Could such an audacious lie work? It seemed impossible that anypony would believe the events of this night, but so far they appeared to have been convinced. When she'd been transported back from the moon to appear in front of those ponies, she'd barely had a second to compose herself. To draw her first breath in a thousand years, to stand upon her own four legs. How had no pony noticed that she was as shaky as a foal, barely able to hold her own weight after all these centuries in chains?
She'd seen the fear in the eyes of the assembled crowd. No doubt, as her own image was ghastly to her, the sight of this nightmare made real would leave a lasting trauma in the psyche of many who saw it. Thankfully she'd still managed to transform herself into a phantasm and escape before any witness had seen through her display.
Her first stop had been to check that the group of ponies who were to vanquish her were on the correct path. Luna knew that her sister had seeded the tiny library in Ponyville with the correct volumes to provide all the clues needed to lead them to the Castle of the Two Sisters. She paused briefly to spy on them, and check that all the intended subjects were present. Indeed there were six, including the young unicorn who had spoken to her with such bravery at the failed summer sun celebration. In total there were two earth ponies, two pegasi and two unicorns. That felt like the correct mix, because all communities should be represented.
She's made her way to the Evergreen Forest. It's green embrace had always been wild, but over the last ten centuries it had become truly monstrous. The trees were thoroughly overgrown with creeping vines and the ground below was a carpet of tangled plants, locked in a life or death struggle to reach the sunlight. Only a handful of paths could be made out, where one trade routes had lead to and from the castle she and Celestia had called home.
The only sign of habitation was a small hut. It was adorned with masks, in a style that Luna was unfamiliar with. Who could possibly be living in this lonely and wild spot? That would be a question for another day, if there was another day after this for her.
Finally she arrived at the ruins that had been her home many, many years before. The last time she'd seen it, was the night of her battle with her sister. In that terrible fight the ornate windows had been smashed, rugs and tapestries shredded and even columns and walls smashed. The destruction of the home they'd shared barely seen in the fury and billing magical energy.
Luna had always assumed that the damage would be repaired and the castle would stll serve as the seat of government for Equestria. Now she could see that it had been abandoned long, long ago. Was the sight of their ruined home too painful for Celestia to bear? Perhaps she didn't wish to be reminded of that night, and the events that had led to it.
There was too little time to dwell on those long passed events though. Luna had to prepare herself to fool the ponies that would be pursuing her to this very spot. She had to make each of the embodiments of the Elements of Harmony acted in accordance with their true nature. Celestia had briefed her on each of the ponies that she'd manoeuvred into position, as skillfully as a grandmaster might move the chess pieces upon a board. None of these ponies knew they were pawns to her sister's schemes, but in truth Luna realised that she too was another piece upon the board being guided by that steady hoof.
These trials would be carefully scripted to have the appearance of true peril, without placing the ponies in any real danger. The aim was to educate, both the individual and the group, into the strengths that each pony brought and to start to strengthen the bond of friendship that would bring them together as a unified force. Eventually to deliver them to the castle, with all the puzzle pieces laid out perfectly for our band of heroes to put together.
Seemingly having taken no time at all they were here. They had all starred in their own little vignette, all to prime the young purple unicorn with what she needed to make that final leap of understanding. A final nudge to make her realise that she couldn't do this on her own was all that was needed. Luna carefully separated her from the herd, seemingly destroying the Elements of Harmony to make her see that she needed her friends.
Twilight looked defeated until the other five ponies came thundering into the room. When the young unicorn turned to face Luna she now had confidence about her posture, perhaps even a little swagger. As the Elements of Harmony reformed and blended with each of these individuals a blast of pure magical energy ripped towards the princess. The Elements did their new holders' bidding, and clawed deeply into Luna's mind. Unconscious of the masquerade which had been performed, the magical forces sought out a way to strip Luna of any means by which she could rule Equestria alone.
There was intense pain as abilities which had been core to the alicorn's very being were torn away. In an instant she knew that the sun would no longer listen to her commands. Though both her and Celestia had been able to command both heavenly bodies, and individually rule Equestria, Luna was now only able to command the moon. She could no longer challenge for supremacy without dooming their civilization to a dark, lingering death.
As the magical display started to subside Luna let her fearsome Nightmare Moon disguise dissipate. Sobs wracked her body as she now realised Celestia's true plan for her; that having her swear fealty was not enough to satisfy the jealous needs of her sister. She had been manoeuvred into letting herself be vivisected by this unwitting group of puppets. Would they have acted so cruelly had they known what they were truly doing? Luna didn't think so, but as her weeping was starting to turn to shrieks of rage her sister appeared.
With the unconscious grace that only a living goddess can possess, Princess Celestia immediately drew all other fuss and motion out of the room. With a glance towards Luna which clearly communicated that she still had to play along, or else the consequences would be fatal, the Princess of the Sun made a show of seeking reconciliation. Realising that she'd been manipulated, crippled and transformed into a servant, the tears that flooded down Luna's cheeks were genuine. She was barely aware of the words she was saying as the curtain fell on that terrible day's performance.