for a few minutes while walking and not noticed. But eventually, she reached her destination. She tried for a minute to get her mane to look presentable. It wasn't presentable by any stretch of the word, but whatever. The tangled snarls would nicely complement the mess of questions and confusion racing around her mind. She yawned once and knocked on the door.
"Who is it?" Celestia called, her voice muffled by the door.
"Your sister," Luna called back as loudly as she could muster, which in this case was Fluttershy's definition of loud.
The door opened. "Luna? What are you doing here?"
"I could ask you the same thing," Luna mumbled. "You're always in the throne room at this time of day."
"Not today." Celestia sighed. "I've been doing paperwork most of the day, and I was getting stiff and sore sitting on the throne for hours on end. Now I've given my explanation, what's yours? You're never awake at this hour."
"I..." Luna faltered. "I had something I wanted to talk to you about." Her voice wavered, in part from exhaustion, and part from nervousness.
"Very well. I could use a break anyway." Celestia gestured for Luna to follow her into her room. Her bed and floor were covered in scrolls and stacks of paper with the occasional broken quill. "I'm terribly sorry about the mess."
"I don't mind," Luna said. Celestia cleared the papers off her bed and smoothed the blankets, sitting on it and motioning for Luna to sit facing her.
"So... what did you want to talk about?"
Luna looked down, not meeting her sister's eyes. "I was woken by a dream I had. Only it wasn't a normal dream. It was... it was certain memories that I was reliving." She paused, her nerves getting the better of her.
"Go on," Celestia said.
"Memories that I didn't have before. Memories... from when I was in the moon." Celestia stiffened in surprise. "I couldn't remember anything after I returned, just the transformation and being struck with the Elements, and then next thing I knew, I was back in the ruins and then in Ponyville..." she fell silent for a moment. "But I remember now. Just barely, but parts of it are there."
Celestia reached out to take Luna's hoof in her own. "What did you see? What happened?"
"You remember when I discovered that I had the ability to enter dreams, right?" The elder sister nodded. "How I found the magic as if by instinct, but couldn't understand how I knew? It turns out that I discovered that magic while banished to the moon. That's where I first found the dream realm. I just couldn't remember." Luna could feel herself trembling, overwhelmed by the discovery.
"Breathe, Luna," Celestia whispered, letting her sister calm down before continuing. "I hesitate to ask, but what was it like on the moon itself?"
"From what I can remember, it was like an empty, cold, spherical white room with no gravity," Luna answered. "It was full of magic. I could feel it. And if I focused hard enough, I could peek through the confines of the moon and see the dream realm through it. And on the rare occasion, I was able to summon a dream and look inside, but it was difficult, as Nightmare had drained my power."
Celestia furrowed her brow in thought. "So, is the moon connected to the dream realm? Is it like a portal there? I'm sorry, but I just can't quite wrap my head around this."
"I don't really understand it either," Luna said. "I'm just describing what I remember as best as I can. And... would you happen to remember a pony by the name of Cedar Creek?"
"I... I think so?" Celestia mused. "Wasn't he alive about 300-ish years ago and everypony thought he was crazy because he claimed to have visions or something?"
"Visions of a shadowy mare, who gave him wisdom to protect the ponies of Whitetail Woods from timberwolves?" Luna prompted.
"I think that was it," Celestia said. "I remember getting reports of timberwolf sightings from the Whitetail Woods, and later letters saying that the problem had been eliminated. I had thought it strange, but I hadn't thought about it again until now. It's all coming back."
"That was me."
"What?"
"The shadowy mare. I was talking to him through his dreams." Celestia's eyes went wide in shock. "He would describe the problems he faced, and I would give him guidance to fight them off. I don't think it was the first time that I spoke to a pony in their dreams, but it was the first time that it actually had any impact. I don't remember many other times though."
The sisters sat in silence, trying to make sense of these new discoveries.
"So... you were helping ponies even while in the moon?" Celestia whispered in awe.
"It appears to be so. But there was one pony that I didn't help." Luna opened her mouth as if to elaborate, but closed it again, once more breaking eye contact with Celestia.
"What happened?" Celestia asked.
"Sunset Shimmer," Luna mumbled.
"I can't hear you, Luna."
"Sunset Shimmer!" Luna blurted out, before closing her mouth tightly and turning away from Celestia. She swallowed hard, trying to push back the lump in her throat.
Celestia reached out and slid her hoof under Luna's chin, lifting her head to make eye contact. "What happened, Luna?"
"I tried to help her." A single tear rolled down Luna's face. "I saw a young filly, lost and confused. She was resentful towards you. I tried to help her, but the Nightmare was growing stronger. She told her to fight, to take more power." The tears came faster and faster, as Luna tried to force out the words. "The next time I saw her dreams, she was bent on becoming the most powerful pony in Equestria. The Nightmare had convinced her. Had the power of the Elements not kept us firmly within the moon, I have no doubt that Sunset would have been fully corrupted by her."
Having forced out her confession, she caved, shaking and sobbing. Celestia pulled her into a tight hug, cradling her distraught sister in her hooves. Luna returned the embrace, drawing strength and warmth from her sister. They sat together like that for a few minutes.
Eventually, Luna calmed down. She pulled away to look up at her sister, finding that a few tears marred Celestia's eyes as well.
"In my excitement of finding such a promising student, I ended up overlooking her emotional situation," Celestia said. "I never got the full story, but her family life wasn't the best. I think that initially, her quest for power was so she could feel more in control of her life, but it was twisted into something else, something worse." She let a heavy sigh fall from her lips. "And I should have done more to help her, to support her. You weren't the only one who messed something up in her life."
"As we've learned from Starlight Glimmer, we're often both at fault for these sorts of things," Luna said. "But clearly, we can learn from our mistakes."
"I mean, we're actually talking to each other," Celestia said with a smirk. "I'd say that's been quite an improvement."
The two sisters shared a giggle, followed by a huge yawn from Luna.
"I probably shouldn't keep you awake much longer." Celestia reached out to run her hoof through Luna's mane. "But before you go back to sleep, do you remember anything that would explain 'the stars will aid in her escape'? I saw the stars myself, but I still don't understand what exactly happened, nor does anypony else."
"Those stars were dreams," Luna replied through another yawn. "Once the Nightmare had recovered her strength, she was able to bring us back through the dream realm. But I don't know why those dreams showed up as actual stars and others don't."
Celestia nodded to show her understanding. "Very well. You should probably go back to bed now."
"Actually," Luna asked hesitantly, "could I stay here?"
"Of course!" Celestia lay down on her stomach, and Luna followed, snuggling up under Celestia's wing. It was warm. Soft. She was tired.
"Just like when we were little," Luna mumbled, already half-asleep.
"All those nights reading late after Starswirl had told us to go to sleep about a thousand times," Celestia recalled with a giggle. She gave Luna a gentle kiss on the forehead before resuming her paperwork.
The faint sounds of a quill scratching against paper lulled Luna to sleep. The moon was cold, but Celestia was warm.
The moon shone through Celestia's window. The mounds of papers that had once haphazardly covered her room had been formed into neat stacks.
"Thanks for helping me sort these, Luna," Celestia said, scribbling something on one last loose paper and adding it to the closest stack.
"Of course," Luna replied while brushing out her mane, which was flowing once more. She really needed to get Twilight to figure out how this magic hair thing worked. "Thanks for letting me sleep here. I really was tired. And by the looks of it, so are you." Luna noticed Celestia yawning and stretching out her wings.
"Yeah." Celestia climbed into bed.
"You're not even going to get dinner?" Luna asked.
"Too tired," Celestia mumbled.
"All right." Luna tucked her sister in and gently nuzzled her cheek. "Thanks again for listening to my ramblings. Sweet dreams."
"Good night." Celestia barely got the words out before drifting off to sleep.
Luna left her sister's room, carefully closing the door behind her and walking to a balcony overlooking Canterlot. All was still. The world was asleep, except for her. She didn't mind anymore. She had learned the importance of rest, of calmness, of darkness.
She closed her eyes. Her horn glowed, and she opened her eyes to the dream realm, decorated by sleeping ponies' imaginations.
Luna smiled. Here and in the waking world, she was home.