Magnificent in her full royal regalia, gaze imperious, rainbow mane blowing in an ethereal wind, Princess Celestia Sola Invicta, the Senior Ruling Princess of the continent-spanning Realm of Equestria, reappeared on the white Green Mountain marble plinth that was her currently active teleport stage. The two Day Guard stationed there saluted, and were respectfully silent.
There were times when Celestia loved to banter with her personal guards. This was not one of them. Her guards sensed this, and deliberately avoided doing or saying anything to draw her attention.
Saying nothing herself, the big white Alicorn mare strode past her guards, and closed the double doors behind her.
The moment she was alone in her bedchamber, Celestia staggered over to her desk and slumped in her chair, her expression stricken, her breathing ragged. Her eyes fixed on a picture of her Most Faithful Student.
I almost lost you, Twilight, she thought, about as close to terrified as she ever got. Sweet Mother, you almost fell into Nightmare.
She laughed mirthlessly. Now that would be a fine joke, would it not? To get back Luna at last, and less than a year and a half later lose Twilight -- my hope for the future, my friend, the daughter of my heart. And right after she defeated Discord! That would have been ironic -- quite horribly ironic.
She found that she was trembling.
Delayed reaction, she knew. My adrenal rush has worn off, this is my body paying for that icy calm I felt when I was actually bringing Twilight back from the brink of madness, finding the exactly proper words to use on her and her friends, being a machine instead of a mare, because a mare might have made a mistake, and a mistake then could have been fatal to Twilight's sanity. I could override this fear I now feel, but it's best not to do so, better to go with the instincts of my flesh-form.
She was an expert in being a Pony, having spent over twenty-five centuries as Celestia Sola Invicta, in these recent Ages of the World; and thirty as Epona Amaterasu the Sun Mare, in the Age of Creation, many millennia earlier. So she had some confidence in her own judgement regarding the demands of her immortal housing.
I thought I was ready for Discord's return. I really did. I'd been preparing for it for fifteen hundred years, after all. But when he was there, really there, brilliant and mocking and sinister as always, yet with that playful tone that was so very much Dissy, my poor sweet lost love Dissy ... I couldn't fight him, even though I'd been able to fight him before, because I'd forgotten what it was like to see him move, hear him speak, hope against hope that I had him back ... I couldn't evade or outwit him, could barely think straight. My mind was too full of choked rage, ancient pain, of old, never-forgotten desire ...
Fool! she berated herself. Immortal, besotted, fool! You hesitated, froze ... and he had you, in every sense of the word save the one you most disgracefully wanted! Your self-indulgent, lecherous sentiment nearly condemned everypony to countless centuries of suffering beneath Discord's mad misrule!
What use the most magnificent of minds, in the service of a fool?
So I was captive, and Luna alone had some measure of freedom, because she had the wit to pretend that she had already been unbalanced by him -- and Discord was always a sloppy thinker, even back when he was Dissy; even our own Beloved Teacher never could cure him of that failing. And so the full weight of Discord's maddening influence fell upon Twilight Sparkle and her friends, and mostly upon Twilight Sparkle. And damaged her, though I did not see this at first.
She turned and regarded herself in her mirror. In her sungold tiara, peytral and sabatons, she looked beautiful and regal, and she knew it. As Fusion, I crafted the Alicorn form for equine hyperdominance. I could say almost anything, do almost anything, and most Ponies would still admire me, respect me, follow me with smiles on their faces. Not because they're stupid or weak -- they're not. They're smart and strong, and brave without the crutch of being super-powerful and almost impossible to kill, as well I know myself to be when I counterfeit their shining courage -- but simply because a being beyond them in both power and knowledge took advantage of their sociobiology to install herself at the top of their hierarchy. I could be a trollop or a tyrant -- some of my alternate selves have been either or both -- obviously unworthy of their respect, and yet many Ponies would still follow me, both due to my hyperdominance, and due to their own virtues. The Ponies are a loving and loyal species.
And what do I do with that loyalty, with the trust they've placed in me? Why, I hold back against Discord, because of what once was and never can again be between us, so that he captures me and torments my loyal little Ponies. Not me, of course -- he has never directly harmed me, or my Sister, because he loves us, in his own sick way -- but my Ponies: they're just toys to him.
And to me? She regarded herself in disgust. Look at me! All dressed up to play the Princess Game, just as I did when I was a filly, only now I have better props, a bigger play-room, and real Ponies with whom to play. And if I make a mistake -- if there's an invasion or raid or plague or famine -- why, it is my loyal little Ponies who suffer and die, like good little toys, whilst I lounge in hedonistic splendor.
Am I really that much better than Discord? At least he never demanded that the Ponies love him.
She buried her head between her forehooves. She wanted to cry at the mess she had made of things, but she couldn't. It would do no good -- and besides, she was much too numb for tears.
She'd screwed up. And Twilight Sparkle had saved her, once more, from the effects of her own errors, just as she had done so over a year ago by bringing Luna back to her. Only this time Twilight hadn't quite saved herself, because just a week later she was committing warlockry on her friends and neighbors, and all because Twilight had thought Celestia cared so much for Friendship Reports from her former student that Twilight needs must create problems to solve!
Celestia had been terrified -- not so much of the damage Twilight's geas might do, though if Celestia hadn't dispelled the enchantment, somepony might have been seriously injured in the brawl over that little doll -- as of the implications that Twilight Sparkle was doing this at all. She remembered how Luna had been hurt by King Sombra, and yet fought by her own side to triumph over the Night Stallion Imperator, only to spiral into madness and Nightmare within eleven years.
I lost Luna to my own laziness and squeamishness, she thought. I couldn't be bothered to talk to her about what was wrong -- it was too emotionally uncomfortable for me -- and so she suffered a thousand years of torment for my own weakness. If not for Twilight Sparkle, things would have turned out far worse. Shall I now lose Twilight to the same causes? She looked in the mirror, seeing her own face, the mask of an emotional coward. No -- but what can I do to make up for my follies?
More than one of my special students have gone mad. I push them too hard, beyond their normal equine limits, because I'm trying to attune them to their Cosmic Selves, and I can't even let them know that's what I'm doing. They want to please me, and they try too hard, and they are lost.
Starlight Glimmer, twisting Starswirl's unfinished enchantment into that terrible Spell of Sameness. Sunset Shimmer, insisting on an Ascension which she did not grasp was at that point impossible, and then fleeing me into another dimension. Dawn Starfall, deciding that she was already the Chosen One, and thus above ordinary law and morality. And many others, whose breakdowns were less dramatic and complete, but who nevertheless turned away from the path on which I strove to set them.
I had to push them hard, I have to if I'm to get them to transcend normal Pony limitations, so that -- when the storm that I have sensed gathering for over a thousand years finally strikes, I will not have to be Ponykind's only protector. It's hard on them, and hard on myself, because I inevitably wind up loving them. She laughed sardonically to herself at that excuse, glaring at her own reflection. As if the pain to me somehow justifies the pain to those innocents who put their trust in me! Truly, I can be corrupt, and clever in my hypocrisy!
It was of course not true that all, or even most of her students broke under the pressure. Had that been the case, Celestia would have long ago given up trying to teach them. The vast majority of her students actually benefited by her teachings: of the majority of those who became her special students, few actually broke under the strain. Most just went as far as she could take them, then more or less gracefully accepted their limitations, and left her personal tutelage to pursue more normal courses of study.
She only accepted the brightest and hardest-working students into the Academy; exceptional Unicorns who also had a special spark of curiosity and determination. Students who graduated the Academy went on to become the most skilled scholars and mages, taking their places among the Equestrian elite. Her special students generally became famous for their achievements, their names and deeds inscribed in flaming letters in the annals of Equestria.
But some went mad. And of her special students, it was the most gifted who were likely to go bad in the most spectacular ways. After centuries of trying, Celestia had begun to despair that she would ever find any of the New Alicorns she hoped to bring forth from Ponykind.
Then, there came Twilight Sparkle.
She was special. She had been obviously brilliant from her performance in elementary school. Celestia had suspected that her channels were blocked; her talent so vast that it could not emerge under normal stimulation. Celestia set her the Dragon's Egg problem to see how she might respond to an impossible task, to see if under the pressure her magic might begin to manifest. She did not expect anything much to happen, just a thaumic discharge by which Celestia might, analyzing its signature, understand the nature of Twilight's talent.
Twilight hatched the egg.
And in that vast flare of magical energy, Celestia knew that a fetal Cosmic Concept was stirring, kicking with a force as yet weak and uncertain -- thought terribly powerful by mundane standards -- reaching out to the mortal world through its Avatar, the filly Twilight Sparkle.
And she sensed something else. Twilight Sparkle had been Dusk Skyshine -- the one Pony who might be able to reach out to Luna and bring her out of her madness. For the first time in centuries, Celestia began to let herself feel real hope for her Sister.
Celestia was of course curious about the Sonic Rainboom that had been widely reported from the direction of Cloudsdale. She soon discovered that Rainbow Dash -- then only eight years old -- who had done this. And she recognized her as well. Dash Firehooves, Dusk's best friend, and one who had been very dear to both Sundreamer and Moondreamer.
Reports came in of other young Ponies who were manifesting unusual abilities.
This was no coincidence. She knew what had happened. Her attempt to bring about the birth of new Concepts in Equestria had triggered the psychic equivalent of a phase transition; similar though smaller than that which had happened when the Universe had begun. Potentiality had coalesced around Celestia and her Sister, and a whole new generation of Cosmic Concepts were being born -- as always, in response to the needs of the Universe.
In a sense, Celestia and Luna were their mothers, though it was an imperfect analogy, as reproduction was very different on the Cosmic Level. Had they been the mothers, the Ponies of Equestria would have been their mates, who brought about this happy miracle.
In one way, this was literally true. Celestia was certain that Twilight's matrilineage could be traced back to Luna and Prince Pathfinder Metallic, around twenty-four centuries past; and her patrilineage to Luna and the astronomer Night-Watcher, thirteen centuries ago. This fact was less significant than it might seem: though the Sisters each took only one or two lovers a century, and only occasionally chose to have children by them, the twenty-five centuries Celestia and fifteen centuries Luna had spent incarnate in their forms on Earth meant that they were ancestral to most of the Ponies in modern Equestria
In another sense it was very significant. Celestia had spent the last thousand years quietly encouraging matches between certain lineages, the better to concentrate and reconcentrate the heritage of the Royal Pony Sisters, without establishing numerous new Princely Houses. One Clan within which Celestia had spent longest at this labor were the Lights -- the Clan to which belonged Starlight Glimmer, Dawn Starfall, Sunset Shimmer -- and Twilight Sparkle.
It was not, though, owing to any such literal consanguinity that Celestia came to love Twilight Sparkle as if she were her own daughter.
Twilight was hardly unique among the Ponies at the Academy in being intelligent, even brilliant. All the young Ponies there were of exceptional intellect; and that went doubly for Celestia's special students. But it was not for Twilight's intelligence alone that Celestia so greatly valued her.
Twilight was smart, but Twilight was also sweet, her sweetness relieved from cloying perfection by a driving ambition and a certain wry sarcasm that very much reminded Celestia of her Sister and herself when they had been young. And Twilight was good: she believed in and practiced the highest ideals of Equestria: a moral philosophy which Celestia herself had carefully-inculcated in that civilization. She was of the most honorable type of the Canterlot gentry, a scholar-mage of an old military family, loyal to the Realm with all her heart and soul. Celestia could not imagine someone better-suited to be her new Magic.
Then Twilight passed her first great test. On the longest day of the thousandth year since her banishment, what Celestia had long known would happen had happened: Nightmare Moon had returned. And Twilight Sparkle had gone to Ponyville, to the town Celestia had planted under the eaves of the Everfree Forest, on the most direct route from Canterlot to what had been the City Foreverfree, the once-great old capital of Equestria, now rubble loomed over by the ruins of the old Castle -- had gone to Ponyville, on Celestia's command, to supervise the Equestriad Summer Sun Celebration, and to make friends.
Celestia knew what would happen when she told Twilight to go to Ponyville to make friends. The great working she had long ago laid, a webwork of magic akin to though vastly simpler and weaker than the power of the Paradise Entity, was a temporal net of destiny which would draw together the five strongest other candidate Element Bearers to her candidate Magic. Another strand of that web would draw Nightmare Moon -- the prison which contained her the soul of her poor Sister -- to the center to meet the Element Bearers at precisely the right moment. When Nightmare Moon had suspected that Celestia had left some long-laid trap for her, she did not know how right she had been -- only at the point she suspected this, it was already too late, the Moon Princess was already caught firmly within the trap's jaws.
But Celestia's temporal magic could only trap her misguided Sister. It was her Magic, and the other five Elements Magic would attract, who would bear the burden of walking into the same trap and confronting the Nightmare.
On her own initiative -- which, owing to the conditions of Celestia's magic, were the only way that the deed could be done -- Twilight Sparkle had led the five friends she had made, the five candidate Element Bearers, deep into the monster-haunted forest, beneath the unnatural night of that summer morning, to brave the traps of the Moon Princess and confront the Nightmare at the forest's heart. Twilight and her friends had attuned to the Elements, and used the Rainbow against Nightmare Moon, and ...
... and ... and ...
Even now, Celestia still shivered in happiness at the the wonder of it all ...
... Twilight had liberated Luna from the Nightmare.
Celestia had her Sister back again, mostly sane and whole, though it took her some months to come all the way back to her former glory and power, and she was still a bit emotionally-subdued after a thousand years of horrible exile, thrall to the Night Shadows. But it was really Luna. She was really there. After a millennium of loneliness, Celestia no longer had to rule on her own. Once again, her Sister was with her.
And it was all thanks to Twilight Sparkle.
Celestia had always loved and valued Twilight Sparkle. Now, if it were at all possible, she valued her even more.
For more than a year, Twilight had dwelt in Ponyville, acting officially as librarian, but in truth as commander of the Champions she had assembled, guarding the southern Vale of Avalon against the threats which might emerge from the Everfree and White Tails, lashed on by the same Night Shadows who had tormented Luna. Twilight's performance had been exemplary; she had overcome every challenge the hell-forest had thrown at her. Perhaps more importantly, Twilight had learned how to get along with other Ponies, on more than a superficial level.
Twilight Sparkle learned how to make friends.
This was vital, and not merely because Magic was by its very nature based upon the links forged by quantum entanglement, links which when proliferating between Ponies were generally the indication of a strongly-linked destiny, such as existed between the Element Bearers. It was also vital because of the very great danger of Nightmare should an Alicorn -- which was what Celestia hoped Twilight might become in time -- go Lone-Mad. The danger grew greater the more powerful the mage and -- Celestia knew now that this was due to the increasing numbers of Night Shadows seeping into this Universe -- in recent centuries, it had become easier and easier for a mage to slip into the Nightmare state.
Friends could help keep Twilight from Nightmare. They had already helped get her further toward Ascension than any of Celestia's previous students had managed before.
Then, Discord had escaped. Then, Celestia had thrown Twilight and the other Champions against the Draconequus. Then, after nearly succumbing to his unbalancing, Twilight had recovered, with the help of the old Friendship Reports Luna had sent her, and used the Elements to seal Celestia's poor mad lost love once again in stone. And Celestia had publicly decorated her Champions, honoring all of them, and most of all Twilight Sparkle, her Magic, her Most Faithful Former Student -- the secret daughter of her heart. And everything again seemed right with the world.
And then, a week and a half later, Twilight had gone mad. And Celestia had -- just barely -- been able to get there in time to save her, before Twilight had gone too far down the path of Lone-Madness, or wreaked some harm on innocents that would have burned in her conscience for years to come, blighting the dreams and sapping the self-confidence of her Magic, her greatest Student, her dear daughter.
Spike, Celestia thought with gratitude. You helped save her. You saw what was going on, realized it was a descent into madness, and you wrote to me. Without you ... She did not even want to think of a world without Twilight Sparkle in it, though of course, with her usual completeness she had already written out several scenarios of just that, with contingency plans of how she might find a new Magic and attune her with the old Bearers. (Trixie Lulamoon, for instance, was not completely crazy, and by all reports was shaping up to greater skill and mastery under Goldie Pie's tutelage in the hills of hoary, wonder-shadowed South -Dunnich).
One thing -- and one thing alone -- about the whole horrible incident made her smile to remember. That was the way in which Twilight's friends had sprung to Twilight's defense when they realized that Celestia had come to accuse her of warlockry. They had flung themselves physically between Twilight and herself, as if to physically-shield her from Celestia's wrath.
Another sort of Princess might have taken exception to that: it might technically be construed as incipent rebellion against the Realm. But Celestia fully-understood what this meant, and it made her glad: Twilight Sparkle had learned how to induce loyalty in her followers -- even in Twilight's most vulnerable state, seemingly out-of-favor with her liege lady, the other Element Bearers adhered to Twilight, stood by their friend.
That meant that Twilight Sparkle really had learned the key lessons of Friendship, and was therefore well on the way to Ascension. It meant that everything Celestia had done might prove justified by complete success.
But it had been close; so close. How could she make sure that nothing like this ever happened again to Twilight Sparkle?
Celestia looked into her mirror, brooding, falling into a brown study.
Hours passed.
There was a commotion without her door.
Celestia stirred, but was not much alarmed. Well she knew the nature of this tumult, the timbre of the voice raised in angry demand, the twin thumps against the wall near door-frame that meant her Guards had been shoved roughly aside by the intruder. She remained unworried, because the simultaneous flare of magic she felt was mere telekinesis, rather than the electrokinetic or gravitic bolts which the mage could have produced had she been really angry.
Celestia did wince at the sounds of her soldiers impacting the wall, because those collisions were probably rather bruising, and she liked her Guards. But these noises were not accompanied by any ominous cracking sounds of bones breaking, and she knew those Ponies were wearing armor. This could be viewed as as an unscheduled realistic training exercise: she reminded herself to authorize them combat pay for today and recovery leave, even if they weren't too badly hurt.
This was, after all, the fault of her own family.
Celestia sat up, turned in her seat, and faced the doors, ready to greet the intruder. She was not disappointed, as the intruder kicked those doors open with a single motion and strode into the room.
"Where is Twilight Sparkle?" the intruder demanded. "Is she still hale? What happened to her?"
"Good evening, Sister," replied Celestia sweetly. "To answer your questions in order: she is in Ponyville, at her Golden Oak Library when last I saw her; I left her shaken but sane, and in the keeping of Spike and her friends." She leanned forward and smiled reassuringly at Luna. "As to what happened to her, I think she suffered a delayed emotionally-traumatic reaction to the stress of doing battle with Discord. She became convinced that I required her to solve a Friendship problem in Ponyville, and when no such problem presented itself, she manufactured one. She enchanted a doll to be an Object of Desire. Which resulted in a minor riot, over possession of the Object."
Luna sat down, a combination of relief and shock apparent on her face. "Was anypony sore hurt?" she asked.
"No," said Celestia. "Fortunately, the physically strongest Pony in the riot was also a fairly gentle Pony. Big Macintosh Apple -- I think you met him, at the Welcome Home party Ponyville threw for you. He subdued the others with his might without severely harming any."
Luna nodded. "I remember him," she said, smiling. "A brave Apple -- and a good stallion." She returned to the subject at hand. "How far did Twilight slip toward Nightmare? And how did she escape her madness?"
"At no point did she manifest the stigmata of true Nightmare," Celestia said. "I do not think that she was ever really corrupt, nor as far as I could tell did any Night Shadow touch her. As to her escape, Spike sent me messages, and on my appearance I was able to shock her out of her obsession with a sufficiently stern mien. You've seen me do that before." She smiled, hoping to calm her Sister.
“Will she be all right?” Luna asked. Her expression was pleading.
“I believe so, Sister,” replied Celestia. “Understand, this was fundamentally a fear of rejection by my own self. Remember, Discord came close to overcoming her; she must have blamed herself for what she saw as her weakness …”
“She was not weak!” Luna interjected angrily. “She was under great pressure – Discord saw her as his main foe, and was no doubt crafting his strategy specifically to break her down – and not in a magical manner, which she might have reversed through her own magic, but rather by bringing her to despair of the loyalty of her friends! I know how he works …” That single pronoun was infused with deep hostility and loathing. “Twilight did not. It is a wonder she was able to resist him. That she was able to defeat him shows that she is a truly excellent Pony!”
“I know this,” said Celestia, placatingly. “And you played a key role in sending Twilight those old Friendship Letters. Which,” she went on musingly, “may have been why she became so fixated on writing Friendship Reports, in her recent madness.”
Luna shrank back, misery in her eyes.
“Oh, not that this was your fault,” Celestia said quickly. “Sister, you helped to save the day. What I am saying is that Twilight’s mind was brought to the brink of collapse by Discord, but she could not allow herself to collapse then, because such a collapse in the face of Discord would have been the final disaster. Instead, she forced herself to stay sane – and succeeded, because she is an incredibly strong Pony.” Celestia briefly smiled in admiration for Twilight Sparkle.
“Indeed she is!” affirmed Luna. “Discord took on more than he expected, when he challenged her."
“Yes,” said Celestia. Then she frowned. “But the price of such forcing her own mind to function under stress was that she inflicted long-term damage upon her own psyche. She was no longer wholly-rational, but she concealed her insanity well, even from me -- because she is extremely intelligent, and knows me very well.” She sighed. “Also, I was very busy, restoring order to a terrified Realm – I did not give her the time I should have, I was too ready to accept favorable superficial appearances where my Most Faithful Former Student was concerned.”
“Salvation had come from the Friendship Reports, so in her mind this was a life-line tying her to safety in the future – to managing to avoid failing me. So, when it chanced that life in Ponyville was proceeding smoothly; that there was no genuine problem to solve – well, she had to create a problem to solve. And, since the last time she’d been seriously casting it had been against Discord – she cast with too much strength, and created a really major problem.” She rubbed her forehead with one sungold-shod hoof.
“How close did she come to Nightmare?” Luna asked quietly. "I know she did not manifest it, but I also know that one can conceal the madness for a long time. I did."
“Mmm …” thought Celestia. “Less close than I feared? Understand, the course of study that is making her, that has put her on the road to Ascension … it is a very difficult one. She is an Avatar of something Cosmic, but to realize her Alicorn nature will require that she triumph, more than once, over extremely difficult and possibly dangerous problems. I have lost three or four students for certain to one or another madness, before her – but none of them were as close to Ascension as is Twilight now.”
“Thou doth walk a dangerous path,” commented Luna. “And leadeth thy students along it after thee.”
“I know,” replied Celestia. “Some of it was necessary to ensure that I could free you from your Nightmare,” she explained, “and some because we will have need of more Alicorn allies in the future. Right now, we are but three … too few, if we are assailed on all sides, as I fear we shall be before Equestria wins through to the bright future that awaits us after we have overcome our perils.”
“And Twilight Sparkle?” asked Luna.
“Her madness was minor, and temporary. She did not want to take over the Realm, or really hurt anypony. She mostly just wanted to please me. When she saw that her warlockry did not please me, she was apologetic and begged me for mercy. And then …” Celestia smiled at the memory. “Then her friends interposed themselves physically between myself and her, and pleaded her cause. They were not quite rebelling, but it was obvious to me that she had won their loyalty, their love. They would risk my displeasure to protect their leader, to save their friend.
“Understand this, Sister,” said Celestia. “Twilight Sparkle’s great flaw, when she first went to Ponyville, was that she was detached from other Ponies. She had no real friends … oh, she had playfellows and classmates, but she had little to do with them outside of school. Her love was wholly reserved for her family. Lacking friendship, she could not develop true charisma. Lacking love, she could not spark it from others. As a political leader, she would have been very competent, but cold … dutiful and loyal to the Realm, yet not really loving her own followers. Immortality and great power would in time have corrupted her, no doubt to one or another inequine political ideology.
“She has grown so much! The behavior of her friends made it wholly-apparent to me that she has learned how to be a friend, how to love others. Qualities which will serve her well as she assumes positions of power and influence. Power -- without love -- can too readily grow monstrous, even if its possessor does not actually go mad."
Luna nodded. "Clearly her friends do love her," she said. "Can she heal in the warmth of that affection?"
"Such is my hope," said Celestia, looking upward. "They are good mares, and each of them strong in her own way. Friends to her ... friends to our House ..." she looked at Luna. "They might, in time, become friends to you, as well."
Luna looked away. "I have done to them nothing but ill," she said in a low tone. "Forgiveness, I may have from them. little as I may deserve it. Friendship with them, I fear, shall never be mine."
"You got along well enough with Spike the Dragon," Celestia pointed out.
"I never did fight him directly," Luna said. "And we had ... a conversation. Mostly of necessity, and during which I plied him with gems most shamelessly. In any case, I have always been a Dragon-friend, when they would let me be such."
"You have had plenty of Pony friends as well," said Celestia. "Both before ... and now. Your Nocturnae are loyal, and many who are not Nocturnae as well. As always, dear Sister, you under-rate yourself. You are quite loveable."
"I am fierce," Luna said. "I frighten most Ponies. You are the one who is loveable."
"You do not frighten Twilight Sparkle," Celestia said. "She stood up to you fearlessly, even when you were in truth her deadly foe. I do not think she shall quail before you if you appear and offer friendship."
"She is a very brave Pony," Luna acknowledged. "But I do not see how I can do this. I have no excuse."
"You need none," said Celestia. "You are a free adult, moreover, a Ruling Princess of Equestria. You have at least as much right as anypony to go to Ponyville, seek her out, have converse with her."
"I am not always the most sociable of Ponies," Luna admitted. "Besides ... I do not know that she wants to see me. All I am to her is the Sister of her Most Beloved Teacher."
"She asks about you, sometimes," said Celestia.
"Really?" Luna's ears perked up. Then, hastily regaining her composure, "I suppose she makes polite inquiries, given that I am your Sister ..."
"More or less," said Celestia. "She asks how you're doing, and I tell her." At Luna's look of alarm, Celestia chuckled. "Not about anything that you'd much rather have the chance to tell her yourself, or would much rather not tell her yourself."
"I do not exactly live a wild and scandalous life, in any case," Luna mused. "I am much like any other Pony in a high military post. Working to reform our Guards, developing new weapons and engines of war, fighting monsters. Well, I suppose the last part of that is not that usual, but then Twilight does much the same thing there."
"You are not unlike her," Celestia agreed. "And I very much think that she would like to know you better, as well."
"Perhaps," admitted Luna. "But there is the shadow of the past between us. She was ... she has ..."
"Dusk Skyshine's Spark?" asked Celestia. "Yes, but that did not stop me from becoming her mentor, even though Dusk was our age when we were Sundreamer and Moondreamer Finemare, in our incarnations over four millennia ago. Indeed, it made me feel warmer toward Twilight Sparkle, knowing that she had the spirit of one who had been my beloved brother-in-law."
"It is more difficult," Luna pointed out, "knowing that she has the spirit of one who had been my beloved husband. And does not know this."
"Yes," acknowledged Celestia, "I can see where this might be ... uncomfortable. But ... Luna ... surely this does not make you hate Twilight Sparkle? I would imagine that it would induce the opposite emotion."
Luna flushed, and looked away, staring off sideways to the ceiling, and said nothing.
"Oh, Luna," said Celestia. "You're avoiding Twilight because you loved Dusk so much. Is that it?"
Luna closed her eyes, and nodded. Then turned and frowned. "No," she said, "that's not exactly right. It's not that I loved Dusk. I never stop loving anyone, unless he completely betrays me. And Dusk was never, either in word or deed, at all false to me."
She looked directly at Celestia. "I have had dozens of lovers in this incarnation," she said, "as Luna Selena Nyx. I am not wanton, but time passes ... and my lover dies ... and in time my mourning ends, and I love again. And," she said ... her eyes were moist ... "I have never stopped loving any of them." She smiled, half-bitterly. "I suppose that if all of them suddenly reappeared, living and lusty, I would be the most polyandrous Princess that ever was. I should need a building bigger than that one thou didst built out in the back garden to house them all!"
Now it was Celestia's turn to blush. "I never actually ..."
"I know," said Luna. "I did the research. We really should open that again as a bath-house, though I think we need a change of decor. Some of that statuary ..." she grinned. Then she sobered.
"But yes," Luna continued. "Dusk I loved, most of all, for he was the one true love of my first real Incarnation as a Pony. And ... he was a very good and noble and wonderful Pony. The finest stallion I have ever known. I wish our time together could have been longer ... he could have lived for decades more, had it not been for ..." She fell silent.
"I know," said Celestia softly. "But isn't it better that he's back now?"
"As a mare," said Luna. "I think thou dost perceive the problem here? In any case, he ... or she, as the case may be ... does not know me. If I come to her gushing of the love we once shared, I will terrify her. She will either think of me as a madmare -- or, worse, she will understand of what I speak, and be frightened for entirely different reasons." She slumped. "'Tis hopeless."
"You can simply befriend her again," suggested Celestia. "Her memory of her past lives will return to her, in time, if she Ascends."
"How can I befriend somepony who was once my husband, my true love?" asked Luna.
"How can you not?" countered Celestia. "Dusk was your friend before he was your lover or husband. Twilight is not precisely Dusk, but she is a good and honorable and kind Pony, who has many of the same virtues as Dusk. And she needs friends now, more than ever, to keep her sane while she walks the path to Ascension."
"That ... makes sense," Luna acknowledged. "'Tis hard for me, to extend my self toward Twilight, knowing what she was to me, and unable to tell her. But I shall try. To restrain myself, to not tell her too much, to be friendly." She thought a moment. "Does Ponyville have a Harvest Festival?" she asked. "In the past, almost any farming town would have big ones toward the coming time of year."
"Yes," replied Celestia. "Nightmare Night. A variant on the old All Soul's Night, Samhain as it was called in the time of the Tribes. But you should know ..."
"Very well," decided Luna. "I shall come to Ponyville on their Harvest Festival. I can make it a formal Royal Visit -- this shall allow me to avoid any awkwardness, and then it shall be simple enough to find an excuse to talk to Twilight Sparkle -- after all, she is essentially thine own Commander there, so it would only make sense for her to meet with me."
"Indeed," said Celestia. "I'm sure that she'll be thrilled to chat with you. But really, you should know ..."
"I shall appear in my full regalia!" declared Luna, springing to her hooves and flaring her wings full out. "Parade armor. Riding the Midnight Chariot! Ooh, she has never seen my Midnight Chariot! 'Twill be glorious!" Her voice rang out loud and clear, her ears and tail both rose. She looked supremely happy.
"Um ..." said Celestia, then reconsidered. She wanted Luna to connect with Twilight Sparkle, for both their sakes. The last thing she wanted to do was to discourage Luna from making the visit.
"Hmm, do you think that a whole company of Nocturnae would be too much?" Luna mused. "Perhaps 'twould. 'Tis meant as a royal visit, not a military campaign. I suppose the siege engines would be entirely superfluous ..."
"Oh, indeed," replied Celestia. "I would forget entirely about the siege engines."
"I defer to thine own sense of taste," Luna said. "'Twas ever better than mine. No siege engines, and I'll only bring a squad or so of my Night Guard. They may have other calls on their attention in any case." Her eyes shone. "But I shall definitely bring the Midnight Chariot! That is one beautiful vehicle." She smiled. "Dusk always did like fast cars."
"Twilight Sparkle," interjected Celestia.
"What? Oh, yes, thou'rt right." agreed Luna, with a look of mild disappointment. "Does Twilight Sparkle like fast cars?"
"Eh ... well, she likes my royal chariots," Celestia allowed.
"Close enough," decided Luna. "I shall announce this when ... No!" Luna got that dangerous look in her eyes, the one that showed that her artistic temperment was making its presence felt, and she was going to do something slightly reckless. She never got this way in actual warfare, but she had just been reminded that this wasn't, in fact, a military campaign. "It shall be a surprise!"
"Are you sure that's the best ..." Celestia began.
"Yes!" asserted Luna. She began rapidly pacing back and forth. "A surprise will have the most emotional impact. Ponyville will long remember the night I came to their Harvest Festival!"
Celestia was fairly sure that Luna was right about that. She wasn't sure exactly what they would remember about that night -- but she was happy enough that Luna was starting to become more socially-extroverted again, and not only in pursuit of her duties as High Lady of War and Guardian of Dreams, but in simple friendship and merriment.
However things developed, she suspected that Luna and Twilight would become better friends, and that entirely suited her purposes. The two would stablize one another -- the more if Twilight Ascended and hence would eventually be Luna's partner in government. While they were similar in some ways, enough to be kindred spirits and thus eventually very good friends, their differences usefully complemented one another.
"Yes," said Luna happily, "this shall be glorious! I shall assault the problem of Friendship with Twilight Sparkle, swooping down upon it out of the night sky in my Midnight Chariot, like a raider from the North, coming down from the stars to take my rightful place as her friend!" She made great sweeping gestures of her hooves and wings as she did this, though with such grace that she managed to avoid knocking over any of Celestia's furnishings.
Celestia smiled at her Sister. The way she was right now, it was easy to see why she had been Laughter. Luna in a good mood was incredibly merry, full of good-natured, gusty Joy, and it was impossible to remain sad around her. After Crimson Quartz had fallen into Shadow, and he had hurt Luna, that Joy had mostly stopped. Celestia had seen flashes of it again when Luna was with her friends, especially Snowdrop, but she hadn't seen it return completely until after her liberation, and this was more of it than she'd seen in well over a millennium.
Celestia very much liked to see Luna like this. If she was like this, then she most definitely was not falling back into the Nightmare. She thought that, in many ways, Twilight Sparkle might help her remember her Laughter.
She decided not to say anything about the nature of the modern Equestrian Nightmare Night. After all, Luna was happy, right now, and she would figure it out for herself when she did the research. Luna always scouted out the ground before a raid, in which nature she was clearly regarding her attendance at the 1501 Ponyville Nightmare Night.
She would do nothing to discourage Luna's enthusiasm.
After all, what was the worst that could happen?
Author's Note
Green Mountain marble comes from the Province of Green Mountain, located betwen Morgan Province and the Province of Royal Mountain, in northeastern Equestria. It is white, with greenish-gray veins, and looks nice with gold and sungold, which is why Celestia uses it for much of her decorating.
Celestia is hard on herself, demanding far more intellectual and moral perfection of herself than she does of anypony else. She always has been, always will be. It's a characteristic she shares with Luna. Celestia just conceals it better, that's all.
Celestia's own Beloved Teacher was, of course, Wind Whistler.
"Sungold" is Equestrian for an iridium-titanium-gold alloy, just as "moonsilver" is titanium steel. Very much unlike normal gold, sungold is quite strong and flexible, rather than weak and ductile. Celestia's regalia has also been enchanted to shed the tremendous heat she generates when using her powers at maximum intensity, so that she doesn't vaporize her own ornaments at such moments.
Dawn Starfall, also known as Breaking Dawn, is Scipio Smith's creation, from Vengeance of Dawn. There have been others -- I thought that two canonical and one fanonical breakdowns of students were enough. Anyway, I'm assuming that these were the worst cases, in the sense that they survived and turned to evil (at least for a while).
If they were really speaking English (or Gaelic, for that matter), "Samhain" would be pronounced "So-WAIN," nearly enough. It's the ancestor of our holiday of "Halloween" which is an erosion from the word which replaced "Samhain" when we became Christian, namely "All Hallow's Evening" (a desperate attempt to pretend that it was really about Christian Saints rather than the spirits of the dead visiting this world on the night when the gates between our world and the spirit world temporarily opened). I do not guarantee that the Tri-Tribal Pony "Samhain" was exactly like the Celtic Human one, though.
Since I was born on October 30th, I know that this is a very important holiday, really mostly about my advent! 
Once again: Luna loves her Midnight Chariot.
And so Luna is set firmly on course for "Luna Eclipsed," 28 days later. Appropriately, this is a Lunar Month -- and I didn't realize this until I just typed these words.
Causality can be tricky on the Cosmic Level, eh?
