Author's Notes:

I want to apologize for this coming out a late as it has. I've been dedicating all of my writing time to my other fic and my co-lab, and that's why this is coming out as late as it is.

Rarity was having a good day. She had gotten a new dress order form Sapphire Shores, Sweetie was out with the cutie mark crusaders, and she had just finished with a personal project for when Princess Celestia and Princess Luna would be coming to Ponyville for the official meeting with the Yak leadership. Which was to say she was working on her own dress.

She was in the middle of getting the last of the fabric cut when she heard a knock on her door. "Just a minute," she said on sing-song, finishing with the cut she was on. Once she was one, she went to the front door and opened it. "Oh, hello, Twilight. How are you?"

"I'm doing fine, Rarity," Twilight said, a small smile on her face. "How are you?"

"Oh, just marvelous, darling. I just got an order from Sapphire Shores. She wants me to make a dress for her upcoming performance, and I can't wait to start on it."

"That's good," Twilight said. "Can I come in?"

"But of course, Twilight. Come in," Rarity said, and the lavender alicorn walked in behind the marshmellow unicorn. "So, anyhting interesting going on for you, Twilight," Rarity asked Once she had closed the door.

"Not much, really. I'm working on my own project."

"Oh, what is it?"

"Sorry, Rarity, but it isn't ready to the point I feel confident enough to show it to you. Once it gets there, though, you'll see it."

"And when might that be, Twilight?" Rarity asked curiously.

"Tonight, or that's what I'm hoping for, at least," Twilight said. It's a good thing Nightmare can dreamwalk like Luna, or this plan would be a bust.

"Well, I can't wait to see it, darling. I'm sure it will be magnificent."

"It will be, Rarity. In fact, I'm certain it'll change your life, but in a good way."

"Oh. Really. May I get a hint?"

"Nope. Sorry Rarity, but I don't want to give you any hints as to it. You'd be doing the same to me if you were making me a surprise dress, right?"

"I suppose," the unicorn said as she noticed the alicorns eyes. "Twilight, is something wrong? Your eyes look a little, how do I put this nicely, green."

"That has to do with the surprise, actually," Twilight said, mentally cursing herself for not covering those up.

"Well, it must be interesting, then. I can't wait to see it."

"Oh, believe me, Rarity, it'll be worth the wait," Twilight said. "Well, it was good seeing you. See you later, Rarity," she said as she walked to the door and cast a memory spell on Rarity that would prevent her from remembering these memories until the plan had succeeded. She opened the door and left, closing it behind her. She smiled to her self, and walked to her castle. When she made it back, she was welcomed by the sight of Nightmare Moon and Spike.

"Hello, Twilight," Nightmare said. "I assume you were able to put the spell in Rarity's mind?"

"Yep, along with the memory spell. As soon as you enter her dreams, it'll take effect, slowly, but surely."

"Excellent. It is a good thing Celestia decided I, or, rather, Luna, needed a break tonight, which allows for this," Nightmare said with a smile.

"True," Twilight said, "but I'm certain we would have found a way. Spike?"

"Yeah, Twilight?" Spike asked, saluting.

"Is the letter to Chrysalis ready?"

"Yep. It's a good thing we were able to get into Celestia's memories last night while she was asleep, or this wouldn't work. Want me to send it?"

"No, not yet. I'd rather have all three of us there to meet with her," Twilight said, excluding Spike entirely.

"Got it," he said before he walked off.

"'Tis such a shame that the young drake doesn't realize that Rarity doesn't like him the way he likes her," Nightmare said, "but it is a good way to ensure his loyalty."

"Too true, Nightmare," Twilight said, "too true. But what made you bring that up."

"How excited he looked when we told him we were bringing her into the fold. Did you not see his smile?"

"Fair point," Twilight said. "What should we do once Chrysalis' hive is with us?"

"Simple. Foalnap as many of Celestia's advisers and as many nobles as we can, and replace them with changelings. That way, we not only have good intelligence, but we have sleeper cells, as I believe the term is correct, as they will be waiting on our word."

"That's the correct use of the word, Nightmare, and that would be a good use of her hive."

"So, shall we prepare for my alternates arrival?" Nightmare asked with a small smile.

"Yes. We need everything at it's best, if only so we don't have to hear her complain about the decor."

"Then let us prepare."

. . .

That night- carousal boutique

Rarity was just finishing getting ready for bed, having already put on her mud mask and putting curlers in her mane. "Goodnight, Opal," she said to the pudgy cat that slept next to her bed. Sweetie Belle was with Applebloom for a sleep over, and wouldn't be back until that morning. She got into bed and used her magic to turn off the lights and put on her sleeping mask, ans drifted off, into the realm of dreams.

. . .

Rarity's dreams always had something to do with her job or aspirations, such as becoming one of the major fashion designers of the world, or even finding her Prince Charming (it was originally her Prince Blueblood, but that was completely destroyed after her first Gala.).

Tonight's dreams, however, were different. They were of her time as what her friends called 'Nightmare Rarity', but these showed that she was doing in justification of what had happened to Luna a thousand years before. They also showed her defeating her friends, and that Equestria had a new era of prosperity and fashion under her rule. Then, after all of those, they showed her friends, all but Twilight, Applejack, and Fluttershy, talking behind her back about how they shouldn't trust her, and how petty she was, which, she had to admit, became obvious with Discord.

"Why are my dreams like this", she asked during a particular one that showed her eventually being imprisoned by Celestia for the destruction, or, rather, 'redesigning' she had done to Ponyville a few weeks ago.

"Perhaps they are trying to tell you something," she heard a voice say from behind as the dream became one of the night sky. She turned around to see who it was that spoke and jumped back immediately when she saw Nightmare Moon.

"What are you doing here?" she asked, slight venom in her voice.

"My duty," the alicorn replied. "Unlike what so many other ponies think, I'm the one who manages Nightmares, for obvious reasons, though I usually appear as Luna, I imagine because I was a part of her conscience, but yours are the first I have appeared as myself, I imagine because of our. . . history together."

"So it was you who helped Sweetie Belle when she had that nightmare?"

"Yes, though, she wished for me not to tell you, I assume because she told you."

"No," Rarity said, relaxing slightly, "All she told me was that she had a nightmare, and you helped her."

"I suppose she wouldn't want to, given what it was about, but if she won't say, then neither will I."

"You still haven't given me a straight answer to my first question," the unicorn said.

"Like I said, they might be trying to tell you something. Often times, ones subconsciousness tries to tell them something of importance in dreams, though it is rare, and only happens with important events. And those must be acted upon immediately, and if I may advise, it would seem they are trying to say that you need to take up the mantle of Nightmare Rarity again for the betterment of Equestria."

"How do I know you aren't the one causing them?"

"Because I could have come up with much worse for this purpose , and even though I am seen as a monster, I wouldn't harm any who fall under my domain, which is to say dreams. Besides," the midnight-black alicorn said, getting closer to Rarity, "did you not think like how the dreams are saying you did originally?"

Rarity tried to recall, and, as much as she didn't want to admit it, Nightmare was right. "Then how do I become. . . that," she nearly spat put.

"That is best left to me," Nightmare said as she lit her horn, activating the spell Twilight had placed earlier. "When you awaken, your body will become that of your nightmare form, and you will have a slightly different conscience, seeing as how you are taking on a second entity, but it will still be you, for the most part, should you still want to go through with this."

"I do."

"Then awaken," Nightmare said as the world vanished in light. Rarity heard the alicorn say, "Come to Twilight's castle," before she awoke.

. . .

When she awoke, Rarity realized that she was slightly longer than her bed in length. She turned on the lights, and nearly hissed at the lights as she squinted, her eyes now being more sensitive to the light. After they adjusted, she opened her eyes and saw that her coat was now the same black it had been with Nightmare Moon. She got up and walked to her mirror and saw that she also had cyan, draconic eyes, and her mane was ethereal, like Nightmare's, with her tail being the same, but darker. Her cutie mark now had three, cyan rhombuses and four smaller white ones scattered among the three larger ones. Her horn was also longer

"It feels good to be back in this body, actually," she said before she remembered what Nightmare had said. She then teleported to Twilight's castle, though she was a little wary of what she would think.

. . .

Twilight's castle

"It is done," Nightmare said as she materialized beside Twilight. "She will be here soon."

"That's a relief," Twilight said. "I assumed that it would take longer."

"Well, I did take some liberties, such as saying I'm the pony who appears in dreams to help those having nightmares, as well as saying I helped her sister."

"Impressive, and you weren't exactly lying, either, seeing as how you were in Luna then."

Before Nightmare could reply, they heard a pop behind them, indicating teleportation, and they turned around to see Nightmare Rarity, as dignified as a princess, though without the regalia, standing there. She looked to Twilight and said, "Hello, Twilight," before she saw Nightmare, and said, "How is she here? I thought she only existed in Luna's mind."

"Before this week," Nightmare said, "that was true, but Twilight here found a way to reverse that, and now she is in mine."

"Really," Rarity said, an eyebrow raised. "Why?"

"To overthrow Celestia for the betterment of Equestria," Twilight said.

"Why," Rarity asked.

"Do you not remember the dreams?" Nightmare asked. "Celestia did those in secret with those who didn't deserve it. And do you not remember the diamond dogs. Celestia knew that they were there, but did not inform Twilight, which resulted in you being captured by them."

"Which means that it was her fault, you being captured, and then there's the fact she didn't let you know how much of a plothole Blueblood was," Twilight said.

"And don't forget the last time you were like this," Nightmare said. "She did nothing to free you from this form other then helping Luna bring the moon closer. Do you really want a ruler like that?"

"Or would you rather be a ruler that helps her subjects," Twilight said, using her magic to grasp two objects form behind her, and presented them to Rarity.

"My old crown and chest piece," she said in amazement, both at this and the fact that Twilight, of all ponies, had brought about a rebellion.

One that she found she had to help, if only to make life better for others.

She took the regalia, asking, "How did you find them, Twilight?"

"I just used a spell to bring them to me from where they were and used a reconstruction spell to remake them, really."

Rarity put on her regalia and said, "When do we meet our subjects?"