The wind howled as the large gusts whipped across the desolate landscape, empty but for a single pony. A pony who could've been a statue for all that she moved. Her mane and tail flew wildly in the wind, yet she made no move to push her bangs out of her eyes. This motionless pony was a light purple unicorn, with a darker purple mane that had mint green highlights, though, at the moment, her colors looked dull, as if her coat had faded even underneath the dust that covered her. Two paths on her cheeks were free of dust, having been cleaned by her steadily flowing, yet silent tears.
Parting her cracked lips, she forced out two words, "I'm sorry."
Nothing answered her but the storm of the unrelenting wind. She stood still for a time, watching the dust as it swirled around the few rocks scattered about the barren land. Unable to take it anymore, she sank to the ground, wailing as the strength fled from her legs, "I'm sorry everypony, this wasn't what I wanted. My village was supposed to be a gift to Equestria, revolutionary, even, not this! Not the reason the world and everypony in it is dead. Oh, Twilight, I'm sorry, you were right. You were right all along."
Suddenly, cutting clearly through the wind as if it wasn't even there, came Twilight's voice, "What you're doing goes way beyond cutie marks! Everything we do here in the past – even the smallest change – can snowball into an avalanche of trouble for the future!"
"Why didn't I listen to you?"
"A cutie mark can't take your friends away."
Starlight was silent, unresponsive as she sobbed in the dirt.
"I do know you can't do this! I've seen where this leads, and so have you!"
"I should have believed you. I knew the spell, how it worked, everything about what I did to it."
"So try again! Make new friends!"
"Why didn't I try? Why was I so stupid? So foalish?"
"Imagine all the others that are out there waiting for you if you just give them a chance!"
"When yours ended, it led us here."
"It's all my fault. Equestria is dead because of me. I murdered the whole bucking world!"
Sobbing wordlessly into her hooves, Starlight's eyes grew wide as everything in sight began to spin. The wind continued to tug harshly on her body, even as more voices joined Twilight's, pressing in around her from all sides.
"You lied to us!"
"You said cutie marks were evil!"
"What you're doing goes way beyond cutie marks!"
"Why did you take ours and not give up your own?"
"You took away the sun and moon!"
"There's no food because of you!"
"I've seen where this leads!"
"Everypony is starving! The foals are dying!"
"Equestria is dying!"
"You have magic, why won't you save us?"
"You've killed us Starlight Glimmer!"
The world spun faster and faster as Starlight stayed curled in on herself, repeating the same things over and over, "I'm sorry, I'm sorry, I should've listened Twilight, I'm sorry, I killed everypony, I'm so sorry."
In a flash, everything stopped moving, the voices vanished as if they had never existed in the first place, even the wind ceased its assault, and reaching out to cup Starlight's chin in her hoof was Princess Luna, Mistress of Dreams. Shock filled Starlight's face as she looked up, "Princess Luna...what, but how? You're dead like everypony else!"
Princess Luna frowned, shaking her head sadly, "No, Starlight Glimmer, neither I, nor anypony else has died. You were having a nightmare."
"A nightmare? You mean, I didn't kill everypony? Didn't kill Equestria itself?"
"Equestria and everypony in it is safe, Starlight Glimmer. You did not succeed in stopping the rainboom. Twilight Sparkle brought you back to the present, and the map destroyed the spell you altered. Nopony was hurt, and you are now Princess Twilight's student of friendship."
Starlight let out a huge breath, her tears finally stopping as she pushed herself to her hooves again. "Just a nightmare," she mumbled to herself, "I'm not a monster, not a murderer."
Looking at the Princess of the Night, Starlight spoke more audibly, "Thank you Princess Luna. Thank you so much for saving me from that. I couldn't have lived with myself if I had truly turned Equestria into a wasteland."
The dark blue alicorn stepped closer to Starlight, extending a wing over her, and pulling her close, "You are very welcome, Starlight Glimmer. I see a lot of myself in you. I too could have destroyed Equestria if I had won as Nightmare Moon."
A pensive demeanor took hold of the older mare's eyes as she looked down at the much younger unicorn beneath her wing. "And Starlight Glimmer, please, just call me Luna. I would not have titles stand between us tonight."
Starlight blinked in surprise before a small smile graced her features, "Of course, Luna, but only if you call me Starlight. And, you know, I don't really know too much about Nightmare Moon. I know the legend of the Mare in the Moon like every other foal in Equestria, and I got the whole eternal night thing, but not much else." A light blush colored her cheeks, "I was kinda busy stealing cutie marks and being a dictator when you returned."
Luna returned her smile, "Well, Starlight, I too had nightmares about what I did, though mine were self-inflicted in order to punish myself. Perhaps, if you are willing, I could show you the nightmare that my creation would give me every night up until a few short months ago. It might not give you too much information about what I actually did, but it could help you see that you are not alone in making mistakes that could have drastic consequences had Twilight and her friends lost."
Starlight’s jaw dropped, “Are you sure, Luna? That sounds like it could be painful for you, let alone very personal. I wouldn’t want to make you uncomfortable.”
“Fear not, Starlight, for I would be glad to show you. Though it was not one of my better decisions, I can bear watching it once more if it could help you to have fewer nightmares of your own.”
A sad smile appeared on Starlight’s face as she said, “Then I’d be honored.”
Luna did not reply, instead lighting her horn as the landscape blurred around the two ponies. They stood still, the only clear outlines as the scenery slowly took the form of the throne room of the Castle of the Two Sisters as it was over a thousand years ago.
Luna and Starlight faded to become slightly transparent as they stood on the edge of the opulent room. Luna’s horn was still lit as she spoke, “Before we begin, I should explain a little about the Tantabus.’
“The Tantabus? Is that what turned you into Nightmare Moon?”
Luna shook her head, “No, the Tantabus is something I created shortly after my return. Its purpose was to take my worst fears and turn them into a nightmare, a nightmare that it would give me every single night so that I could be punished for what I did as Nightmare Moon."
As Starlight did not reply beyond a simple nod, Luna extinguished the glow around her horn, allowing the nightmare to begin. A more solid version of Princess Luna appeared from behind the thrones and looked at a cloud of blue smoke beside her shoulder, "Greetings, Tantabus. I am ready."
The cloud pulsed and Princess Luna was enveloped in black swirls of magic. As she was enveloped by the magic, groaning in pain, galloping hoof steps could be heard getting increasingly closer. Just as the transformation was nearing completion, Twilight and her friends raced into the throne room. Princess Luna emerged from the cocoon of magic as Twilight shouted, "Princess Luna's turning into Nightmare Moon again!"
Nightmare Moon cackled, unworried, even as Rainbow Dash declared, "Yeah? Well, we've got the cure for that!"
All six of the friends' faces hardened in determination as they summoned their Rainbow Power forms. Their eyes glowed white as they enveloped the still cackling Nightmare Moon in their Rainbow of Harmony. Yet, when the colors dissipated, Nightmare Moon still hung in the air, laughing as if nothing had happened at all. Undeterred, Twilight and her friends directed their power at Nightmare Moon once again, but this time, she fought back with a thick beam of black energy. The beam made short work of the Rainbow Power, hitting the six friends and knocking them all to the ground where they lay motionless.
Starlight turned to look at Luna as Nightmare Moon landed and strode over to the prone ponies, "Did she kill them?"
Luna squeezed her eyes shut, "Just watch."
As Starlight turned back to the scene in the throne room, Nightmare Moon had just stepped over an unconscious Fluttershy, one hoof pressing on one of the pegasus' wings in the process. Lying nearby, Rainbow Dash saw this and growled, "Hey! Don't you put another hoof on her!"
Nightmare Moon turned, her draconic eyes narrowed as she bared her teeth at the cyan pegasus. Rainbow Dash gulped, fear seeping into her gaze, unable to hold up her brave facade any longer. The other five ponies were just beginning to stir as Nightmare Moon lit her horn, her turquoise magic surrounding all six until they disappeared without a trace as the moon flashed in the background.
Starlight looked to Luna again, confusion written on her face as her eyes begged for an explanation. Luna sighed, tears sliding silently down her cheeks as she whispered, "She sent them to the moon. But, nopony except an alicorn can survive on the moon. It was unintentional, motivated by the simple desire to dish out the same punishment she had received, but in doing so, yes, she killed all of them but Twilight Sparkle."
"Oh, Luna..."
As Starlight trailed off, Luna gave her a forlorn look, "Watch still, there is more."
Shaking slightly, Starlight did so, turning back in time to see Princess Celestia enter the throne room. Not giving her sister a chance to speak, Nightmare Moon shouted, "The Elements of Harmony are gone, as are the six ponies you sent to defeat me! You cannot win this time, Celestia! The night shall last forever!"
The dark alicorn's cackling began anew as she lit her horn again, firing a blast of magic that met Celestia's. The two strained against each other for a few moments before Nightmare Moon suddenly fired another blast at a statue behind Celestia, diverting her sister's attention for a few seconds. Seconds enough for her beam to envelop Celestia, causing her to disappear as well. Unseen, never to be seen again in Equestria, the sun flared as it gained an occupant.
As Nightmare Moon reveled in her victory, Luna lit her horn again, stopping the nightmare and changing the landscape to the open field beside Twilight's castle in Ponyville. Starlight sat shakily on the grass, and, after a moment, Luna joined her. The two ponies were silent for a while before Starlight gently laid a hoof on Luna's shoulder, "It's alright, Luna. Just like you told me, neither you nor Nightmare Moon ever did any of that. And I don't think anypony who knows you would believe that you could do such things to your friends or to your sister. Like you said, it was just a nightmare. And thank you for showing it to me. Thank you for trusting me enough to show me."
Luna raised her head, a small smile taking the place of her tears, "No, thank you, Starlight. Thank you for understanding. I hope seeing that helped you to feel less alone in your fears. As Nightmare Moon, if what I just showed you had really happened, then Equestria would have ended. Similar to your own nightmare, just as a frozen wasteland instead of a desert."
Starlight nodded, "Yes, it did help me actually. Or, mostly, anyway."
"Oh?"
"It's just, I'm still unsure if I should really be Twilight's student. Going from trying to enslave a village, to almost destroying Equestria, then to studying friendship just seems...huge, I guess. Like I should be imprisoned or put in an institution for a while to make sure I won't go all evil again. And besides, I don't know anything about friendship. Sure, Twilight and her friends all are willing to give me a chance, but anypony else? Even if they don't know what I did, I wouldn't even know where to start."
As Starlight paused to take a breath, Luna wrapped a wing around her, "I'm certain that Princess Twilight will be very proud of you."
At Starlight's incredulous expression, Luna laughed, "Starlight, don't you see? You've already made a friend all on your own."
"I have?"
"Me, Starlight. I would love to be your friend, if you would have me, that is."
Luna's vision turned purple temporarily as she was engulfed in a hug. Easing herself back so that she could breathe, Luna smiled, "I take it that this means yes?"
"A thousand times yes! Of course I'd love to be friends with you," Starlight exclaimed joyously.
Luna was about to reply when she felt her hoof slip partially through Starlight. "It seems our time is up. You are about to awaken, but if you ever want to talk, or even just visit, Spike can send a letter for you."
As she returned to consciousness, Starlight managed to say, "Thank you, Luna. I'm glad that you're my friend."
"Me too," Luna said to herself as she reappeared in the dreamscape and turned to search for anypony else who needed her help.