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// Just one mistake 
// Story: Stained Crown: The Elements of Disharmony 
// by EbonyDanger 
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Celestia must have teleported herself right into her bedchambers, because the throne room was empty. As soon as she had been gone, Luna and Twilight Sparkle had done the first thing that came into their mind: They had teleported themselves (and in Twilight’s case all her friends) into the Canterlot Castle.
“Where is she?”, asked Twilight worried. The other Mane Six looked around nervously. 
“Is she hiding?”, Pinkie Pie wanted to know, while she jumped around, peeking into every corner, behind each carpet and the throne, “Woooh, she is good.” A big, childish smile filled her face and her eyes glittered in excitement.
Luna responded: “We think, our sister has left to go into her sleeping quarters to get some privacy.” Her ears twitched as she looked at the empty throne, her face eclipsed with worry, “We worry about her. We never saw her crying like this or even running away from us.” 
Applejack walked up to Luna and laid a hoof on her shoulder. “Maybe yah should take with her. The sooner she gets out the better. We still have to figure out this dammit riddle.”
Luna nodded. “I shall take your advice, dearest Applejack.” Her hooves thundered over the red carpet as the Princess sprinted out of the room. Luna turned her head back and called: “You wait here! I will be back soon.” 
Rainbow Dash, who flew a few feet over the ground, shouted: “Doesn’t look like we have got something else to do!”
Celestia’s bedchamber laid deep within the East Wing of the Castle. Luna walked through the long, white marbled halls. Servants and guards walked passed her. The private chambers of Celestia could be reached if one walked through a large, deep red wooden door with two unicorn heads as the latches. There was a small staircase, which leaded towards the door, which was flanked by two ancient looking columns.
Ah, she is in there. Luna sighted in relief as she heard the soft, muffled, sobbing sounds. Her eyes were warm with sympathy and worry as she walked up the staircase to enter her sister’s room. Only to be stopped by two spears, which formed a cross, blocking her path. Oh, not again! Luna snorted furiously and rolled her eyes.
She had not seen the two guards, but now she recognized one of them immediately. The same metallic blue fur, the same white mane and the same mean glance. Luna responded it with some kind of annoyance. She was not sure, what she felt around Sharp Sword. Something was off about that guard. She felt uncomfortable, unsure, but also annoyed by his behavior.
“Sharp Sword”, Luna demanded, “Let me in! I must talk with my sister.” 
Sharp Sword narrowed his eyes and jerked his head upwards to look bigger as he explained: “Her Royal Highness, Princess Celestia, had given strict orders not to be disturbed by anyone. She also added that there is no exception to this rule.”
Luna panted in shock and anger. “But I am her sister!”, she called. The Alicorn lifted a hoof to push down one of the spears. Sharp Sword hold against the pressure. He leaned forwards and put his ears back, curling his lips. 
“No exception!”, he repeated once more. The dry hiss made Luna feel his breath on her face. 
Luna responded his glance. She shivered as she saw the hate in his eyes. Because Sharp Sword believed Celestia would not come out, he dared to show the Princess of the Night, what he truly felt for her: Unrestrained resentment. But why? What did I ever do to you? They had no past, no issues. So where did the hate come from?
Luna called softly: “Celestia, may I come in?” 
She heard a tearful cry: “No, Luna! Leave me alone.” 
The blue Alicorn lowered her head. She sighted and closed her eyes. And I thought I am the one with the problems. It was like falling back in time again. But this time she was Celestia, who stood in front of the locked door of her younger sister.
Sharp Sword smirked slippery. “You have heard it yourself, Princess”, he said and pushed his spear deeper into Luna’s coat to get her away from the door, “Princess Celestia wants to see absolutely nopony! Not even you. So why don’t you just get out of here?”
Luna’s horn flared to get rid of the spear near her neck, when the door opened. Celestia’s horn glowed and she made the spear flung backwards out of Sharp Sword’s grip and catapulted it away. “Enough of this, Sharp Sword”, Celestia declared. Her voice still sounded a bit shaky and there were tears in her eyes, but she still managed to put on the mask of the perfect ruler. “I said, I did not want to be disturbed. That did not mean, you are allowed to threaten my subjects leave alone my sister.”
Luna looked at the lieutenant. The unicorn stumbled as he came to his feet. He bowed in front of Celestia and pressed a hoof against his chest, a gesture of obedience. “Forgive me, your Highness.” His voice sounded deep and sweet with remorse. “I just wanted to make sure you are well rested and have time to calm down over whatever shook your confidence. It seems, a younger member of the royal family” – he glanced towards Luna – “does not want to allow you to get your rest. She seems to be rather impatient.”
Luna panted in anger. You, you ruthless, slippery rat! Luna once again repeated the movement Cadence did, when she was caught up in stress and anger. She moved a hoof in front of her chest and breathed out. The Alicorn closed her eyes. Calm down, Luna. He is not worth of your temper. He isn’t worth it.
The blue mare decided to ignore the lieutenant the best she could. Luna looked up at her sister and placed a wing over her shoulder. “I was worried about you”, she said and snuggled herself against the white Alicorn’s flank, “Not only me, but also Twilight and her friends. It is uncommon to see you run away like this, busting out in tears. Discord’s riddle seems to have taken you harder then anyone of us.”
Celestia let out a shaky breath and shivered. She looked at Luna, her dawn coloured eyes still clouded by tears. Her voice trembled as she responded: “That is because I fear, I know the answer.”
Luna’s ears perked up and she asked excited: “Really, what is it?”
“A secret, I should have told you long ago.”

***

Twilight and her friends were walking around in the throne room. “I guess, we all know, what the first line of the riddle means.” The purple unicorn stopped and pointed at the glass window behind her. It showed the dark mare with the silver armor. It had been the same window, Celestia had been looking at so often. “An old enemy from the past. This must be Nightmare Moon! After all, she had created the Nightterror before and now Ponyville is plagued by the same disease as Canterlot one thousand years ago.”
“We all see your point, darling”, responded Rarity. She had sat down on a small, golden chair with red pillows. Using her magic, she directed a crest to comb her mane and tail. “It was not really hard to figure that part out. It is the most obvious after all.” 
Fluttershy mumbled: “But what does the next part mean? A sin committed by someone who seems without any flaws.”
Rainbow Dash flew slow circles around them as if it could help her to keep tracks on her thoughts. “It could be Princess Luna”, she said and pointed at another window, which showed the Royal Sisters in their rebellion against Discord, “I mean, she is a Princess, a ruler of Equestria, a defeater of awesome villains and guardian of dreams! She is as close to perfection as any being can be because she is a freaking Alicorn! And from all the ponies it was her, who transformed into the wicked Nightmare Moon! That makes total sense!”
Twilight looked up to meet Rainbow’s glance and responded: “I am not sure. The tale said, that the younger sister, Luna, became resentful. It shows that she is not perfect. She has feelings like everypony else. She could be the one without the flaws, but I do not think, that Discord meant her.” 
Applejack trotted towards Twilight. “But who else could it be?”, she asked, “Besides what do the last two lines mean? Bring back, what belongs together? I have no clue at all!” 
Pinkie Pie hopped around the farmer and responded: “Then better think fast! We have to get this riddle down. If we don’t, then Applebloom will have more nightmares and torments and will die, because she cannot handle all the bad dreams and coughs!” As usual, the pink earth pony spoke rather fast, when she was connecting a thought with a long line. 
Applejack shot Pinkie an angry look. “I know, Pinkie. I do not need the worst case scenario!”
“No problem”, she responded with a big smile. Applejack looked like she loved to smack Pinkie in the face.
Twilight saw the tension and carefully used her magic to push the two of them apart. “Listen”, the unicorn addressed Applejack, “We know that you are sick with worry. We also know that Applebloom could die. We understand your anger and grief, Applejack. But Applebloom is still alive. Don’t meet trouble halfway! The worst has not happened yet. We still can save her. We only have to figure out the last part of the riddle.”
Rarity threw herself on a red, luxury couch that appeared out of nowhere and whined: “We have not even figured out the half of the riddle, darling. Oh, this is dreadful! If the disease spreads, it could affect Sweetie Belle.” 
There was a crashing sound as Rainbow Dash lost control over her wings for five seconds and fell down on the ground like a stone. “And Scootaloo!”, she added and her eyes widened, “That is bad, really bad!”
Twilight bellowed in frustration: “Stop speaking of the devil and the devil shows up!” She jumped into the air, ears pulled back, panting heavily. All Mane Six were worried and frustrated. Blimey, the last thing, we need, is one of Discord’s riddle. Why couldn’t he tell us what is going on? Is this asked too much?
Fluttershy whispered and waved a hoof: “Please, everypony, calm down. We just have to overthink it again. Although I am as clueless as you. I do not know what the riddle means.” She whimpered sadly.
“I do.” 
The Mane Six looked up and gasped. “Princess Celestia!”, they all panted in surprise. The Solar Princess stood in the doorway, followed by Princess Luna. 
“You know?”, asked Twilight hopefully. Celestia sighted and folded her wings neatly on her back. She slowly walked over the red carpet towards her throne. Here she stopped and turned around.
Luna stood next to Rarity, Pinkie Pie, Applejack, Twilight, Fluttershy and Rainbow Dash. They shared worried looks. Celestia’s face was eclipsed and she seemed to be crushed down by a great pressure. Her eyes closed and she dropped her head. “The flawless pony, who committed a sin, is me”, she whispered.
Gasping sounds filled the air. Luna flapped her wings and took a step back, stunned. Her mane and tail shivered at the fast movements of her head and hips. This cannot be! What sin could Celestia have done? Maybe my banishment. Luna responded: “Tia, when you banished me, you did what you had to do. That is not…”
Celestia silenced her by lifting a hoof, still with closed eyes. “That is not, what I am talking about”, she said merely, “It is about something else. Something, that happened decades ago.” The Mane Six started to whisper and put their heads together. Luna too lifted a brow. She folded her wings on her back once more and her eyes glittered in worry and curiosity. What had her sister done in the past? It must have been something unforgivable. So bad, she did not even dared to voice it. Until now.
Celestia opened her eyes. “Twilight, you must know, that the Elements used to be twelve and not six.” 
The whisper stopped at once. Twilight’s maw dropped. “Twelve?”, she stammered, “How is that possible? I studied magic for years! I know everything about the Elements of Harmony and not a source mentioned them as twelve. Always six: Laughter, Generosity, Kindness, Honesty, Loyality and Magic.”
The Solar Princess opened her wings and explained: “That is, because I found and destroyed the Elements of Disharmony: Gloom, Vanity, Cruelty, Deception, Betrayal and Sorcery.” 
Again, gasping and screaming sounds filled the air. 
Twilight stammered: “You…you destroyed them?!” 
Luna asked sharply: “Where did you found them?”
Celestia dropped her head. She folded her wings and sighted. Suddenly she looked old and tired. Not the beautiful, perfect goddess, but a broken, exhausted, immortal being, centuries old. Luna narrowed her eyes. To reveal this secret seemed to be more then Celestia could bear. How long had she been caring it around?
Celestia’s horn glowed golden and with a weak movement of her head, she made the Diary of Fate appear once more. What does it have to do with that? Luna blinked confused. She thought she knew every story in the Diary. Well, she actually never read the first few pages, but that was, because Celestia had told her, those were not important.
Now her older sister opened the book at the very few first pages. This story was only four pages long, It contained four pictures. The first one showed Celestia with the tree of Harmony.  The second depicted Celestia with six gemstones circling around her. The third one was an image of a faceless Alicorn, surrounded by golden light. The last picture depicted Celestia and the shattered pieces of the Elements. 
While the Moon Princess and the Mane Six looked at the images, Celestia explained: “Luna, after we had defeated Discord, I walked back to the Tree of Harmony in the middle of the night. I discovered six more Elements on its backside. Of course, I was happy first, because now the Elements of Harmony had even more power or so I thought.
I tried to wield those six strange Elements. But they did not connected to me. In fact, they defended themselves against me. You can imagine my shock. I was speechless. Something like this had never happened before.
Twilight, you and your friends must know, I can wield a spell, which allows me to see the bearer of an Element. That’s how I discovered you for example” – Twilight blushed after these words – “I used the spell and saw a vision of another Alicorn. You, Luna.”
Celestia shuddered and lowered her head once more. “I was not only shocked, I was terrified. I tried to deny, what the spell had shown me. I was sure something must have gone wrong. My sister could never wield such bad character traits. After all the tree had chosen you as the bearer of the Elements Laughter, Loyalty and Honesty. It just did not felt right for me.
I stared at those stones and I realized how much I hated them. I could not wield them and I did not allow you to wield them either, Luna. This made me so mad and frustrated. I was scared, terrified. In the wrong hooves, the Elements of Disharmony could become such a powerful and dangerous weapon. I decided to prevent this fate for our nation. We hardly had rescued Equestria from Discord and we could not face another war. I was sure of that.
Therefor I decided to destroy the Elements of Disharmony. I used all my magic to shatter these six gemstones in the hope they would never be used or heard from. Only the Element of Sorcery survived my strong efforts. I decided to get rid of it on another way. I ordered the best forger to create a necklace for this Element with an unicorn head and Pegasus wings. I sold the Element of Sorcery to a ridiculously high price in the hope no one could ever buy it from the merchant. I also wrote the story of the Alicorn Amulet – the fake name of the Element of Sorcery – and told that it could corrupt and was highly dangerous. I hoped nopony would ever achieve enough money to buy it and use it. I hoped it would be forgotten just like the other Elements or become a part of ancient history.” 
The ponies stared at Celestia, maws open and eyes widened. Luna felt an immense amount of rage and shock, whirling inside her. How could you be silent about this? She would have loved to scream her anger right into her sister’s face, but now it was not the right time for that. Luna just opened her wings partly and put her ears back. She jerked with her head towards the Mane Six and the door. An unspeakable order to throw them out.
Twilight stammered: “But why would you do such a thing? The Elements of Harmony are so powerful and the Elements of Disharmony could have made them even more powerful.” 
Celestia was sobbing partly as she responded: “Or they could destroy them. They could spread their dark magic over the world and throw Equestria into another war! I could not take that risk, Twilight! I was so worried. I was young; I had just saved a nation from eternal chaos. I knew, the land needed time to restore itself. If I let the Elements of Disharmony exist, this time could never arrive.” Celestia sighted and looked up. Tears streamed down her face. “I just wanted to do what was best for Equestria.”
The Alicorn flapped her wings feebly and lowered her head once more. Turning her face away, more tears ran down her cheek. “But it seems I have not learned my lesson”, whined Celestia, “I made one simple mistake and now Ponyville is threatened by Nightterror! If the disease spread, it could affect all of Equestria. Because of me!”
Luna’s rage cooled down a bit. Seeing regret on her sister’s face felt weird, strange, and almost wrong. It just did not suit her. And I thought, Nightmare Moon is a great sin. Sure, the dark force still was a great threat, but nothing compared to Celestia’s mistake. One simple change in the balance of harmony in the past had led to a disaster in the future.
Luna took a step forwards and wrapped a wing around Celestia’s shoulder. She was still crying. “Shhh”, the blue Alicorn whispered, “Everything will be alright.” 
Twilight added with absolute confidence in her voice: “Yes, Princess Luna is right. Princess Celestia, you can count on us. We will find the Elements of Disharmony and make things right.” 
“On it!”, called Rainbow Dash excited and shot towards the door, ready to begin.
“No, you won’t.” 
“What?” Rainbow Dash, who had almost reached the door, stopped in mid-air. The Pegasus gasped in confusion. Then she whirled around and flew back to Celestia. Stopping a few inches in front of her snout, she asked: “Could you repeat that?”
“I said, you won’t.” Celestia took a step away from Luna. The weak moment was gone and the perfect ruler had taken its place. The Solar Princess folded her wings. She closed her eyes before she opened them again, revealing a firm glance. “I do not mean any offence against you and your friends, Twilight”, Celestia explained, “You have done countless things for Equestria and I value that very much. But I fear, you won’t be able to find the Elements of Disharmony. Being the Bearers of the Elements of Harmony gives you a close connection to these. Strong enough to recreate them after Nightmare Moon shattered them even. But I fear, your bound won’t allow you to connect or even sense a splitter of the Elements of Disharmony.”
“Alright, great, that’s bad.” Rainbow Dash landed on the floor. 
Rarity asked: “But if no one of us can sense the Elements of Disharmony, how or better who is supposed to find them?” 
Celestia sighted and responded: “Remember my vision? I saw another Alicorn as the Bearer.” A warm smile caressed her lips as she looked at the Bringer of the Night. “I do believe that this pony has been my beloved sister, Princess Luna.”
What? Luna, who had been listening with a rather cool facial feature, now gasped in shock. She took a step forwards. “Sister, how am I supposed to find the Elements of Disharmony?”, she asked, disbelief painted itself all over her face, “I was a Bearer of the Elements of Harmony once just like you.”
Celestia lifted a hoof and pointed at her chest as she responded: “But unlike me you never denied bad emotions. I sensed a dark core within you, Luna. If I had taken it as a foreshadowing, Nightmare Moon would never have happened. That is not my point. My point is if your dark core still exists, then you might be able to find the Elements unlike me or the Bearers of the Elements of Harmony. You have gone through hell and this had left its mark on you. You have been fallen from the greatest top in heaven to Creator’s disgrace. You have tasted the light, but was swallowed by darkness. If anypony has a chance of finding those Elements of Disharmony, it is you, their rightful bearer.”
Luna made a weird sound, half sighing, half chewing, half snoring. “Yeah”, she grumbled, sarcasm dropped off her voice like poison, while she rolled her eyes. The Princess put her ears against her back. How lovely! My own sister calls me a disgrace for Creator. As if I needed another reminder of my sin.
It was not only this bitter taste of remembering Nightmare Moon again, that disgusted her. Luna felt rather uncomfortable. There was a nagging doubt in the backside of her head. Why did it had to be her? Was she even capable of finding those Elements? After what she had done? What if Celestia’s plan backfired and the Elements corrupted her and made her become Nightmare Moon once more? Had her big sister thought about that?
Luna grumbled: “Tia, we need to talk. In private.” 
Celestia nodded. “Of course.” The Solar Princess looked at Twilight and her friends once more. “Do you mind leaving us alone for today?”, she asked, “My sister and I have to discuss this matter.” 
Twilight Sparkle nodded. “Of course, Princess”, the unicorn said, “We will go back to Ponyville to watch over the younger fillies.” Her violet eyes rested on Applejack, whose face eclipsed once more with worry. “To look after Applebloom especially.”
Celestia sighted. “Very well, my little ponies”, she whispered and smiled, “I agree with this decision. Twilight, if you need anything to help the poor children, feel free to send a letter or even come to Canterlot to me.” She opened and folded her wings once more. With a shake of her head Celestia explained: “I may have made a mistake in the past, but I will do everything in my power to ease the pain of these foals.”
Twilight and her friends looked at one another, smiling. 
Applejack bowed and pressed her hat against her chest. “Thank yah, Princess”, she responded, “This means a lot to mah.” 
Rarity slowly turned around and said: “Come, everypony, let’s leave them alone. We have wasted enough of the Princesses’ time.” The Mane Six slowly walked out of the room.

***

“WHY?” Luna’s voice sounded sharp, threatening and angry. As soon as the six ponies had left the throne room, Luna had shred off her calm attitude. In a fast movement of her head, she levitated the Diary of Fate and threw it across the room. The heavy book hit Celestia’s shoulder, making her turn around.
Alarmed the guards ran into the room. Luna’s hot temper had broken through and she looked terrified. Sharp Sword took his weapon and ran forwards to charge at the Moon Princess. Other guards followed. Celestia merely opened her wings. She turned her swan-like neck around and stared at the guards. Stay back! The mare did not need to say the order.
In her fury Luna suspected Sharp Sword to disobey the order. After all he hold a grudge against her and now she threatened her sister or so it seemed. But the grey unicorn nodded and saluted. A flick of the ear and his soldiers retreated. Sharp Sword walked past Celestia and took his place at the entrance door again. He may hated Luna, but his loyalty towards the Solar Princess was undeniable. 
Luna stood in front of Celestia. Her brow was furrowed and she showed her teeth. “Thou art an hypocritical, unreliable liar! Thou lied to us! Thou lied to us. WHY?!” Luna slammed her hoof on the ground in her fury. Outside dark thunderclouds rolled over the sky and lightning painted around the Princess of the Night. Due to her power over the moon, Luna also had the ability to control the tides. Therefore, she could create massive thunderstorms and sea waves.
A strong wind howled around the throne room. He made the mane of the ponies tremble. Outside the clouds kept swirling, blocking the sun, and pressing themselves against the window as if they wanted to break the glass. Luna’s wings bashed through the air as the Moon Princess rose from the ground. Her whole body was tense. White-eyes, swirling mane and tail. Luna’s Royal Canterlot Voice thundered through the air.
“THOU KNEW THERE WERE TWELVE ELEMENTS! THOU KNEW IT! AND THOU NEVER EVER TOLD US! WHY? WE HAVE TRUSTED THOU, TIA. AND THOU BETRAYED OUR TRUST! HADN’T WE AGREED THAT WE WOULD NEVER EVER KEEP SECRETS FROM ONE ANOTHER? THOU BROKE OUR PROMISE! THOU LIED TO US! THOU LIED TO US! WHY? WHY?”
Luna’s last cry was followed by an enormous crack of thunder and a large lightning, which painted around her silhouette. She had spread her legs, arms, and jerked her head backwards. Unlike Celestia, who often refused to use the Royal Canterlot Voice, Luna had learned to perfect her own voice and use it as an instrument in diplomatic measures.  
The power of her voice had flung some guards against the wall and disarmed them. Even Celestia had stumbled backwards a bit. The clouds withdraw themselves as Luna landed on the floor. Her eyes, former white and glowing, now turned back into their sapphire state. She stood there; ears pulled back, and hang her head.
“Oh, Lu.” Celestia sighted. She trotted towards her younger sibling. Reluctantly, Luna allowed her older sister to hug her. Celestia’s swan wings wrapped themselves around her shoulder and she placed her chin on Luna’s blue mane. The Solar Princess sighted and closed her eyes.
“I am sorry”, Celestia whispered and opened her eyes a slit to peek down at Luna, who refused to look at her. “I know, I should have told you. But I was scared. When I saw you in my vision, I was gripped by such a strong fear. I feared what you could do. Maybe I was even jealous, that you could wield something I could not. I was ashamed of what I felt. What kind of sister was I to fear my own sister? But maybe I also feared for the good of Equestria. I wanted to have a glorious and happy future for my little ponies with you by my side. So we would rule in love and unity. I feared, the Elements of Disharmony would divide us and throw our kingdom into shadows. I did not wanted that to happen.”
Celestia squeezed Luna softly with her wings. Her glance directed itself towards another painted window, showing two Alicorns, sitting on thrones. “After I destroyed the Elements of Disharmony and got rid of the Alicorn Amulet”, Celestia told, “I tried to forget all about them. I wanted to erase them from my memories and from the ones of our nation. I wanted to pretend, they never existed. I thought, I could control the fate and the rules of harmony.”
Celestia laughed weakly. “I must have been a great fool, mustn’t I?” 
Luna looked at Celestia and laughed. “Oh, yes. You tried to pretend you were even more god then you already are.” Her glance brightened up. The Moon Princess leaned against the Solar Princess in comfort. 
Celestia took on her story: “I did not want to bother your mind with something that never existed. We both had our Elements to wield and I thought, if you never knew about the Elements of Disharmony, you would never miss anything.”
Celestia let go off Luna. She stepped towards another window. It showed the moment the Mane Six used the Elements on Nightmare Moon. The Solar Princess sighted. Her mane and tail trembled in the air. She dropped her ears. “When you got purified”, Celestia whispered sadly, “I was faced with the question, if I should tell you about the Elements of Disharmony. After our promise to keep no secrets from one another especially. I tried to find an excuse.” Celestia glanced at Luna and her eyes gleemed with deep love. “I was so happy to have you back after all these years of waiting. I did not want to disturb our luck with something that happened decades ago. I thought, if I go on as if they never existed, everything would be fine and you had no trouble on your soul.”
Luna responded: “It was foolish and stupid, what you did.” She flapped her wings, before folding them. “I know, you wanted to protect me, but I am no child anymore. As you have said, I had experience in a topic, you could hardly imagine. You should have told me about the Elements of Disharmony.”
The Moon Princess opened a wing and softly petted Celestia’s shoulder with the feathers. “But I can understand what you did”, Luna said congenially, “After all, we both sometimes feel ashamed of something. We both want to keep secrets, because they are personal, embarrassing, and dangerous. It is natural. And what is life without some secrets?”
Luna smiled and watched the corners of Celestia’s mouth go up as well. “Thank you, Lu”, mumbled the mare. They both found themselves in an embrace again. For a short moment, they enjoyed each other’s comfort, before Luna spoke again.
“Tia?” 
“Yes, Luna?” 
The Bringer of the Night looked up and asked: “Are you really sure I should search for the Elements of Disharmony? What, if something goes wrong? What, if I do not find all of them in time? What, if I return too late? What if I fail?” Luna dropped her head. All these what Ifs. They clouded her mind with worry and doubt.
Luna lifted her brows and added: “Besides I do not even know where to search for them. I do not know where I should go. Or even how to start. I am just not sure, if I am the right mare for this job.” 
Celestia lifted Luna’s chin with her hoof. “I believe in you, Lu”, she responded, “You are a great mare and I am sure, you are just the right pony for this mission. Your heart will guide you and the dark core in it will help you to find the Elements when you least expect it.”
Luna opened her maw to protest and voice even more worry, but Celestia softly silenced her. “Easy, Lu. The past is history. Tomorrow contains rumors. But the true present is to live the present.” Her swanlike wing pushed the blue mare closer to her. “I know, you are scared and worried. And I understand that. But those things, you have voiced, are they truly what you fear the most?”
Luna dropped her head and sighted. She felt like an open book in front of Celestia. Sisters. They knew the other one often better then they knew themselves. The Alicorn rubbed her leg with an hoof. Luna eyed the darkblue fur. In her mind, it turned black for a couple of seconds.
Luna looked at Celestia. Her words came slowly and hesitated, before they left her maw: “I fear that I become Nightmare Moon once more. You said it yourself: The Elements of Disharmony corrupt. What, if I fall back into old habits? What, if I become bad? What if I return as a monster?” She hang her head.
Celestia slowly stood up. She was taller than Luna, but now the Princess of the Night really felt like a dwarf. Her sister responded: “I never said you should go alone. You can take friends with you. I know that you are very close to some members of the Nocturnal Guard. Take them with you. They will remind you, who you are. And they can help you.” 
Luna stood up. “You are right, sister”, she responded, “I will leave at dawn.” 
Celestia nodded. “I wish, I could come with you. I mean, who should tell you how cold is it?” She softly patted Luna’s chest with a wing.
The blue mare laughed. “Tia!”, she said half amused, half serious. 
Celestia walked in front of her and stopped. “Let me tell you something, Luna”, the Solar Princess said, “A pony, who can only rely on light magic, cannot finish this mission.” Celestia turned her back on Luna. She opened a wing and peeked behind it, smirking at her sibling. “But maybe a pony, who can rely on dark magic as well, can.”
Luna huffed. Dream on, Celestia. She made a rather grumpy face. Celestia stepped forward once more. “But now you must go.” She softly touched Luna’s shoulders with her horn. “The fate of Ponyville lies in your hooves.” 
The blue mare nodded. “I know, Tia”, Luna replied, “I promise, I won’t let you down.” She turned around and left. 
Celestia watched her until she disappeared. “Travel safe, my sister”, she whispered, “Not only Ponyville counts on you, but Equestria as well.”