Princess Luna walked through the castle without saying a word, just smiling occasionally to the servants and guards as they passed. Finally, she arrived at her destination; the elegant gold sun emblazoned into the white doors identified the place as the royal bedroom.
“Good evening.” The guards greeted her with a bow. The pair of unicorns stood at either side of the door like statues, but their tone was far from cold. “Where are your guards?”
“Are you suggesting I need constant supervision?” She replied harshly.
The guards tensed visibly, the younger of the two even felt beads of sweat forming on his forehead. “F-Far from it, I just- we- uh…”
The princess just shook her head, her starry mane waving in an unseen wind. “No, it’s… I shouldn’t have spoken like that.” She breathed out, and then inhaled deeply, so when she spoke again her voice was warmer. “My apologies, it’s just mild stress.”
“Is… is everything alright?”
“Yes, I just wish to retrieve something from my sister’s chambers.”
The guards opened the doors and the dark princess quietly stepped inside.
*****
A few minutes later, the night princess greeted the guards in front of her sister’s bedroom.
The guards lightly shook their heads, looked at each other, and back. They looked mildly disoriented, unsure of what to say, until one of them settled for asking. “Did your Highness find what you were looking for?”
This time it was the dark royal who looked confused. “What are you talking about?”
The guards looked at each other again, and turned back to open the doors.
With flawless timing, when the doors opened, standing in front of Princess Luna… was Princess Luna.
Like a mirror, both of them gasped and opened their eyes wide. However, the one inside the room, with a hoof-sized bag tied around her neck, reacted first; with a powerful beat of her wings, she sent a gust of wind that knocked the guards flat on their backs and distracted the other Luna long enough to run away.
“Stop her!” Ordered the second Luna, using the loudest voice she could manage, breaking into full gallop to chase the first one. “Thief!”
Both of them were swift; the first would snake and weave her way through the corridors and the guards that stood in her way, then the second one would gracefully hop over the very same guards, so that the distance between them remained the same.
They reached a hallway leading to one of the highest towers and, since it was long and completely straight, the second Luna fired a spell at the first. The silver beam of light struck square on the left wing and a disturbing crack was heard, the fugitive rolled down, crown knocked right off of her head, but still immediately tried to reach for a window.
“Halt, imposter!” The second, or ‘true’, Luna fired another spell to paralyze the thief. The windows had been enchanted to open only for the royals or the guards, and with that broken wing she wouldn’t be escaping that way either, however, it was impossible to predict what a thief this bold could do next.
“Surrender and return what you have stolen.” She ordered, giving the deceiver the chance to repent; she was confident in her spell-casting abilities, so the imposter should be immobile and only capable of speech.
The thief sighed and, to the princess’s surprise, looked at her with teary eyes. “I’m sorry princess, I really am, but that is the one thing I cannot do. I have my mission; neither you, nor your sister can do anything about it.” Her left foreleg was trembling.
The guards that had witnessed the chase poured in and were about to surround the downed fake Luna when she stood up, causing the real Luna to reflexively extend her wing in surprise to order the guards into being cautious.
“Even without a wing, I can still survive a fall from this height, you know?” Said the thief. “But it turns out that, compared to any pony, I heal pretty fast.” She tapped her hoof down and black smoke broke off from her shadow and flooded the corridor. Contrary to what everypony believed possible, a window opened.
“You won’t miss this anyways!” She yelled.
Luna wouldn’t take any of that, and dove after the thief. Whatever that spell had been it hadn’t affected her in the slightest, it didn’t have enough power.
She couldn’t believe the thief had actually opened the window and jumped, but a dark figure swooped past her. The thief had indeed healed. No matter, she opened her wings and gave chase.
Both the princess and the duplicate flew through the air with such grace, it would surely marvel onlookers, but the intricate path weaved through the towers in such a way it would be difficult to follow with eyes alone.
Luna couldn’t help but note that the thief was very agile, just like her, it really was seeing herself fly! Yet something was off, she kept firing spells at the imposter, but the thief neither retaliated nor defended, opting instead for pure evasion. The fake had just shrugged off the paralysis spell, but hadn’t done so with the first one, so all that she could do was hit her hard enough to knock her out and pray that she could catch her fast enough as to avoid having to find out whenever or not the fake’s claims had any truth to them.
Some pegasus guards from elsewhere had seen, and took off to approach the scene. The imposter was going to get out-numbered, and if she was unwilling or unable to use magic she wouldn’t be able to get out of that situation.
The thief was flying straight to the side of the mountain. Luna focused as much as she could; most likely, the thief would dodge right at the last second and try to throw her off, thus she had to pay attention to the direction and follow closely so that the guards had time to arrive.
The thief didn’t change directions and disappeared into her own shadow.
Luna stopped as fast as she could, eyes scanning the wall of solid rock for any clues of her target…
Nothing.
*****
Princess Luna returned to the castle, eventually, to check on the guards that had stood beside her when the black fog rolled in.
Her older sister, Princess Celestia, had just finished her own inspection. It had, indeed, been a spell; a disorientation spell to render the guards unable to follow the fake princess, even through their armor. The princesses couldn’t help but notice that, had it been powerful enough to truly affect the real Luna, the effects on the guards would have been so severe they would have needed hospitalization.
Whatever she stole was valuable enough to risk cantering into the most heavily guarded part of the castle… and yet she wouldn’t risk hurting the guards? And something that wouldn’t be missed?
Celestia and Luna inspected the room, but nothing seemed to be out of place; whatever it had been, the thief knew exactly where to find it. There were hoof-prints on the rug next to the bed, though, which led right to the nightstand where Celestia kept some personal objects.
Celestia used a spell to see who had touched what last.
Bottom drawer, opened by Celestia herself.
Middle drawer, the same.
Top drawer, the thief hadn’t touched that either.
However, something reacted to the spell. A bottle of ink artistically crafted with a lion’s head, something she had had for… a few thousand years, actually. It was a pretty interesting bottle, having been enchanted so that gunk doesn’t form on or in it and to be practically unbreakable under normal circumstances by… wait… it had always been like that. Now that she put thought on it, she just remember having found it and keeping it, not actually buying it or receiving it.
A second spell revealed that it wasn’t the same bottle; it was enchanted similarly, although the ‘unbreakable’ spell didn’t feel as powerful, but trying to look into its past further than the minute the fake had placed it on the stand was impossible.
The thief stole the original bottle and left a new one behind.
And what’s more, she had made the new one after finding the original, which meant she hadn’t prepared… but why? Did she know what to look for, but not the shape it would have?
Twilight had said something about hearing a noise in the library once, but seeing nothing and not noticing anything that was out of place, and she had not been the only one... there had been other, similar incidents. This demanded further investigation, perhaps the same trick was done? And to what purpose?
=====
“Alright, what shall be our next step?”
“We wait; the traitor won’t be able to hide.”
“Should I tell Twilight and the others?”
“Uh… that’ll be an interesting conversation.”
“…”
“Meh, sure, why not? I mean, I think it’s overdue.”
“Thanks, princess.”