"Thank-you so much for coming so swiftly on such short notice, Twilight." Celestia smiled, leaning down to hug the younger mare.
Twilight giggled. "Well your letter did say 'as fast as convenient'. So what's the problem? Diplomacy troubles? Another Tartarus breakout? Discord?"
"Oh gracious, no, Twilight," Celestia smiled, and began to lead her out of the throne room. "This is more a sort of internal affair. Luna and I have been... discussing a lot in recent months. This concerns you, and Cadance, and we both feel that now is the time to bring something to your attentions."
"Oh, is Cadance here too?" Twilight's step grew springier as she followed her old mentor.
"Yes, Luna is entertaining her and little Flurry Heart in the private lounge."
Celestia looked back at her ex-pupil, took in her expression, and gave a soft laugh. "Oh Twilight, you're not in trouble! If anything, this is a positive conundrum."
Twilight blinked, pausing in her stride for a fraction of a second. Then she nodded, and the two alicorns walked on in silence. As they finally approached the door to the Princesses' personal lounge, a faint murmur of voices could be heard. None of the words were clear, and Twilight had long suspected that there was some sort of subtle obscuring enchantment on the door. It discouraged casual eavesdroppers, at least.
From the tone of the voice, Luna was regaling Cadance with some ancient tale. There was the odd sharp cry which might have been Flurry Heart's laughter. Twilight looked up at Celestia, who nodded, before twisting the door handle in her magic and entering the room.
Cadance was reclining on a couch, her daughter cradled between her forehooves. Flurry was wriggling and giggling, and both of the pink alicorns were looking at Luna, who was standing on the arm of a second couch in a dramatic pose. One of her forelegs was raised, her chest was pushed out, her wings were flared, and she was staring up intently with her ears confidently pricked.
"It was on that day that the world no longer knew fear from the name Noodle Incident, and he remains locked in the bowels of Tartarus to this very day!"
Cadance applauded using Flurry Heart's hooves. Luna's ears twitched towards the door, and she turned her head to see Twilight and Celestia. She lowered her foreleg and hopped down from the couch arm with a dignified grace.
"Unless, of course, my dear sister decided to release him for one of her reformation projects in the interim?"
The oldest mare in the room laughed, shutting the door behind her with a quiet click of the latch.
"Do not worry, Luna, that is one particular villain I would prefer to never see again. Now, we're all here. Everypony, please take a seat."
Cadance sat up on the couch, scooching over and patting the cushions for Twilight. The two alicorns shared a brief hug and a coo over the baby. Luna reclined on the furniture she had recently been using as a stage, and Celestia took up a third, larger couch all to herself.
"So by now, you're probably wondering why we summoned you-" Celestia began, but Luna waved a hoof at her to stop.
"Celestia, you are using your headmistress voice again," Luna flicked her head and sent her mane rippling. "May I take the lead this time?"
When Celestia nodded, the dark princess smiled. "Excellent. Now, my young friends, this is a matter concerning who and what we are. That is, the five of us in this room. Or it might be more accurate to say the three of us, and the two of you."
As she spoke, Luna gently took Flurry Heart in her magic and brought the foal close to her face. She nuzzled the filly with an indulgent smile, and then sent the foal back to her mother.
Twilight tilted her head. "I don't understand, we're all alicorns, aren't we?"
"Are we?" Luna shared a sad smile with her sister. "You see, dear child, you and Cadance were not born alicorns. Therein lies the start of our problem. You earned your powers and your titles through bringing about new magic, and ascended from mere mortals to what you are now. However, you are still mortal. You will have longer lives than most but you will still age and die. Celestia and I, and now young Flurry Heart, we will not. When Flurry grows up, when she assumes her place in the world, she will become like us - ageless."
Twilight and Cadance glanced at each other, and then down at the little foal who was gumming at Cadance's left shoe. Cadance swallowed. "So... Flurry is going to live forever? I won't say I'm not relieved. I think every parent probably wants a guarantee that they won't outlive their children. I... Why is that a problem?"
"Oh, no, Flurry's situation is not the problem. In fact it is a blessing! No, no, our problem is you two. You two and your lack of immortality. Celestia and I think we may have a way to ascend you further, to make you like us."
"You mean, we wouldn't die?" Cadance's eyes darted between the sisters of the Day and Night. They nodded, and Celestia gave a small cough. The white alicorn's smile turned grave.
"Of course, this is not a decision to be made lightly. The method we think we have... it may not work, it is only theoretical at this point. If it does work... you will have the rest of time to contend with. I reccommend that you take some time to think about this. Do not rush into it. Take as long as you need - weeks, months, years even. Talk it over with your friends and family. Ask us whatever you want to know."
"Why do you want to make us like you?" Cadance questioned, almost immediately.
The sisters shared a solemn look. Luna spoke. "Partly because we think that Equestria will be that much richer for Love and Friendship to be embodied forever, and partly because we are selfish creatures who want more company over the eons."
"I love you both like my own foals, Cadance, Twilight," Celestia continued from Luna's words. "I want to see what both of you would become. This will not be our choice, because we are not unbiased. You do not need to justify any of your reasonings to us, and you may back out at any time before the further ascension even if you initially said yes."
"Wait," Twilight rubbed her hooves together. "You said you were born as alicorns, like Flurry. Is, I mean, um, I mean, your parents. Were they, erm, alicorns too? Like Cadance and I? Or just one of them? Or?"
"Indeed, Twilight. Our parents were ascended alicorns. We believe that they were the first," Luna's eyes drifted upwards, as if remembering the past. "They are well known in history, though knowledge of their transformations and their parenthood of alicorn foals was scrubbed from most known history."
"What? Why? Who were they?"
"They did not want our rule questioned by ties to the blood of common ponies. We were brought up within a small, peaceful community, away from the troubles of the world. Our parents had grown up in a world before Equestria, you see, before Hearthswarming. They had lived through the onslaught of the Windigoes. When they ascended, it was taken as a sign that the unity between the tribes was true. The actual country wasn't founded officially until I was five years old.
The leaders of the tribal factions were among the few that knew of us, and when we were born it was decided that we were to be instated as the new rulers of the new society when we were of age. A pair of ponies who embodied all three tribes in one. So we were introduced upon our adulthoods to the world, as harmonic beings from a dimension made of magic. The leaders bowed to us, and then so did their ponies. Soon after taking the thrones, we discovered our twin abilities in moving the lights of the sky, and our positions were sealed."
"Wow. so your parents were just... ordinary ponies? What did they do to ascend? Both of them?"
Celestia gave a small chuckle. "Not quite ordinary, Twilight. In their day, I suppose they were the Alicorns of Friendship. They didn't get titles, everypony was too confused. All three of them ascended together."
"Three?" Both Twilight and Cadance tilted their heads in synchronised confusion.
Luna gave an amused snort. "Oh, now let us stop being so cryptic for once. You two of all ponies are worthy of our secrets. Children, our parents were Clover the Clever, Smart Cookie, and Private Pansy. The creation of the Fire of Friendship also ignited their full potential and ascended them that day in the cave."
Twilight's eye began to twitch. "Clo- what? Pans-Smar-? Your? Huh?"
Cadance's ears had pricked up. "Smart Cookie was your father? Are you half-sisters? I didn't even know any of the founders had relationships with each other."
"Clover the Clever, Smart Cookie and Private Pansy began a herd marriage during the formation of Equestria proper," recited Tilight, instinctively. "They went on to have four children in total. Creek the Crafty was their eldest, and daughter of Clover. She went on to be a well-renowned earth-pony scholar who helped Starswirl the Bearded with a lot of theoretical magical discoveries. His notes about her say that while he had at first been skeptical when she began to criticize a few of his methods, he would have taken her as one of his last apprentices had she been a unicorn like her mother.
Pansy then produced twin sons, both pegasi. Tough Cookie joined the early EUP and while he never made Captain status he was always relied on for advice and served as second-in-command for thirty-eight years under three different Captains. Heart's Ease was the younger twin and gained a reputation for being a mare's stallion in his youth. He later settled down with one of Princess Platinum's daughters and had many foals who would go on to found some of the earliest noble houses.
Finally, Sweetgrass Star was Clover's second foal and the youngest the herd had. She was a unicorn who joined the military after her brother and became one of the military doctors. She invented a number of minor healing spells that are still used today but never had the magical genius to study under Starswirl."
Twilight blinked. "Wait, you two had siblings?"
"Ah, do you remember when Swee was born, Celestia? She was so tiny!"
"I remember all of you being born, Luna. The boys were definitely the tiniest."
"Hah, and they grew up to be the tallest! Excepting you, perhaps. I... wonder what they all would have thought about what has happened overe all of these years."
Twilight whimpered slightly, breaking the elder alicorns from their reverie. "B-but? All my books have lied?"
Cadance patted her on the back between her wings. "This is... an interesting new perspective. So it was only you two who were born with horn and wings?"
"Yes. While we only have a sampling of two, ah, now three, it seems that only the first child of an ascended alicorn will be a nascent one."
Cadance's eyes widened. "So... any future foals I might have... they would be mortal?"
A nod in response. Cadance looked down at her daughter, biting her lip.
"So if I want to have foals... my first foal will be an alicorn? Oh goodness," Twilight chewed on her hoof. "Oh goodness."
She fixed Celestia with a panicked stare. "What about you? I mean, have either of you? Er. Had foals?"
"I have not," Celestia looked away for a second, choosing her words. "It may be that I can not."
"Oh."
"I, on the other hoof, have not attempted to bring about motherhood," Luna sniffed and gave a little shudder. "I like foals, and I like the idea of them, but for some reason the thought of growing one inside me fills me with an inexplicable dread. It has since I first learned the full mechanics of making offspring. I am content to consider our people as my surrogate."
"Ah," Twilight squirmed. "I'm sorry, I didn't mean to bring up anything weird or-"
"Twilight, relax. This is the sort of thing we were expecting you to ask. If you ever want foals - consider that ascending to immortality may take that option away from you. Again, you have years to consider your answer. Your whole lifetime, should you wish it."
The room lapsed into silence, and all of the mares looked at Flurry Heart.
Cadance was first to break the quiet. "If you don't mind, I would like to go home and talk to Shining about this, and send you a list of questions once I have had the time to think on this more."
Celestia slid off of her couch and stood up. She stretched her large, white wings out and walked to Cadance with delicate steps.
"That sounds like an excellent idea, Cadance. Writing down your thoughts can have a wondrous effect on untangling them."
The tall mare leaned down to peck Flurry on the forehead beside the horn, and then wrapped Cadance in a one-legged hug.
"Take care, Princess Cadance," Celestia turned her head to look at her ex-student. "What about you, Twilight?"
The purple alicorn started, and looked at Celestia for a few long seconds. "Oh, um. I might do the same. I mean, go home and talk to Spike and my friends. Not Shining. Maybe Shining?" Twilight glanced at Cadance. "I'll send a letter? Then writing questions for your letter. Then... thinking."
"A most promising plan, dear ones, we will be looking forward to your missives," Luna waved from her couch. "Forgive me if I do not arise to send you off, but this couch is comfortable, Celestia gives better hugs than I, and I am overdue a nap."
Luna promptly set her head on her hooves and closed her eyes. Celestia embraced Twilight briefly. As Twilight left the room, she could see the white alicorn beginning to levitate a blanket over her younger sister with an indulgent smile. There were still questions spinning about in her head, but first she was going to make a list. Cadance was waiting for her outside the door, her daughter perched and burbling on her back. The two younger alicorns set off down the corridors together in companionable silence.
Before they opened the palace doors, Cadance held up a hoof and turned to her sister-in-law with a smile. "I'm going to fly back to the Empire now, Twilight, any messages for Shining?"
"Tell him he's a dork and he should visit sometime," Twilight smiled back. "Do you have any idea what you're going to do?"
"I think... I want a family first, Twilight. But I also don't want to see them pass on while I never age. If we knew for sure if I could have foals or not as a full alicorn, and what they would be... I don't know. If I ever do decide to go for it... I don't think it will be for a long time. That's all I can say right now. What about you?"
"No idea. There are a lot of things to consider."
The mares nodded together, and Cadance pushed open the doors. "See you soon, Twilight."
"See you soon, Cadance."
The pink alicorn spread her wings and flew away.