Luna's Adventures Through the Looking Glass

by Bronyxy

Rating: everyone
Tags: Adventure, Princess Celestia, Zecora, Alternate Universe, Princess Luna, Drama, My Little Pony: Friendship is Magic, Nightmare Moon
Length: 7420

Why didn’t Princess Luna come to help fight off the Changeling invasion during Shining Armor’s wedding to Princess Cadence? Now we know - she was having a few problems of her own in an alternate universe where Nightmare Moon ruled unchallenged!

Why didn’t Princess Luna come to help fight off the Changeling invasion during Shining Armor’s wedding to Princess Cadence?

Now we know – she was having a few problems of her own in an alternate universe where Nightmare Moon ruled unchallenged!

Published 2017-11-04 18:50:07 UTC
Last updated 2017-11-04 18:50:07 UTC

1 The Nightmare Returns

Princess Luna stood in the gardens of the Royal Castle, looking up to review critically her handiwork stretched out majestically overhead. Artistically, this had not been a particularly good night, principally because she had not been able to focus as something had been clawing at her mind; something she hadn’t quite been able to pin down, and it annoyed her.

She was especially concerned because the day that was due to dawn would see Princess Cadence married to Shining Armor, Captain of the Royal Guard, and she didn’t want anything to go wrong if she could help it, especially with the threat of a Changeling attack. Concerns about the forthcoming wedding had swamped the dream realm with angst ridden dreams from all quarters of Equestria; everything from guards and caterers worried about arrangements, to guests worried that they would not look their best. Amongst all these mostly petty anxieties, she was a little concerned that she had not been able to find Cadence’s dreams for the last few nights.

Luna knew that she should have lowered the moon already, and she could feel the tension building between the celestial bodies, but she just wanted a few moments more to trace what was amiss. In frustration she stomped the earth with one of her forehooves and let out a grunt of exasperation; whatever was wrong would have to wait for tonight; her time was up.

With a nagging sense of disquiet she directed her magic to the moon and lay it to bed once more. In its place a purple twilight broke over the lightening sky, melting the stars away. The sun peeped over the horizon as she knew it must, but stamped her forehoof in frustration once more; she would brief her sister on what she had, or rather hadn’t found so she could be on her guard. But brief her on what? A hunch? A feeling? The more she thought about it, the more ridiculous it all seemed. Perhaps she would just turn in for bed instead without saying anything.

Celestia was tense. The whole Nightmare Moon episode hadn’t been over long and her sister had for some reason been reluctant to lower the moon; the Sun Princess would have to tread carefully. She would greet Luna as was customary for a handover discussion over breakfast / evening supper, choosing to complement her as an opening gambit and perhaps she could judge the tone of the conversation and steer it round to what had been on her mind. A fear lurked in the corner of Celestia’s mind that maybe it would not be Luna that came to greet her but a black alicorn in battle armour. No matter how much she tried to dismiss this thought as unfounded and irrational, it refused to leave her.

A few minutes later her fears were stowed away when she heard her sister’s gentle clip-clopping as she came to her supper, not wearing battle armour, but just her usual livery collar and crown. Celestia breathed an inwards sigh of relief:
“Good morning Sister. That was a beautiful display of stars last night.”
Celestia had always lacked a finer appreciation of her sister’s nocturnal artistry, and although meant as a compliment, it wounded Luna who knew it had been far from her best work. This innocent comment put her immediately on the back hoof.

“Good morning Sister” replied Luna suppressing the bitterness she felt at her sister’s comment and lapsing into the olden tongue that she resorted to when angered by her sister “Fare thee well?”
“Good, thank you. I wondered from where you had lowered the moon this morning as I did not see you at any of your usual vantage points” said the Sun Princess, trying to be tactful.
Luna took this as another dig. Yes, she had been in the gardens. Why should it matter where she conducted her duties from? What right was it of her sister to probe her? Any lingering questions she had about telling Celestia about the night’s events now lay firmly quashed.

“We were in the gardens, Sister” replied Luna maintaining her outmoded speech with no other reason than to needle her sister “Please accept our apologies for having been late in our duties” she conceded with a thin veil of grace that barely concealed the simmering sarcasm she felt inside.

Celestia accepted the apology, choosing to turn a deaf ear to her sister’s tone as there did not seem anything of immediate significance to concern herself about, and tried to engage her instead by swinging the one-sided conversation round to her thoughts and observations about the day’s wedding. Luna just looked progressively more bored and simply wanted to go to bed; she was tired and knew she would have only a few hours sleep before she had to be up in time to support her sister when the ceremony started. At the earliest possible opportunity, Luna interrupted her sister’s flow and excused herself to retire, leaving Celestia to handle the final preparations for the pomp and circumstance of the wedding; that was the sort of thing she was good at after all.

Luna trudged back despondently towards her bedchamber, still distracted by what could have caused the nagging ethereal anomalies that had lingered into the waking world. She also found it odd that she had felt so antagonised by her sister. Something was wrong and she knew it, but could not pin it down. Perhaps she just needed some rest?

She opened the door to her private quarters and stepped in, closing the door behind her. Her sixth sense stepped into overdrive, warning her that something was wrong; or was it just her paranoia? She was tired and had only a few hours to get any sleep, so dismissed it, drawing up to her vanity mirror to remove her crown.

“Hello Luna” rasped a sinister voice. Luna froze. She knew that voice. No! It couldn’t be …
“Have you missed me?” it gloated, then snapped “Well, look at me when I’m talking to you!”
Luna looked around quickly, seeing nothing out of the ordinary, then froze again. The mirror! She turned her eyes tentatively whilst keeping her head fixed where it had been pointed.
“That’s better” smirked the voice, and then added tauntingly “You’re getting warmer!”
Luna knew where the voice was coming from and whose it was, but she didn’t feel ready to face her.

“Look at me!” screamed the voice. Luna had no choice and slowly turned her head to face the mirror. As she looked, her face started to morph from blue into a one of black wearing a helmet:
“NO!” she screamed “I was freed from you! You can’t be back!”
“Reach out to me” taunted the voice.
“NEVER!” screamed Luna.
Her face could not move away from the apparition in the mirror and next thing, it put a forehoof up, forcing Luna to do the same, as if image and reflection had been reversed. She had no control.
Luna felt her forehoof raised and then reach out to touch the hoof in the mirror, except there was no glass – the hoof was real!

The apparition laughed scornfully at the obvious distress of the Princess from whom she had originally been created.
“Move over to the full length mirror!” screamed the black alicorn, her eyes staring vengefully at Luna.
“NO! You would be able to come through then!” retorted the Princess, fully aware of what the return of Nightmare Moon could mean.
“You always were weak!” taunted her alter ego “DO IT NOW!”
Luna held her ground as tears formed in her eyes due to the effort of resisting.
“Oh look at you – CRY BABY!”
“NO!” she screamed again, her nightmares all turning to face her at once.
“You’re pathetic! You’re weak!” gloated Nightmare Moon “Come to the mirror – NOW!”
Luna realised that Nightmare Moon was using a command spell and would not be able to resist without magic, so she focused on casting a counterspell, but the blue aura forming at the tip of her horn just fizzled and went out.

Nightmare Moon cackled contemptuously as Luna’s magic failed her, and she started to move towards the mirror, unable to stop herself against the pull of the magic.
“NO! NO! PLEASE!” begged Luna, all her options running out.
The black alicorn laughed louder and harder as Luna drew closer to the mirror, a plan starting to from in her mind. Luna had been banished for her sins a thousand years ago and Equestria had not faltered. If she were to disappear, life would continue as before she reasoned, far better that than allowing Nightmare Moon to challenge her sister and usurp the rule of Equestria again.

As she drew up to the mirror, her demeanour changed from one of fear to courage and she sprang forward to charge into the black alicorn. Nightmare Moon was taken off guard by this sudden reversal and tumbled backwards causing her to lose focus on the command spell she had been casting. Not only were they now free to fight as equals, but Luna had succeeded in keeping Nightmare Moon away from Equestria; for now at least.

Princess Luna’s bedchamber was now empty, but had anypony been in there they could have chanced to see two alicorns fighting behind what looked like a large mirror, but clearly couldn’t have been as it no longer reflected what was in the waking realm. Instead, it projected what was happening in another dimension, the most unpleasant one of all; the realm of nightmares.

Fear had turned to anger as Luna recognised the sacrifice she had just made. Her sister, indeed all of Equestria had given her a second chance and welcomed her back into society as diarch alongside Celestia, and she had made friends, six mares in particular springing to mind. Now she had been forced to turn her back on this wondrous new start just to fight this evil pony born of her own jealousy.

The two alicorns faced one another, legs braced and hooves dug in, firing a stream of raw magic at each other.
“You’re weak!” screamed Nightmare Moon “You’re worthless! Let me finish you!”
“No” retorted Luna her voice deepening with newly restored authority “I have been strengthened beyond what you can ever imagine with the Magic of Friendship. You have never had any friends, and never will. You know that I am stronger than you will ever be.”

The clash of magical streams began pushing back to Nightmare Moon as Luna’s words struck home, and before she could allow Luna’s good magic to overwhelm her, she broke lock and skipped deftly to one side, casting a protective black bubble around her and then vanished with a pop.

Luna stopped firing her magical aura and looked around at her new environment. It looked like her bedchamber, but not the one in Canterlot; then it struck her, it was her bedchamber in the Castle of the Two Sisters deep in the Everfree, but it had been redecorated in darker colours with pictures on the walls showing Nightmare Moon defeating Equestria, and on the ceiling a large diorama showing in graphic detail her killing Luna and Celestia. She looked away in disgust and knew what she had to do.

This nightmare was of her own making, and she was the only one who should have to face it; not her sister, not her friends, not the ponies of Equestria. She regarded the full length mirror, the portal into her world and knew what she must do. She turned, bracing her forehooves against the floor and shed a tear for what she was giving up before launching her hindlegs in a bucking action that would have made even Big Mac flinch and shattered the mirror into myriad tiny fragments, none of which could allow a pony through ever again.

She was trapped, sentenced to spend eternity in the realm of nightmares, a fate that would make banishment to the moon for a thousand years seem like a tea party by comparison; but then again, the Equestria she knew and loved would be saved from Nightmare Moon.

It was a price she felt she had to pay.

2 Help From a Friend

Luna had lost everything but an overwhelming desire to hunt down Nightmare Moon and make her pay for what she had done.

She recited a few words in her mind, focusing her mind on a spell as her horn glowed gently and then her form faded as she disappeared from view. Nightmare Moon would be able to see her, of course, but no other pony would, and that was just fine with her. She would be ready.

As there may have been guards outside in the corridor, Luna opened the doors to the balcony, gasping at the feel of the chill night air. She spread her majestic alicorn wings and launched herself into the air, headed for Ponyville. The cold was unrelenting and even the forest seemed to look pale and wan in the moonlight, like it was sick. Before long, the familiar outline of the town appeared beneath her and she descended, making a low circuit before coming in to land effortlessly in the Town Square.

Although it was night, there was nothing to hint of preparation for the next day. She had expected to see tables and chairs outside the restaurants or toys left outside the school, but there was nothing, all contributing to making the place look deserted rather than the vibrant town she knew. With nothing to see, she took off and flew to Sweet Apple Acres where she saw something that caught her up short; all the trees had withered. It was clear now; this wasn’t night time, this was eternal night!

She didn’t bother to land but kept going back towards the Everfree where there was somepony, or rather some zebra she could count on to tell her what was happening. She touched down gracefully and furled her wings, trotting the last few feet to the door and knocking.
The door opened and a blaze of light spread out before her, making her shield her eyes.

“Is this a raid from the Night Guard,
Rummaging round in my back yard?”

Luna strained her eyes to see if the zebra had been alone, but was heartened by her obvious tone of resistance.

“It’s OK Zecora, I’m a friend” she said “Allow me to make myself known.”
With this, she faded back into view and appeared a little bit off from where the zebra was looking, startling her briefly.

“You’re an alicorn like Nightmare Moon;
Do you expect me to dance to your tune?”

“No Zecora” Luna re-assured, suddenly realising that if in this world Nightmare Moon had taken over Equestria at the Summer Sun Celebration, then Luna would never have been released and was therefore unknown in this realm.
“I am not from round these parts, but please believe me when I say that I mean you no harm. May I come in and talk with you please?”

“You have manners sweet enough;
How do I know it’s not a bluff?”

“My story’s going to take some explaining” replied Luna “And a lot more believing, but if I meant you harm, would I not have done so whilst I was invisible?”

“That’s a fair comment, and makes sense;
My apologies for seeming tense.”

Zecora showed Luna into her hut and closed the door behind them, trying to rebuild some of the heat that had been lost. Luna explained who she was and how she had arrived in Nightmare Moon’s realm of eternal night. At some points, Zecora raised an eyebrow but remained otherwise impassive throughout, listening intently to the fantastical blue alicorn.

“The land is dying for want of sun,
But I fear the worst is yet to come.

The tyrant Queen must step down or fall
By persuasion or murder; your call.”

So there it was. She knew dialogue and discussion wouldn’t crack it, but if Nightmare Moon were to die, then what would become of the Luna in this dimension? It was clear that Luna was the only one who could bring about change, but could the sacrifice be justified? She knew that if she pursued the path of murder, then her decision must be absolute or her doubt would weaken her resolve and she would definitely be beaten. As she agonised, Zecora continued:

“There is no plant, herb or flower
That eternal darkness can endure.

What stocks I have remaining are few,
But there is one potion I’ll give to you;

It slows reactions and makes her weak
And will give the advantage that you seek.”

Luna knew that Nightmare Moon did not fight fair, so this potion may give her the edge she needed to defeat her. She accepted the bottle with thanks and started working on a plan which required her to ask one more favour from the herbalist; four quilted oven gloves, one of which she requested be securely fastened to each of her hooves.

With this unusual request provided, she thanked the zebra and rendered herself invisible once more, taking off into the eternally dark sky. As she approached the imposing silhouette of the castle she headed straight for the courtyard by the kitchens and dropped delicately out of the sky, the sound of her landing on the cobbled stones muffled by the soft quilted material under her hooves.

She tiptoed carefully in through the open door into the kitchen, making sure that she was never in any danger of being cornered or walked into as that would certainly blow her cover. She listened carefully to all the discussions, biding her time, catching up on castle gossip and determining the hierarchy among the staff. Once she had singled out the Head Chef, she listened intently to everything that he heard and said.

After about an hour of biding her time, her patience was rewarded when a dinner order came in from Queen Nightmare Moon herself. She watched as he sprang into action, preparing an elaborate meal that put all others from the kitchen to shame. Yes – this had to be hers. Although the order for the Queen caused much increased activity in the confined area, Luna found an opportunity to sneak unobserved across the kitchen and when the meal was nearing completion, laced the main dish with Zecora’s potion.

Standing back as far as she could, the invisible Princess watched as the different courses were loaded onto a monogrammed silver tray, each under its own dome shaped cover and waited for the delivery pony to arrive. When the smartly dressed delivery pony turned up, he picked up the fully laden tray and barged through the door into the castle, closely followed by Luna before the door swung shut again.

She shadowed him noiselessly thanks to her hoofsteps being muffled, with each turn narrowing down where he was headed until finally he arrived at the Throne Room. Luna knew she would be seen if she entered because Nightmare Moon could see through her invisibility spell, so set off down one of the corridors looking for the back way into the room. She found her foalhood knowledge of the castle from years ago had been so well etched on her memory that she had no difficulty finding her way through the labyrinth of corridors and getting to the back door to the Throne Room without difficulty. She waited and caught her breath, listening intently to any sounds coming from the other side.

Knowing that the sound of this door latch echoed in the corridor on the other side and she couldn’t teleport whilst invisible, she faded back into sight only to quickly cast a spell to teleport to the other side of the door. Once again she veiled herself with invisibility as quickly as she could; not to hide from Nightmare Moon, but in case she had company. Now she was in the same room as the evil alicorn she started to feel nervous. Had she eaten the food? Had the potion worked? Was she alone? She would only know if she went to investigate. She reminded herself what Nightmare Moon had done to this land and to her, and felt pumped, ready for action. She moved forward up the passageway for what could only be a confrontation. Perhaps she could find a way to get Nightmare Moon to relinquish her hold on the good alicorn that lay imprisoned inside her, but she would have to be prepared for events to take a turn for the worst. In this case, she would defend herself to the death.

She tiptoed down the corridor and paused where it entered the back of the Throne Room to look around. Nothing. From her perspective, she could see the back of the throne and the silver tray to one side, one of the plates spilled onto the floor, but it was quiet as far as she could see, so she edged out cautiously.

As she drew closer she became aware of a muffled sound coming from the throne itself and arced round to get a better view. She could make out some jerky movements, and finally moved forward to confront her incapacitated alter-ego in a showdown that would see the evil Queen deposed. Her anger converged into the moment and she lit her horn, spell at the ready, rounding on the struggling character sat on the throne.

As the figure came into her view she stopped still and gasped, her eyes opening wide. It was the delivery pony, struggling in mild spasm on the throne. Completely disorientated she stepped back and the light on her horn sputtered out. She had been tricked!

Wild cackling laughter echoed around the ceiling coming from everywhere and nowhere at once.
“You ignorant foal” it glowered contemptuously “Your attempt to poison me failed. Instead you have killed the waiter! How does that rest on your conscience, Luna?”
Luna stood dumbfounded. Nightmare Moon knew how much she was plagued by her guilty conscience and twisted the knife into her shame.
“Look at him writhe in the agony you clearly meant for me! Did you not consider that I may have a food taster? I have always found it to be a good motivator among the kitchen staff, and now it has helped me to catch you!”
“You will not prevail, Nightmare Moon!” shouted Luna, her head turning in different directions, chasing the source of the voice as it flitted around the ceiling, desperate to see where it was coming from.

Luna trotted quickly over to the delivery pony, bending down to run a hoof gently down his mane and whisper a brief apology, before hearing a clatter of hooves landing so close to her that she felt the rush of air.
“How touching” dripped Nightmare Moon with heavily laden sarcasm “Such a shame you killed him!”
Just as she could see Luna winding up her magic for a fearsome assault, the black alicorn stood back in a pose of defeat, completely deflating Luna’s wrath.
“I have something to tell you” said the evil Queen quietly “I’ve got you a present.”
“See these two swords” she continued, drawing them both slowly from their scabbards “I had them specially made for your sister. In fact I summoned you here to watch them in action.”

The two alicorns circled round each other while Nightmare Moon continued her monologue.
“You see, they have been enchanted with arcane magic to relieve immortals from their burden of eternal life. I was going to call back Celestia from her place in the sun and slit her throat with one, just so you could watch her die.”
“You’re mad Nightmare Moon” growled her blue adversary.
“Why should you care Luna?” asked the evil Queen “She doesn’t care about the night sky. She keeps tabs on you because she doesn’t trust you …”
“Enough!” shouted Luna “My sister loves me!”
“Really?” goaded the black alicorn “Just like this morning, when thou hadst a spat at her?”
She emphasised the form of outmoded speech that Luna had used to needle her sister; she must have been watching.
“Bring back my sister!” demanded Luna.
“Well, technically she’s not your sister, not in this dimension” said Nightmare Moon “Once you watch me kill this one, I shall find a way to get back into your dimension and kill the one you know; but you won’t be able to stop me because you’ll be dead too!”

Luna had heard enough and fired a bolt of magic at the evil Queen who was now stood by her throne, only to have it countered by a stream of evil magic as the two locked in contest of magical power. Nightmare Moon had counted on her goading having caused Luna’s self-doubt and guilt to undermine her strength, but as the magical charge drove towards her, she knew she had miscalculated and at the last second broke lock and sprang away, dropping one of her swords with a clatter onto the stone floor. She reacted fast before Luna could make a grab for it and fired another volley of magic, taking to the air cackling insanely.

Then she broke off the attack again and dived straight down toward Luna with her remaining sword pointed at the blue alicorn with murderous intent. Luna dodged at the last second and Nightmare Moon crashed onto the floor coming to rest near the throne and fought to regain her balance, keeping Luna firmly fixed with her stare while reaching round to pick up the other sword; but it wasn’t there. She padded around with her forehoof, fumbling around trying to trace where it had got to, but didn’t dare break eye contact with Luna and give her an advantage.

As she cast around for her blade she taunted Luna some more:
“I’ve changed my mind” she sneered “I’m going to kill your double too. Won’t it be simply delicious to watch yourself die?”
Luna froze. “Where is she?” she gasped.
Nightmare Moon tensed ready to strike, but couldn’t resist one more jibe “I banished her to the moon a long time ago. Do you remember how lonely it was there? Can you even begin to imagine how long I intend to keep her there this time?”
“So you’re pure evil?” gaped Luna.
“Of course; that’s why I am invincible. She was too weak with her conscience and her guilt, so I rid myself of her and now I have none of her weakness to hold me back!”

Nightmare Moon made ready to pounce, but before she could, she felt the sting of missing sword’s tip as it penetrated her flank. She looked round to see the delivery pony staring at her with sword in hoof, continuing a slow-motion thrust towards her.

“NO!” she screamed, dropping her other sword in shock and backing away.
Luna stepped forward and grabbed the fallen sword, forcing the terrified Nightmare Moon down onto the stone floor, pushing its tip into the flesh covering her heart. Knowing this dimension’s Luna to be safe, she now had no reason to hold back.

“You wouldn’t dare!” screamed the black alicorn, her eyes wide in horror.
Luna did not waste words but thrust forward, burying the length of the sword into her chest and watching as blood started to pulse around the entry wound, then she pulled it out and blood spurted from the hole as she tried to pull herself to her hooves, but failed and crashed onto the floor, her legs weakening already.
With her life’s blood leaking away from her she turned venomously like an injured snake writhing on the floor and shot a magic bolt at Luna, who countered it more easily than before, her adversary’s power waning.

“I am part of you Luna!” gasped Nightmare Moon “I am your darker side; you will never be free of me!”
Her breathing was growing ragged as the stone floor bore witness to the amount of blood she had lost and the pulsing spurts from her chest grew weaker.
“You will see me again” she gasped “You will never be free …”
The last few rivulets of blood dripping from her chest slowed and her breathing stopped, her eyes glazing over as she focused on a point in the distance.

3 Finding The Way Home

Luna stood watching the body of Nightmare Moon not sure if she felt relief or disgust with herself for what she had done.

She turned to see a broad grin on the face of the delivery pony and she went to help him.
“Thank you my good Sir” she praised “I should not have defeated Nightmare Moon without you.”
His expression remained fixed in a smile and she saw the starts of tears forming in his eyes and moved to hold him gently.
“I am so sorry for poisoning you” comforted Luna “It is but a slowing elixir and will not cause any lasting damage. Thank you, Sir.”

She looked back at Nightmare Moon, half expecting her to be ready to fight again or her body to have vanished, but instead it lay where it had fallen, surrounded by a sea of blood. Luna looked at what she had done and felt her legs begin to tremble as the adrenalin wore off, still embracing the delivery pony, who was to her mind the bravest stallion in all of Equestria.

Once she felt stronger, she donned Nightmare Moon’s belt and placed both swords in it, simply to ensure that nopony would pick them up and attempt to use them against her. Then she walked back down the passage from whence she had come and took a little known back route through the castle to a veranda that looked out over the darkened realm.

She focused he energy up to the heavens and the moon responded to her physic touch. Sometimes it was sluggish or petulant, other times co-operative, but this time it was eager to respond as she commanded it down to rest. Next she focused on the element with which she had enjoyed only passing acquaintance and drew upon it with all her might, dragging the reluctant orb up over the horizon and into the sky. She caught her breath as she heard alarms sounding all around; the Night Guard rushing round the castle and indeed all over Equestria to find out what had happened and keep order on behalf of their Queen.

Luna knew there was still one more task to perform and reached out to the alicorn trapped in the sun, deftly undoing the locks that held her in place and freeing her from her fiery prison. She was soon rewarded by a shaft of light projected down next to her like a spotlight from the heavens and when it faded, there stood Celestia.

There was a long pause as Celestia tried to work out who it was that had summoned her.
“It’s me Celly” said the blue alicorn “Luna.”
“Sister?” she asked, unable to take in this information.
“Celestia it is so good to see you” said a thoroughly exhausted blue alicorn.
“Last time we met was a thousand years ago when I sent you away” said Celestia, confused.
“A lot has changed” said Luna “Trust me.”
“I was at the Summer Sun celebration when Nightmare Moon imprisoned me in the sun” said the Sun Princess “Where is she? What has happened?”

Luna wept and threw herself against her Celestia, shaking with fatigue and happiness “It’s alright, it’s alright …”
Celestia wrapped a caring forehoof around her for reassurance as she became aware of the pandemonium breaking out all around. Luna pulled back and looked into her purple eyes.
“Nightmare Moon is dead. Her body is in the Throne Room. Equestria has been under eternal night for far too long under her command” said Luna in short bursts “You will need to resume your rightful place as Princess.”
“Of course” said Celestia “But where do you fit in?”
“I’m Luna from another dimension. Your sister still needs to be rescued from the moon, but for expedience I can stand in for the time being as I know what has been going on.”

However improbable she felt the story to be, the alicorn claiming to be Luna seemed genuine enough, so Celestia took charge as had been suggested before panic broke out and guards over-reacted against an excited civilian populace.

The two alicorns made their way into the castle, the first ponies they saw being two startled Night Guards standing at the main doors to the Throne Room; neither knowing what to do. Celestia broke the deadlock by enquiring:
“Well, won’t you let me in?”
Neither resisted as she opened the doors with her magic and walked in, bidding the guards attend. The body of Nightmare Moon lay where Luna had left it and the brave delivery pony sat woozily upon the throne. Celestia cocked an eye at the pony on the throne and Luna explained his part in the Queen’s downfall, the white alicorn nodding appreciatively.

The two guards stood stunned realising immediately that the order they had served unquestioningly for so long had been overthrown and changes would be very shortly coming. Celestia bade one of the guards carry the delivery pony to the sick bay for treatment and rest whilst the other was ordered to round up all those who served Nightmare Moon’s Court.

As they arrived, each dignitary gasped when they saw the Royal Sisters, each with their wings outstretched and held back tears at the sight of their dead Queen, lest their feelings gave them away. None spoke.

Once all were present, Celestia proclaimed the rule of Nightmare Moon over and re-asserted her position, not as monarch, but diarch of Equestria with her sister once more. Each was ordered to spread the word across the land and told in no uncertain terms that they would face judgement for their actions carried out in their deposed Queen’s name; but for now, all would be on probation.

Once the terrified dignitaries had scattered, Celestia summoned all of those who served in the castle to affirm the changes that had taken place, everypony from the maids to the guards. She gave each of them the opportunity to continue in their service or to leave if they did not want to serve the new regime. She was most heartened to sense the uncoiling of a tension amongst all those present and further that none expressed a desire to leave; it was clear that life under Nightmare Moon had probably not been much fun.

Deep in the Everfree, shafts of sunlight pierced through the windows of an unusual looking hut and a zebra smiled to herself.

With Equestria now back on the right track, Luna spent some time filling Celestia in on the finer details that had happened since Nightmare Moon had drawn her into this world. When the story had been told, Celestia made only one observation:
“You destroyed the mirror?” she asked.
“Yes” replied Luna “I could not risk my world being invaded by Nightmare Moon.”
“Commendable; but didn’t you say she approached you first through the vanity mirror?” observed Celestia “Could it be that mirror still acts as a portal into your world?”

With no further words exchanged, both alicorns made their way to Nightmare Moon’s bedchamber and looked around. Sure enough the large mirror remained in a thousand pieces, but the vanity was intact. With trepidation, Luna raised her forehoof and made to tap the glass, but her hoof went straight through; the portal was still open!

“Seems to me all we have to do is open it up a bit to let you through” said Celestia, lighting her horn. The yellow aura reached out to the portal and stretched it wider, opening a gap around it; a gap of purest black void that did not belong to either world, but moreover the gap between them.
“I think I’ll just close that again” said the Sun Princess “It looks like we will have to open it from both sides or you’re not going home.”

The white alicorn thought for a moment and then called for the housekeeper. Eager to please her new Mistress, she arrived within a few minutes and curtseyed respectfully upon her arrival. Celestia thanked her for her prompt arrival and enquired whether there was some trustworthy foal who could be spared for a special mission. She advised most apologetically that foals had not exactly been welcome during the reign of Nightmare Moon, but that a few of the mares were known to have kept their foals carefully secreted and had even gone as far as arranging a clandestine foalcare rota, so that each could take turns looking after the brood and keeping them out of sight.

Celestia asked if the housekeeper would talk with the mares and see if any would be prepared to help out. Eager to obey, but equally keen not to betray any long standing secrets among the staff, she curtseyed at last half a dozen times as she excused herself.

Ten minutes later, the housekeeper returned in the company of a smartly turned out older maid and her foal, a pink unicorn. When asked to speak, the maid welcomed back Princesses Celestia whose rule she remembered very well, but was a little reserved about the blue alicorn whom she did not know. She introduced her foal, who tried her best to hide behind her mother’s legs, in complete awe of the company that she had been presented to.

“Now what I would like you to do is go through this window” said Celestia to the awestruck filly “And find a grown up on the other side and bring them back so we can talk to them. Can you do that for us please?”
The foal nodded.
“The rooms will look different from the ones you know in this castle” said Celestia “So remember to tell the grown up that they have to go to Princess Luna’s bedchamber, OK; because that’s where you’re going to go in and where you’ve got to come back from, and you must be quick. Any questions?”
The foal shook her head and was given a final kiss and cuddle from her mother before being gently levitated through the mirror into a different castle that lay across a dimensional divide.

She shared one last look back towards her mother and then gingerly took her first steps to explore. She went to the doors of the bedchamber and undid the latch, walking carefully through and looking either side, straight into the eyes of a very surprised guard.
“What were you doing in Princess Luna’s private chambers?” he asked.
“Please Mister Guard, Sir” said the foal shakily “There are some ponies who would like to talk to you through the window in there.”
His mind raced. Granted, this had been an unusual afternoon; the Changeling Queen didn’t try and invade every day, but not only had a foal got past, but there were more?
“Is Princess Luna in there?” he asked, concerned.
“Yes” replied the pink foal “She’s stuck on the other side of the window.”
Now this he had to see; had Her Majesty locked herself out on the balcony perhaps?

The innocent little filly directed the guard towards the front of the vanity and what he saw took his breath away. The mirror clearly had nothing behind it, but nonetheless there was a figure he recognised very well in a room on the other side of it.
“Princess Luna!” he gasped “How did you get behind the vanity mirror?”
“Long story” said Luna “Please would you hand this brave little filly through to us?”
He picked up the pink foal and boggled at the prospect of feeding her through a mirror into a room that couldn’t exist but that already had Princess Luna in it. The filly soon clambered through the portal and into the hooves of her grateful mother as the guard stood dumbfounded.
“Now, go and return with my sister post haste please.”
The guard stammered, staring at Princess Celestia standing behind Princess Luna in the mirror:
“Beg pardon Your Majesty” he stammered “Her Majesty is stood behind Your Majesty …”
“She’s not the real one; promise” said Luna “Now go!”
“Am too!” joked the Sun Princess in mock dejection once the guard had run off, then leaned forward and whispered in her ear “Did you see the look on his face?”
The two alicorns giggled and did their best to picture the scene on the other side of the mirror when the guard tried to explain himself to the other Celestia.

Within five minutes Celestia had entered Luna’s bedchamber as the guard waved his hoof in the direction of the enchanted mirror.
“They’re in there” he whimpered.
The white alicorn walked up to the vanity and looked into the other realm where she saw her sister waving with a cheeky smile on her face, making a “cooooeeee!” sound in greeting.
“Sister” she said “Trying to keep a straight face, but failing “What have you done now?”
“Long story Sister” replied Luna “I defeated Nightmare Moon in combat and ended eternal night. Have you had a busy day officiating over the wedding?”
“Actually, we’ve fought off a Changeling invasion force headed by Queen Chrysalis.”
“Who?” enquired the Celestia stood next to Luna.

“Princess Celestia, I presume” said Luna’s sister with a smile on her face.
“Your Majesty” bowed both Celestias at once with an excess of theatricality that Rarity would have been proud of.
“Oh, cut that out” interjected Luna before the Celestia : Celestia interchange descended into farce “We have an interdimensional portal here, and you’ve both got to stretch it at once for me to get through or I’ll be stuck here.”
“I’d actually quite like to keep her” said the Celestia standing beside Luna.
“Oh” said Luna’s sister “What will you offer me?”
“Stop it this instant!” shouted Luna stamping her hoof and rolling her eyes “Honestly I thought you two would be more grown up!”

The two white alicorns looked at each other, each noticing a smirk forming on the other’s face.
“Look” pleaded Luna “We don’t know how long this portal will last, so please can we dispense with the banter?”
This brought the Celestia doppelgangers to the business at hoof and Luna’s sister enquired which spell the other would cast. Once the details were agreed, both white alicorns focused their magic onto the portal and stretched it together, watching as it opened up beyond the size of the vanity creating the very eerie sight of one room blending into the other.

“Jump now Luna!” shouted one of the Celestias “Before it collapses!”
The blue alicorn did as she was told and jumped through safely back into her own realm next to her true sister. As she did, the portal snapped shut and on both sides of the divide a white alicorn put a forehoof up to the vanity mirror and felt only glass, and saw only their own reflection. Each wished that they had more time to have spoken with the other, but both was delighted that Luna had escaped back to her true home. For her part, Luna gave her real sister a heartfelt nuzzle of the kind she hadn’t for far too long; finally recognising how much she loved her.
“An invasion you say?” said Luna.
“Yes Sister” replied the Sun Princess “But there will be time enough for catching up later. I think for now you may want to freshen up and attend the wedding reception before the bride and groom depart.”

Luna looked wistfully at the vanity mirror and gave it a reassuring pat with her forehoof. It was solid. Then she tidied herself up quickly and trotted off to perform a duty that even half an hour ago she didn’t think she would ever be able to do ever again in this realm and raised the moon.

Her duty completed, she fluttered down into the main courtyard of the castle where Cadence and Shining Armor were beginning their first dance.
“Hello, everypony. Did I miss anything?” she enquired as she landed next to Rainbow Dash under Celestia’s watchful eye.

There would be time for catching up later …