This early in the morning the palace corridors were all but deserted. The only faces Twilight passed in the corridors were those of the stern Night Guard quietly attending to their posts.
When she was younger she had found their dark features and sharp teeth off-putting, but time and her affinity for getting lost in the castle had made her appreciate them. It also helped that in her first week living at the castle Captain Darkwing had shown her the best way to the castle archives.
Nodding to the two thestrals at the entrance to the corridor, Twilight headed towards the door to Princess Luna's chambers.
For all that her teacher was seen as a detached and reserved figure to the public at large, Twilight knew just how much she cared about every pony around her. It was one of the reasons she so rarely slept.
Raising a hoof to knock on the door Twilight hesitated. Maybe she shouldn’t disturb her mentor. The princess was very busy after all.
She steeled herself. This was important. This lost princess was due back tomorrow and any disruptions to the negotiations with the Griffon ambassador could be disastrous. Besides Luna had an open door policy for a reason, even if no pony else seemed to know about it. She wanted to hear Twilights concerns.
"You going to knock or not kid?"
Glaring back at the guard smirking behind her, Twilight took a deep breath, then tuned around and knocked on the door.
It swung open.
The guard snickered.
Of course the open door policy was literal. Twilight kicked herself for forgetting. Again.
Mentally cataloguing all the ways an open door was impractical for royalty, Twilight stepped into the room.
Luna sat on a large white cushion in the centre of the room surrounded by a number of other cushions in varying shapes, sizes and colours. Her eyes were closed in rapt concentration whilst a small frown furrowed between her eyebrows.
Crossing the room Twilight picked her favourite of the cushions, a particularly fluffy one in cerulean, and pulled it closer to the meditating alicorn waiting patiently. To pass the time she began to catalogue the different cushions.
They ranged from all colours of the rainbow everything from red to green. They were every shape and size as well. Some looked as if they could easily accommodate a yak or minotaur whilst others were small enough only for a small foal to sit in. She looked back at a patched orange cushion in fondness.
Every size shape and colour was there, except one. With surprise Twilight noted there was not a single yellow cushion in the twenty two cushions that lay dotted around the room.
Twenty two cushions and not a single one in a primary colour. It seemed strange. Luna had never thrown away a single cushion away in all the years Twilight had studied under her. If anything Luna had added to them. Why wouldn’t there be a yellow cushion? Some of the cushions didn’t look like they had ever been sat in.
Twilight suddenly realised that she had never seen this room filled. Not once. Suddenly that open door made a lot more sense.
Shifting uncomfortably on her cushion she moved to stand.
The glow of Luna's horn faded and her eyes opened.
Glancing over at the noise her smiled widened, only to become more strained when she noticed Twilight moving to leave.
"I hope I didn’t keep you Twilight Sparkle. Nightmares in the young around Trottingham have been much more common as of late."
"No, of course not Princess Luna. I just wanted to ask you...no it’s silly really."
Princess Luna's smile widened almost predatorily. "What is it Twilight? It's not a colt is it?"
"No, of course not!" Twilight spluttered.
"That IS a shame; I know Chrysalis is enjoying facilitating the connection between your brother and Princess Cadenza."
"But...but I thought that was a diplomatic mission!"
Luna smirked. "That's what THEY think."
"But the changelings, the international relations!" She paused to consider all the possible ramifications of that statement. "Actually I don’t want to know." Pushing away the unwanted images of the diplomatic relations she'd walked in on the last time Chrysalis had visited Canterlot she continued on. "Anyway this is about something else, something more important."
Luna's jovial grin faded, replaced by a serious gaze. "I am listening Twilight."
"I was looking into historical relations between Griffonia and Equestria when I found something." She hesitated.
"Go on Twilight."
"A thousand years ago there was a massive political upheaval which led to a brutal war between Equestria and Griffonia lasting ten years."
"I am aware Twilight. I was there."
Luna's voice sounded strained.
For a moment Twilight regretted bringing the war up. There was a very good reason Luna and the griffons didn't get along. She forced herself to push the worries aside. This was important. The past could hardly do any more damage than it already had.
"Oh right. Anyway I was looking back into the causes to find something that might help in the diplomatic talks when I found something strange. All the Griffonia communications kept referencing a lost princess but the king of the time only had two sons and they referenced you by an entirely different term."
Excitement filling her voice Twilight looked over hoping her mentor was sharing in her enthusiasm. Luna's face was stone.
"Umm, anyway that made me look deeper. And that’s when I found all these other references to a Sun princess who used to rule Equestria."
She looked back at her teacher expectantly. She met a wall of silence.
"Then I thought what if there's something in the old lore section so I looked and then in Predictions and Prophecies by Clairvoyant Gaze I found it."
Pulling out a somewhat crumpled scroll she held it out to the Princess who observed it as if it were a hissing serpent.
Her teacher having not taken it Twilight pulled the scroll back towards her, clearing her throat. Unrolling the parchment she began to read.
"The lost princess of the Sun. Fallen defeating the terrible Nightmare, she saved all Equestria by binding herself into the Sun along with the Nightmare.
On the longest day of the thousandth year she shall return draped in the glory of the last rays of sunset. And the Sun shall never set on her reign."
Looking up from the parchment back to her mentor she saw Princess Luna swallowing harshly, her impassive façade cracked. Her voice however was calm and measured. Too measured.
"Thank-you for bringing this to my attention Twilight Sparkle. I shall be sure to give this all the consideration it requires."
Plucking the scroll from Twilight's grasp she turned away to file the scroll in a nearby cabinet. The sound of the key turning in the lock was clear. This conversation was over.
Twilight watched in desperation as the answers slipped further from her grasp. Unanswered questions burned on the tip of her tongue, fighting to escape. It was a losing battle.
"But who was she?" she burst out. "What happened to her? Why was it so important to the Griffons?"
Princess Luna turned away from the cabinet with a sigh. Sitting heavily back down onto the cushion, she fixed Twilight with a look of exhausted resignation.
"It is just as the scroll says Twilight Sparkle. She was a princess, like me, a long time ago. She controlled the sun and we ruled Equestria together, until she was lost to the Nightmare."
"Is that why there's that empty throne in the throne room Blueblood keeps trying to sit on?"
"Yes."
"And why you always call yourself the Steward of the sun rather than its mistress."
"Yes."
"And why…"
"Yes!" Luna shouted in exasperation before quickly regaining her composure.
"But what happened?" Twilight asked softly.
"There was an...incident. Celestia used the elements to defeat the Nightmare at great personal cost. That is all I wish to say on the matter."
"That was her name? Celestia?"
Luna nodded jerkily.
"It's beautiful."
Luna smiled, eyes glistening. "I always thought so."