Celestia’s armored feet clicked across the beautiful tiling of her castle floors. The halls were eerily quiet, but there were still a few guards remaining. Almost all of them were now fully equipped with the old weapons: earth ponies with back-mounted rail cannons or hoof-fired energy weapons, Pegasi with under-wing particle beams, and unicorns vastly enhanced with armor ingrained with long forgotten magic.

Several more vaults had been opened. More weapons and armor had been deployed to circulation. As Celestia walked, she was passed by what was probably an earth pony coated entirely in strength-enhancing robotic armor, an tremendous artillery piece bolted to his back. He was headed toward the parapets of Canterlot, preparing to rain down fiery death on anything that dared approach the home of the Two Princesses.

Celestia smiled to the earth pony, and he stopped to salute. They both continued on their way, he to his station and Celestia to her quarters.

Outside, two guards were waiting for her. They were some of the last in the palace itself; under Celestia’s own orders, all guards had been incorporated into the main military body, aside from Luna’s chiropterans. Luna was weak, but Celestia was a goddess- -she required no guarding by mere mortals.

One of the two guards posted at her door was an earth pony, a white stallion with a back mounted multi-phasic laser. The other was a unicorn who was already beginning to show the fatigue of wearing the enhancement armor. He was shaking very slightly, and his eyes were twitching, as if he was seeing small things lurking in every corner. Before he saw Celestia, he also seemed to be moving his mouth, as if muttering something.

“Hello,” said Celestia, smiling.

“Princess!” said both guards stood at full attention and saluted.

“Oh, my,” said Celestia. “At…at ease.”

The soldiers returned to their normal position. Celestia had never gotten used to that aspect of military life. Although she had been a soldier long ago, until now, there had never been any need for her to be a commander.

She turned her attention to the unicorn. He seemed to look up at her, but his bloodshot eyes were shaking and unable to focus.

“You,” she said. “You have exceeded the duty cycle for your armor. You need to rest.”

“No, ma’am,” he said, his voice accelerated at manic speed. “I feel fine better than fine I am the defender of the faith I will not fail in the name of the Reich I will protect- -”

“The armor is not to be worn for more than twelve hours at once,” said Celestia sternly.

“But if I take it off I can’t focus can’t think can’t use magic can’t sleep and the bugs, the bugs come at night- -”

“Are you disobeying a direct order from your princess?” asked Celestia, still smiling.

“No,” said the guard, seeming to snap out of his distorted mental state. “No, ma’am.”

“Report to medical,” she ordered. “Get some rest.”

“Yes, ma’am, your highness.” His horn ignited with blue-green light, and he instantly vanished, teleporting away.

“Your highness,” said the other guard.

“Yes,” said Celestia.

“With all due respect, I do not believe that alone I will be able to properly protect you.”

“Then go reinforce Luna’s security detail.”

“Your highness?”

“I can take care of myself. You do not need to worry about me. But Luna is very sick right now. Please, protect my sister.”

“Yes, your majesty!” said the guard, saluting, and then slowly lumbering away under the weight of the weapon on his back.

Celestia continued to smile, and magically opened the door to her chamber. She entered, and then gently closed the door, sealing the room sonically to ensure that she would not disturbed.

Her smile quickly faded, and with a scream, she tore of her helmet and threw it against the floor. It bounced almost comically and skidded across the ornate mosaic below.

Five thousand years of work, of careful planning, had all been destroyed in a matter of days. She had spent centuries painstakingly purging all of the advanced weapons from Equestria, erasing any mention of them in history, funneling propaganda into the people so that they would forget their horrible and violent past. Then, in one swift motion, she had released those very weapons onto Equestria.

Just minutes earlier, she had stood on the balcony of her grand castle, smiling as she explained to her subjects that for their safety, Equestria was now under martial law. A beautiful kingdom of peace and happiness had, in a matter of days, become a military state- -a state with her as the Supreme Overlord.

She tore away her armor, slamming it into her furniture with her magic. She had devoted her life to peace, to creating a better Equestria- -she had even planned to phase herself and Luna out of true rulership, allowing the mortal ponies to rule themselves under the watchful eye of the protector goddesses. All that hope was gone now, destroyed at her hoof. She had reintroduced the weapons she had sought to destroy. Unicorns were already becoming addicted to their armor, and being driven mad by the enchantments on it; no doubt the technology for firearms and energy weapons would soon find its way into the general population, and into unsavory aspects of the population. Soon ponies would find out just how easy it was to kill each other- -or rather, remember it.

Celestia burst into tears, and dropped to her knees. In the name of saving Equestria, she had destroyed it. It still existed in body, but its soul had been blackened.

It had been necessary. In her mind, she was able to justify it. The logic of what she was doing made sense. She had been wrong about the threat that Equestria was facing. Initially, she had misunderstood what a Choggoth actually was. She has seen its form, and fought it, and she had thought that was all it was, a mass of ghastly protoplasm with claws and tentacles and teeth.

In truth, it was far worse. Sightings had already been reported across Equestria of ponies fitting the Choggoth’s pony-mimic form. They had been confirmed by soldiers: they were found to be infiltrating cities unnoticed, stealing various things and entering high-security targets. What they stole was almost always magical artifacts, but they also took long-forgotten curiosities from museum basements that only Celestia remembered the purpose of. Even Pegasus cities were not safe. Numerous weather factories had been sabotaged, and relics form the especially martial Pegasus past taken away.

The infiltrators were not easy to track. The original D27 had been strange looking and indefinable, but his new versions had improved: they were found to wear wigs and false tails, and have painted-on cutie marks. They could not stand up to close inspection, but they were good enough to fall into the background until it came time to strike.

Soldiers had hunted several of the clones. Almost inevitably, the Choggoth pieces would collapse and disintegrated before being caught. If one did choose to fight, they rarely caused much damage and were defeated relatively easily.

Not all the battles had been successful, though. There had been casualties. Some of the Choggoth pieces that chose to fight managed to severely injure soldiers that attacked them. There were some Pegasi who would never fly again, and other ponies who had lost limbs.

There had even been several deaths, and that saddened Celestia desperately. Most of them had to do with soldiers using their weapons improperly, resulting in overloads or friendly fire incidents. At least once, though, a soldier had unloaded an entire plasma cartridge into a blue pony who had turned out not to be a Choggoth at all.

A backlash was already occurring. Ordinary ponies were reacting angrily, and their anger was becoming directed at blue ponies. Several local governments had already created internment camps to contain them, and Celestia’s soldiers spent almost as much time suppressing anti-blue riots as actually fighting D27.

The condition was far worse than anypony knew, though. According to geologists, Choggoth components had been detected in well water: they were hiding in aquifers. Since no poisons were known that could affect Choggoths without effecting ponies, there was no way to get them out. The water, likewise, was considered contaminated. Entire cities and agricultural communities had been driven into drought conditions.

In all the chaos, Celestia’s rapidly growing army had been spread thin. The defense of Canterlot fell to her, which was not difficult. She had produced a shield of magic around Canterlot. Unlike the weak shield that Shining Armor had used during Celestia’s botched Cadence assassination attempt, this one was virtually impregnable. Since Twilight had still not returned with information about the nature of Choggoths, Celestia had been forced to make her shield defend against any being who she did not know personally. Anypony or anything that she did not know needed to be inspected thoroughly before being allowed in. Even the pinpoint Gloame portals that the Choggoths seemed to be coming through could not be opened beneath the solar-white dome of magic.

The point, of course, was Luna. Equestria itself was secondary. The whole reason Celestia had created a peaceful Equestria was for her sister, who was no collapsing mentally in a different part of the castle. The Choggoth had already shown that it wanted Luna dead, and Celestia was sure that when it finally gained enough strength for an invasion, it would try to take Canterlot and Luna with it.

That was something she could not allow. That, she realized, was the true purpose of all of this. She had to defend Luna. That was the true reason she had become a god, and the purpose that she truly believed she existed for.

The conditions the world had fallen into broke her heart. It tore at her very sole, and she ached inside. She wept for her pony children, and for the life she had now throne them into, and for the world she had failed to make for them and for her sister, and for her beloved Twilight, a Princess of Friendship who was now thrust into what was sure to be a long and brutal war.

Celestia looked around her chambers, and saw that she had made a mess of things. Damaged furniture lay everywhere, and a picture of her with Twilight lay shattered on the ground. One of the only things that had escaped her rage was a small table near the door, on which was a platter with a cupcake.

Celestia grabbed the cupcake in her magic and greedily shoved it into her mouth. It had been left out too long and tasted rotten, like swamp gas, but she ate it anyway. Worse, there was only one. Celestia stood, tears running down her face. She needed fifty more of them, at least, a tub of fall-flavor ice cream, and several bottles of distilled golden-apple wine. She did not even bother to attach her armor, and left her chambers without any ornamentation. There were hardly any guards to see her anyway, and it hardly mattered. She just needed something to make the sadness stop.

Luna lay on her bed, shaking. She stared into the distance, her eyes focused on a single point on the wall. There was nothing special about that point, but she found that by focusing on it with all her might, she was able to prevent her mind from wondering.

She had not moved in days. She had not been able to. The necklace was keeping her secure, but even it was starting to fail. The things beyond her mind were growing stronger, and finding new ways into the realm of her consciousness.

Cavern Melody was safe, and that was one of the only things that kept Luna sane. That she had nearly killed the pregnant chiropteran pony, however, was what allowed the sickness to bore deeper into her mind.

Luna turned over, and, after hesitating, looked down. She gasped, and felt dizzy. Her flesh was intact and uninjured, but she might as well have witnessed a festering, maggot-filled wound. The dark stain around her cutie mark was reaching father up her body, and down her legs. Pieces of it stretched out like an infection, and wherever they touched became numb and strange to her- -as if it belonged to a different pony entirely.

The door slowly creaked open to her room. Luna blinked; she had been hallucinating continuously for some time, and was not sure if the door was actually opening this time. It seemed to be real, though.

Her suspicions were confirmed when a jarringly white figure stepped through the door. Luna was still sane enough to recognize her beloved elder sister. Celestia approached like a light in the darkness.

“Sister,” she slurred. Luna could smell the scent of pumpkin and golden-apple wine on her sister. She was drunk, and she had been crying.

“Sister,” said Luna. “Something is wrong. What…what has happened.”

“I’ve…failed,” hiccupped Celestia. She stumbled her way into the room, and Luna smiled- -only to realize that Celestia’s shadow had eyes.

“No, no,” said Luna, trying to pull herself across the bed. “Not that.”

Celestia paused, confused, but her shadow did not. It stepped forward, resolving and separating, its form solidifying. It became an image of Nightmare Moon.

“Just a hallucination,” said Luna, holding her head. “Just a hallucination.”

“For now,” said Nightmare moon.

“Stay back!” cried Luna.

“Sister,” said Celestia. “I’m sorry. I never meant to hurt you. I never meant for this.”

“She’s a bit denser than the Choggoth,” said Nighmare Moon. She had reached Luna’s bedside, and reached out a black hoof toward Luna.

“No,” whispered Luna. She did not know what to expect, but she would have rather been touched by the most hideous of monsters- -or even the Choggoth itself.

Instead of a blow, or an infecting, burning touch, the black hoof began to stroke Luna’s mane.

“There, there,” said Nightmare Moon. “The change is always harsh, and never easy, but it is so much more so if you resist it.”

“Please, sister,” said Celestia. “Please forgive me for what I did. I never meant to leave you. I never wanted to…I just thought…” Celestia rushed forward, and cast herself on Luna’s lower body, pinning her mostly numb legs to the bed. Celestia was weeping. “And now Equestria…I threw all of it away!”

Luna could barely listen. Her eyes were wide and fixed on the shadow-pony that was holding her head and shoulders, gently calming her like a mother with a sick and frightened foal.

“Why are you here?” whispered Luna.

“Because you are the only thing in my life that matters to me,” said Celestia. “You are the only thing that has ever mattered! The only reason I am not alone…”

“I have seen the totality of time,” said Nightmare moon, softly. “And although if I were to remember it, I would be driven mad, I can see that something is coming. A time of war. A time that was not meant for you.”

“I don’t understand,” said Luna, softly.

“I only sent you to the moon because I had to. Because I couldn’t cure you alone!” sobbed Celestia. “And I’m sorry! I had to, but it was the hardest thing I have ever done!”

Nightmare moon smiled, her lips parting and pulling back farther than any normal pony’s should have. Her pointed, fanged teeth became visible. “Because I need your body,” said Nightmare Moon, softly.

“NO!” screamed Luna suddenly. She kicked Celestia off her, and disengaged from Nightmare Moon- -who was nothing more than an illusion that converted to mental smoke as she pushed it away. Luna dropped off the edge of her bed, and forced herself back into a corner, holding her legs near her. “No! I’m not Nightmare Moon! Not Nightmare Moon!” She felt her horn glowing with magic, but she did not know where to aim it. Her mind could not well differentiate which of the two ponies in the room was Nightmare Moon, and was Celestia. Her mind could not determine which was truly evil, and which was truly good.

“Sister,” said Celestia, tears running down her face. “I know…”

“So do I,” said Nightmare Moon, resolving into a shadow form of herself. “I am. And I need to be reborn into this era. Only you can let me in.”

“Just leave me alone,” whispered Luna, feeling the hot sting of tears in her eyes. “Please.”

Celestia frowned, and for just a moment looked as old as she truly was. Silently, she lifted herself from Luna’s bed. She turned and looked at her sister, but then went to the door. She left, and slowly closed it behind her.

“Sister…” whispered Luna through her tears. “Please don’t go…”

Nightmare Moon remained, her unblinking eyes staring from the darkness. “You will succumb eventually,” she said. “That device you wear has a finite power source. The time is drawing near. We could not destroy the Finality Core in our own time, and it will activate. It must. Every second you resist me, your mind is torn, and I weep for you. But know this, Luna. Just as the moon passes in phases, so do we. I will return to Equestria.”

The eyes faded, and the shadow vanished into the recesses of Luna’s mind. Luna only sat, rocking, slowly sobbing.

“No,” she said, forcing her fear away. She paused for a moment as the idea resolved in her head. She dried her tears, and she shakily stood. She knew what had to be done. “You will not have Equestria. You will not hurt my sister, or my friends. I will not let you.”