"Princess, I'm sorry to disturb you during your first night. I--"
"Tis not--" the alicorn sighed as she stepped from her throne, "It is alright, Captain. We simply wanted a look around, again. It has only been one day, after all. We understand the nature of things. Miss Lulamoon shall become our equal and will handle matters for us while we our given time to learn so that we may....adjust..." she looked around and the young alicorn's ears flattened just a tad, "...to all of this."
Moondancer shifted uncomfortably as the room lapsed into silence, uncertain what to say. For a moment she struggled with herself trying to figure out how to comfort her Princess, but it was not meant to be; just as she opened her mouth to speak her ears perked at the sound of hoofsteps, and she was thankful for the distraction. Luna herself, turned her attention taken away from the tapestry and the works of the castle to look at the approaching guards.
"Pray tell, who is this?"
"Princess", Moondancer saluted, "we found this mailmare on castle premise," she glanced back to the mare in delivery uniform with a raised brow. "She was circling the castle and when the guards confronted her for trespassing past normal court hours she stated she had a message to deliver to you" and then Moondancer grimaced, "but she would not tell us from who."
"Is that so?" the royal looked down at her guest. "Tell us, what is your name and who has sent you so late into my night?"
As if she hadn't heard the important part, the Pegasus smiled nervously. "This letter will only open for your eyes and your eyes only, no pony else" then after a nervous pause, the mare added, "Your er, Majesty."
Luna, now significantly smaller, at chin levels to the average pony, pondered these words as she stood elevated at her seat of power. With careful steps she trotted forward, eyes lidded, her cool and neutral expression somehow almost adorable in a pubescent teenage filly's body as she came to a stop on the steps leading to her throne.
"And why is it We should not have you ar--"
"Lockdown the castle!" a voice shouted from somewhere, interrupting Luna to her utter distaste and fury. Echoing up, from the throne room's hall: "CHRYSALIS CHANGELING HAS INVADED THE CASTLE, BLUEBLOOD'S GUARDS ARE SEARCHING FOR IT!"
And almost instantly all eyes in the room fell on to the unnamed messenger.
"...hehe" the lavender pegasus giggled nervously as she swept a lock of electric blue from her yellow eyes, "w-what are you looking at me for?"
Without a word, the four pegasus guards that had escorted her moved to block her path at the throne room doors, just as Moondancer scowled, her horn igniting while Luna oddly remained blank and expressionless.
"Wait!" the pegasus shouted, as the guards moved to surround her. "Think about it! Why would a changeling on Chrysalis's side come here?! I mean the whole split with Thorax during the civil unrest was everywhere on the papers! Coming back to Canterlot would be insane after the princesses basically threw them all out of the capital when they found out Chrysalis had been working with Lord Overcast! I can't be a changeling!"
The advance did not seem to stop. Then Luna with perfect deadpan said:
"Or you could be."
And as the pegasus mare's jaw worked to form some sentence of retort, Moondancer threw a spell out, one she barely managed to duck under as it hit the wall and fizzled out of existence.
"W-w-wait!" the lavender mare scrambled to the side of a pillar that supported the decorated ceiling, the Lunar Guard moving after her as Moondancer advanced. "I'm not a changeling!"
"If you aren't a changeling what are you so scared of?" the lunar princess asked, having never left her position from beside her throne.
"The Princess is right, if I use this spell on you, if you aren't a changeling, it shouldn't harm you." Moondancer explained.
A dramatic pause settled when the pegasus sighed. "Aureus curse us" the messenger cursed at a pitch only Luna's ears managed to hear. "Alright fine."
Stepping slowly out of her hiding spot the pegasus removed her messenger's bag, held it in her teeth as she came out, just as Moondancer relaxed her tense posture, casting a small reassuring smile as the mare began to reveal herself, then-- the pegasus leaped over the spell and chucked the bag at the nearest guard, the bag of mail taking him out of the air. Moondancer scowled, her eyes following the pegasus' path as she lined up her shot and--
With a gust of wind the pegasus was knocked out of the air, the guards flying out of the way to avoid the sudden gale to avoid getting swept away with the current. She slammed into the throne room doors, the wind leaving her sails as she gasped and with a thud she slid to the ground, groaning.
Moondancer turned to look over her shoulder, "Thank you for the assist Princess."
"Think not of it." Luna landed with a gentle flap to ease her descent as she strode forward. Landing with a clip and moving without pause across the tiled white floor, Luna stepped onto the royal red carpet stretching from entrance to throne as her four guards and her unicorn flanked her from behind, keeping pace but giving a respectable distance.
"You will tell us who you are intruder" the light almost squeaky voice of a filly doing little to make her truly sound threatening, "or you will be banished to the dungeon." Luna growled.
"Uhhhh", began one of the guards at the mention of 'dungeons,. "Princess-- urf!"
"She doesn't need to know that they've been out of use," the pegasus mare whispered into her colleague's ear. "Keep your mouth shut Glider!" and with that she removed her front knee from his ribs.
Wheezing and trying to draw breath, Glider said nothing as what might have been mistaken for a nod was actually an attempt to swallow one's lunch as it came back up.
"Ooooooh" groaned the messenger in the meantime, and with a burst of green flames the disguise vanished.
"What dost thou mean?" Luna whipped her head around, coming to a stop. The guards flinched at her sudden harsh tone. "The dungeons not in use? Preposterous, why?! All these conflicts and you have not kept prisoners of war in here, once?!" she yelled incredulous, volume reaching dangerous levels. "WHY?!"
"Well--" Moondancer started but her eyes widened when she saw movement, and before she could say "Princess!" And cast a spell-
A loud shattering filled the air as if somepony had dropped glass. The moment they turned, they were blinded with a light as the changeling vanished into the aethar.
Luna stood there, halfway at the doors, staring in jaw-dropped surprise at the vacant, empty, spot where a changeling, Chrysalis' changeling had once stood.
Then the temperature became just a bit chilly, and the majestic drapes along the corners of the walls began to shift with a cold breeze.
"P-Princess?" Moondancer stuttered.
The reply was a growl as the filly stepped forward. Luna barred her teeth, her cropped short mane gaining buoyancy by the same breeze that played with the drapes and toyed with her guards tails. Her wings peaking out in aggression, fur puffing out in a way to look almost bigger.
"No", something caught her eye, and when she looked, dark Luna looked back. "Be smart Luna." dark Luna chided in a voice that only Luna could hear, with a look of annoyance and frustration that only Luna could see. "Do not let what pushed you into craving more power than my own be your undoing before your reign has even begun."
Eyes returning back to her guards the alicorn lost some of her ire at what she saw, they flinched back but were accepting of her anger. Heads bowed, all save for Moondancer who chewed her lip nervously as she stood to the side waiting for the rule of law to be hoofed. The distraction had cost them a intruder and the princess had a right to be furious, especially if it had come to her life. She was, after all, Equestria's salvation. Discord would handle the Sun, while she the Moon. If she died, there would be nopony to help them. Discord would go back to being bedridden while he safely manipulated the stellar cycle and ensured the gears of this realm were properly managed. There would be no ticket out, no antenna to help stabilize his magical energy output, no antenna to reduce the stress of magical nature; Equestria would revert back to its state of peril and its allies would return to their states of unease, prompting new enemies as the world held its breath, hoping Discord could deal with the stress of making magic work in a way that didn't agree with him.
And it was because no pony but her and her departed sister and one chaos lord could hope to reach the heavens. For all their magical strength Sunset, Trixie, Starlight, Cadence, and Twilight were incapable of safely handling the most delicate gears magic could grant you access to. And it was because of this, Equestria, the world, would suffer.
Which was why when she'd first been told by the Unicorns who touted they wielded the heavens like drumsticks, conducting the heavens to do their whim both her and Celestia had raised their brow in silence, yet quiet disdain.
It wasn't like those four hadn't tried. All of them had tried so many, many times since the Solar Princess had died in the Battle of Fancy, at the relic, that tower Prime had built as he ruled over the ancestors of the Prench with his fellow brethren as his vassals, the Alicorn masters of Regalia. Celestia's death had brought complete panic when Overcast had returned with her body in his magical embrace and once it had become clear Discord would help things had seemed fine.
Till they hadn't.
The moment they knew the truth, they had all tried to share Discord's burden, no matter how well he had tried to keep it hidden.
It was why the project for the antenna had been the prayer the world had had answered, till the one who made it had to be removed, and with his removal, it was destroyed.
In this moment, Luna's anger fled in the face of realization.
Her death would be the end. Discord and her had talked, though brief, awkward, and tense (perhaps not for the draconequus) it had been an eye opener. He really had changed.
To have given himself for six years lifting the sun and moon, not just it but the very nature of the world for six years when his magic was better at upsetting the balance, it must have been horrible. Frustrating even. At first she had wished it upon him and so much more.
Now, she couldn't. Now that she had talked to him, now that they had briefly discussed things and she had seen with her own eyes how far he had changed, she couldn't. The mistrust, the skepticism, the displeasure and pessimism. It all fled her. Melted away.
The Discord she had known a bygone ago was no more, at least not the being of terrors he had been to her before. He was...different in ways only she and Celestia could have theorized, which is all they would have been. Theories, nothing more.
The Discord of today compared to the Discord she had known so long ago were different in their own ways of that she could not deny.
For one thing, had Celestia truly died and Discord been free, he would have capitalized on it. He would have crowned himself Prince of Ponyland and strutted around, show boating it to the world how he had in one second, conquered the powerhouse of the world.
Now, well now he couldn't do much without upsetting the balance. When it was the Diarchy it had been easy because they shared the burden the Elements had bestowed them, but when she had been exiled...
A sickening knot formed and it made her feel strange.
Now it was Discord, except with her here she had lessened his suffering. Yet, still, it came with a cost, forever ill, unable to let loose with his magic the way he wanted in a way that agreed with him, for fear of throwing the gears out of whack.
How frustrating.
And she knew frustration. She'd spent a millennia living it for every stellar cycle, of every second up on that wasteland of dust that held no air. Powerless, weak, not in control. Trapped in a realm where her power was strengthened yet where she was completely powerless.
"It wouldn't have mattered anyway Luna." The voice broke her thoughts. The dark Luna stood beside her, just at the edges of her vision. "As long as we are together, you can never die. Not in the way these mortals can. Not ever again. Not even Discord could easily undo us with our bond, now stop being petty" dark Luna said to only the night princess's ears, seen only by her eyes, "and go look at that bag of junk. I sense something."
When she blinked next, the dark doppelganger was gone.
"Princess" she turned to look up at Moondancer. "Is everything alright?" the unicorn asked carefully, anxiously.
Reigning in her anger, Luna sighed. "Yes. Everything is fine. We apologize for our behavior, we are still stressed and this--"
The doors were surrounded in a glow and the group watched as a few unicorns bearing Night Guard armor, rushed in looking around. "Princess! Princess are you alright?!" the colonel asked as her companions flooded into the room.
The temperature in the room, Glider noticed, had become oddly colder again.
"A moment ago, quite" the princess whispered her terse reply. "We are fine," Luna said in a audible, feigned steady voice, "the intruder is gone."
"There were two intruders?" the colonel asked.
"Two?" Moondancer questioned with narrowed eyes.
"A changeling infiltrated Prince Blueblood and Consort Brittle's chambers" another guard informed.
"What?!"
"Don't worry Princess" the earlier mare reassured with a raised shod hoof. "They are fine, we are still conducting searches for the changeling with Captain Tempest, Princess Trixie and Princess Starlight. Madame Brittle's changelings are also on the task Your Highness."
Relief flooding her, Luna sighed, "Thank you Colonel Brickbar, We are fine. There is something we must inspect however," the Princess eyed the bag in the corner of her vision. "Moondancer, Cool Glider, Red Sign, Cookie Cutter, Brisk. Escort your princess to her chambers, we must look at the magic this bag contains. Colonel" the Princess turned her attention to red mare, "you and your guards should be wary of these two. They carried with them spelljars, the one with us escaped through one. Be careful."
The colonel saluted.
The guards saluted, and Luna's guards marched out with her as her magic snatched the bag and together the five guards followed the little tank, the Princess of the Night Wing, out of the throne room.