Twilight had grown to love a good mystery and adventure, ever since that one fateful day, when she came to oversee the Summer Sun Celebration in a small village called Ponyville.

She loved the thrill of researching the locked away books, filled to the brim with the secrets of the past and forbidden knowledge; she looked forward to excitement of the adventure to the far away lands and mysterious places, being able to see the relics of the times long gone and the remains of civilisations, remembered only by the ancient minds of the Diarches of Equestria; she adored the praise, the love, of her teacher and friends, she’d recieve at the end of the road of her adventure; but the most satisfying feeling of them all was that amazing sense of accomplishment, often accompanied by the sound of the scraping quill against the fresh scroll, as she recorded hers and her friends adventure, filling line after line with words on how many friends they’ve made, what troubles they avoided, whom did they helped, and finally -- how they solved the mystery and saved the world, once again.

Yes, Twilight wholeheartedly loved the mystery and adventure.

But the one thing she hated, was adventure without her friends.

With a that thought finished, the magical grip on the piece of the ancient tower of the Great Sunken City disappeared, as it was launched into the pursuing Saddle-Arabians, cloaked in the black robes and carrying short but still very sharp and deadly silver blades, drawn from their leather sheets.

Without skipping a beat, they put more power into their practiced gallop, simultaneously jumping forward, and then easily avoiding the crashing tower with their almost acrobatic maneuver.

‘Horse-apples!’ Twilight cursed silently, her mind already coming up with new solution for the fastly closing in problem.

Until she noticed more stallions and mares, jumping and running along the rooftops of the eldritch city, blinking in and out of view, as if they were shadows, flickering at the edges of ruins in the light of the torch.

It was then, the moment of clarity in her working mind, the realisation, the worst and at the same time the best of the possible outcomes:

‘They’re leading me into the trap,' Her eyebrows dangerously narrowed with the cold determination, 'Now is the time to spring mine,' with that, using her last reserves of the earth pony magic, the disguised Princess of Friendship zoomed out of the way of suddenly appearing foe, narrowly ducking out of the way of the glistening in the light of the sun blade, following by the immediate blast of the hard telekinetic force to the unlucky mare's body, sending the wide eyed pursuer crashing into the four assassins, that weren't ready for her, like they were for the tower.

Twilight jumped off the ground and pushed herself with the same spell into the alleyway to her right, disappearing out of the way of almost a dozen of arrows, suddenly slamming into the sandy ground below, while she gracefully landed in the alleyway, that not so coincidentally lead right to her objective.

‘This cat and mouse ends now,’ the princess thought, as she dismissed the memorized copy of the map, putting it safely into the mental box of important things for a later use.

Then, after careful zigzagging she suddenly came to a stop at the center of the town square Twilight was looking for, right under the big monolithic statue of the unknown alicorn, made form the uncommon form of obsidian, cut so perfect, its surface non distinguishable from that of an inky black glass.

But the princess in disguise had no time to take in the details of the strange, otherworldly statue.

Twilight turned around, only to immediately see almost fifty dark figures, sprinkled around the line of the empty buildings like chocolate sprinkles on her favorite dessert from the Donut Joe’s Dinner.

Some of the assassins were on the roofs, holding the bows and glinting in the light with that blasted magic-defiant silver. The ones on the ground, slowly emerged from alleys and streets, branding more of the silver weapons, that ranged from knives and short blades, to sickles and long swords that will send any magic user running.

Twilight could see their smiles, the amusement and predatory cheer, they finally caught her, and now, as if they were the predators, Saddle-Arabians began to slowly approach her, while the one with red robe, presumingly their leader, was trotting in the front of the group, giving her another victorious smile.

Oh, how much she will enjoy wiping the smiles from all of their faces.

Twilight Sparkle waited for them to get close enough for this to work and then smiled cockilly at her pursuers, slightly nodding to the ground, where her hoof was tapping fast on one particular brick under her.

Immediately, the amusement turned into confusion, and then into fear in the eyes of the leader to the Guild of Assassins, as his gaze slowly fell to the ground.

He understood that this tiny unicorn mare wasn't teleporting not because of magical fatigue, that she snaked her way to the statue not to avoid arrows, and that he missed the small glowing her horn emitted the whole way through the square.

The stallion looked up from the slightly glowing runes on the cobblestone right beneath his hooves, only to see the “unicorn” mare with the predatory smirk, repeatedly tapping hoof on the brightly shining rune, when suddenly he felt a powerful spell gathering ungodly amounts of magic into a gigantic ominous ball of pure concentrated magic, that slowly gathered out of thin air, behind the crazy mare.

“RUN!” the leader called out to his assassins, when the ball of magic suddenly came down into the same rune Twilight was tapping for all of the time they took to menacingly approach her.

The whole square suddenly exploded outwards, as the kinetic force from her tapping and Saddle-Arabians walking through the runes on the town square, that Twilight carefully multiplied and distributed through the clever use of runic magic, rushed out of the ground with a massive “BOOM”, that echoed throughout the city, while the massive surge of violet light blinded the archers on the rooftops, only then Twilight took hold of the big head of the statue and disappeared with it out of the harm's way in the just as bright flash of the long distance teleportation spell.

===

One month earlier. Canterlot palace. 8:47 in the morning.

===

Twilight was tired.

The sleepless night in the Castle Archives was spent in studying new financial laws and regulations, the Parliament of Noble Houses decided to pass under the noses of the princesses. They were strictly scrutinized by the keen eyes of one of the most knowledgeable ponies of today’s Equestria and the Diarches of the Sun and Moon all day and then night, with small breaks for tea and food, because of course there would be a time limit for princesses to dismiss or pass the documents before they will be officially passed. The nobles almost succeeded in their trickery, by filling up the schedules of day and night courts with their pointless and staged problems, pushing the attention of the princesses away from the review of the legal documents, and heavily bribing staff in the Archives.

Until some of the them, alongside with few of the noble houses, leaded by non-other than Fancy Pants, strolled into the day court with massive stack of documents and reports, detailing the investigation on the whole affaire.

Many unicorns were arrested that day, many reputations were ruine, and almost all of them were stripped of their noble titles and their wealth added into the Royal Treasury. This way, in one big swoop, that apparently was organized in secret by Princess Luna, the capital, and by the same margin the country, was cleaned off the filth from the ranks of the now noble class.

But apparently, Night Princess timed the whole thing poorly, and with the Hearts and Hooves coming up this week, the Diarchy couldn’t reach for help to Cadence and Shining Armor. That’s why there were only three of them in the archives, rustling through the legal documents and witness reports.

Though right now most of details to the investigation were blurry and hazy for a sleep deprived Princess of Friendship, while the echoes of the cleverly worded lines of text still filled head like a catchy song you’re sick of hearing.

Maybe that's why she missed the turn to the guest room wing, and turned to the right instead of left a couple of times, or even missed some of the turns sleepwalking, but her journey through the palace was cut short, when she finally bumped her sturdy alicorn head at the wall in a dead end corridor.

"Ow."

A pause...

“That’s odd...” the tired princess muttered, her eyes taking in the smallest of details of the hallway, even in her tired state.

The dust, the old banners and tapestry of the time period in Equestria's history, when it was a Solar Empire, that ended with Peace Treaty of Griffinstone almost two hundred years ago…

Conclusion? This part of the castle was abandoned for a very long time.

At this point Twilight’s drowsiness went away with a blink of her violet eyes, replaced by curiosity, while her mind went into the focused state and a small smile lightly tugged at her lips.

She could smell it in the air…

“The mystery is just around the corner,” the said with joy in her voice and a sparkle (her-hee) in her tired, yet full of life eyes.

She took a good look around her once more, the early morning sun was shining through the dirty windows, but there, in the last moment of the dawn, the rays of the day break sun refracted strangely, as if the glass was slightly thicker than it actually.

That, made Twilight smile outright.

The brief flash of her horn, charged with diagnostic spell, confirmed her suspicions, it was a notice-me-not illusion spell, crafted to fool the ponies on the outside of the castle walls, and, most importantly, it was cast by an alicorn.

That big discovery made Twilight giggle like a school filly and do a little dance, shuffling excitedly on the spot.

Right until she began choking on the dust, “Pfe~ cough-cough, right, cough, dust,” she choked out and casted a small cleaning spell on her.

“That’s better,” she said to herself, “Now… Let’s see... Here!” she light her horn again, casting a complicated spell in front of her eyes. From perspective of the onlooker it resembled a simple clear reading glasses, but they also allowed her to see through illusions.

“Oh… My.. GOSH!” she exclaimed suddenly, as the wall she bumped her head into slowly, almost reluctantly morphed into a tall doorway, covered by a shimmering force field of the familiar golden color, which if was not the dead give away on who made it, then the sheer power behind this masterfully crafted barrier certainly did.

“It’s unreal!” Twilight could not believe her eyes, “It’s perfect, in every possible way! The structure, the power, the detail! I couldn’t even tell the difference between this magical barrier and the simple wall!” small alicorn was in awe at the display of the work of her teacher.

She found a new, no, an old forgotten mystery, “But what’s behind the barrier? Why is it here?” this two questions only served to fuel her curiosity.

'No! I will not disturb Celestia's privacy!' Twilight turned away from the doorway.

'But... what if..? No!'

She continued to fight with herself, walking up and down the hallway, her walks slowly gravitating towards the barrier while Twilight argued with herself, until she bumped into it again.

Princess of Friendship looked at the force field, pouring all the disgruntlement and resentment she could into her gaze.

The barrier ignored her.

Her face slowly morphed into one of sheepishness, and remorse, "I'm sorry, Princess," she muttered under her breath.

Biting her lower lip, Twilight light her horn again, beginning the slow process of unlocking the powerful barrier, putting almost all of her concentration into the task, while the small part of her mind stilll wondered.

‘What secrets Princess Celestia hides behind this impenetrable wall of illusions and barriers, deep inside the castle, in the section, that hasn’t been visited for hundreds of years?’ this question and many others were swimming inside Twilight’s mind, nagging her, pushing her towards the unknown.

This fateful morning, on the fifth day of the second month of 1012, Twilight Sparkle, the Princess of Friendship, took the first step into her adventure.

This morning she uncovered a terrible mystery, long time forgotten.

...

This morning, in the south, buried deep in the sands of time, something stirred.

Author's Note

This struck me in the head like a pile of bricks. So I decided to write this.
Hope you liked this chapter)