My Little Pony Equestria Girls 3: Twilight's Shadow

by Revan

Rating: everyone
Tags: Adventure, Equestria Girls, Sunset Shimmer, Main 7 (EqG), Princess Celestia, Human, Main 6, Spike
Length: 11630

Eight months after the events of Equestria Girls 2: Rainbow Rocks, a new threat arises that not only threatens Equestria, but also every other dimension in existence - and it's Twilight Sparkle!

Eight months after the events of Equestria Girls 2: Rainbow Rocks, a new threat arises that not only threatens Equestria, but also every other dimension in existence - and it's Twilight Sparkle! Twilight has faced many threats to the safety of Equestria over the years - but can she face down herself? And what part does Human Twilight play in all this?

Published 2015-03-11 00:40:02 UTC
Last updated 2015-07-07 17:54:52 UTC

Chapter 7: On the Brink of the Abyss

After Spike explained the situation to Twilight and Sunset, silence fell. Sunset eventually spoke.

"Well, lead the way, Twilight," she declared, gesturing her arm in Twilight's direction.

Twilight was startled. "Me? I'm completely new to this stuff. I didn't even know that Equestria existed 24 hours ago!!"

Sunset smiled patiently at her. "You are the human version of Twilight Sparkle. You will be able to sense the passages that we must take in order to get to her inner mental stronghold."

Spike asked, "How are you so sure that she has one?"

Sunset replied, "It's the only way that she could have held out this long against her alter ego." She looked at Twilight, her hair seeming to gleam brighter than usual. "You recognize it, don't you?"

Twilight hesitated. "Yes, I do." It felt almost exactly like the way she had felt in high school - a voice which wanted to lash out, to inflict pain on others, rather than receiving it. A desire for power, fueled by a bottomless hatred.

As if it was a cue, a voice started to speak in her head.

Interesting. A Twilight from another world. It chuckled, then continued, One which has not been as fortunate in her life, one filled with more pain and anger. It then shifted its tone, becoming cajoling and persuasive. Join me, Twilight. Become one with me. You need not suffer any more...

Twilight shivered. "Dark Twilight," she whispered aloud.

Sunset Shimmer frowned. "Is that what you called it?"

The voice continued. Come. Our power will be limitless! All will adore you, begging for your friendship! You shall be their absolute ruler, with freedom to live as you choose. You shall be able to punish those who have hurt you, and assist those that truly deserve it. All you have to do is to join me.

Twilight fought to not give in to temptation. It was so enticing, so logical.

"If I join you, what would you have me do?" she asked.

Both Spike and Sunset looked at her, concern written on their faces. "Uh, Twilight? Are you okay?" Spike queried, unaware of the mental struggle Twilight was currently in.

First, you must slay these intruders. Then assist me with breaking Twilight's mental redoubt. Once that is done, then I shall be free, and infinite power shall be ours.

Twilight shook her head. "You want me to kill my FRIENDS??!!"

Sunset and Spike were on the edge of panic now. "What are we gonna do, what are we gonna do?" Spike hyperventilated. Sunset was now up in Twilight's face, shaking her and yelling at her to snap out of it.

Twilight's attention, however, was elsewhere.

The voice sneered. Friends? FRIENDS??? They're not your friends, they're the friends of Pony Twilight. They don't know the REAL you - not like I do. Its voice became persuasive again. What say you, Human Twilight? Will you join with me and become powerful beyond your wildest dreams?

Twilight opened her mouth to reply, the fate of two very different worlds on her shoulders...

Author's Note

If you like this story, don't forget to hit the like button. Also, if you don't like this story, don't just click the dislike button; leave a comment detailing what you don't like about it. One can never learn from one's mistakes if one doesn't know what said mistakes are.

Chapter 8: It's a Madhouse In Here...

Something has gone wrong. We don't seem to have an archived copy of that chapter.

Interlude: WHAT???

Author's Note

WARNING: THIS CHAPTER WILL MAKE YOU FEEL EXACTLY LIKE ITS TITLE. DON'T WORRY; THIS IS A NORMAL PART OF THE MATURA-

Shoot. Wrong alert message.

But seriously, this chapter is supposed to make you be like "WHAT???" It's intended to give a somewhat comical break before plunging you back into the storyline.

Please tell me how well I do at this task; and don't forget to like the story if you like it!! (AND NO TROLL DISLIKES!)

Additionally, I apologize for writing such short chapters; I just merged Chapter Eight and Chapter Nine into a new combined Chapter Eight, and I'll probably go back and merge the rest of them later.

So, enjoy a short break, courtesy of both Pinkies. :pinkiehappy: :pinkiehappy:

Interlude: WHAT???

"WHAT???"

Human and Pony Rainbow Dash stared at one another. Then, remembering that there was a horde of changlings chasing after them, they shook their heads in unison.

"We'll talk about this later."

ERROR MESSAGE 0198724365: FOURTH WALL BROKEN
CAUSE: PONY PINKAMENA DIANE PIE AND HUMAN PINKAMENA DIANE PIE
ATTEMPTING TO RESOLVE ISSUE...
WARNING: UNABLE TO RESET WITHOUT DESTROYING MULTIPLE REALITIES
RESET ANYWAY? Y/N

"Hey, look! There's text on that white screen over there!"

"It's the author writing about us; leave him in peace, otherwise we'll be deleted from existence."

"Can you please return to your home reality now? I'll chat with you later."

"CUPCAKES!!!"

"Hey, MY [REDACTED] JUST BAKED THOSE!!!"

"Here's some cupcakes from another reality! Don't worry, they're exactly the same as the ones we just took!!"

INTRUSION INTO AUTHOR'S IMAGINATION SECTOR "EQUESTRIA" SUBSECTOR "TWILIGHT"S SHADOW" ENDED
INTRUDERS RETURNING TO BASE DIMENSIONS...

"Well, at least that explains where the cupcakes in Chapter 6 came from..."

Chapter 9: The Fifth Force of Nature: The Pinkie Pie Force

Author's Note

Don't forget to click the like button if you enjoy this story!

Chapter 9: The Fifth Force of Nature: The Pinkie Pie Force

"Did you see?" Pony Pinkie Pie asked her human counterpart.

"Yes, I did. It doesn't look too good", Human Pinkie replied. She frowned - an expression that one did not normally see on Pinkie's face. "Can we get there fast enough?"

Pony Pinkie nodded. "We can, but I'll need your help."

A surprised Human Pinkie said, "Me? But you're the dimension-hopper! I don't normally tap into alternate dimensions!"

Pony Pinkie winked. "You're me, silly! Or, at least another universe's version of me - which is close enough, since I've never met another Pinkie that couldn't dimension-travel."

"What if I'm the first?" Human Pinkie wondered.

"I can tell that you're not, since you were able to follow me when I jumped into another dimension to get us some cupcakes!" Pony Pinkie spoke reassuringly, hugging Human Pinkie.

"Okay. How do we do it?" Human Pinkie asked, the hug ended and her confidence restored.

Pony Pinkie smiled. "Well, first we need to-"

NOTE: ON ACCOUNT OF THE FACT THAT THE REST OF THIS CONVERSATION CONTAINS ADVICE THAT ONLY PINKIE PIES CAN UNDERSTAND/UTILIZE, THIS CONVERSATION HAS BEEN DELETED FROM THE HISTORICAL ARCHIVES

"What the-?"

"I did not just see that-"

"Karking pony just stole my LIGHTSABER-"

"Madam, the Ghost Rider recon drones just reported something I think you better see-"

"It appears that fairies aren't the only non-human intelligent life forms, Butler-"

"AAHHHH!!!-"

Twilight was drowning.

Not literally drowning, but mentally drowning. She could hear Spike and Sunset, but they sounded so far away...

The anger, the hatred, was rushing in. She desperately tried to block it, but she was pushed back, the torrent rising around her.

Kill them...Kill them all...make them suffer...

NO!!!

Yes...torture them...make them feel pain...punish them...they were never there for you...

NNNOOOOOOOOO!!!!!!!!!!!!!!!!!!!!!

YES...they deserve it...

Twilight could feel the water rising, could feel it covering her lips, her nose as she desperately tried to breath...

All was lost.

FOR EQUESTRIA!!!!

A massive explosion of light occurred, and an avalanche of people, vehicles, and technologies poured into Human Twilight's mind.

She was never able to describe it afterwards, but as she saw the charge, led by Pony and Human Pinkie Pies, she also sensed the many lessons all had to teach about truth, justice, morality, love, friendship, and the existence of God.

Twilight suddenly opened her mouth and screamed, I WILL NEVER SURRENDER TO EVIL!!!!!!!!!!!!!!!!

The darkness, now on the defensive, was startled. WHAT???.

Twilight raised her arms, and exploded in a wave of golden light. The darkness was banished from whence it came.

Twilight collapsed, and suddenly, the two Pinkies were there, and everyone else was gone.

"You can't give in now; you have to save your other self!!" both Pinkies said in perfect unison.

Twilight stood. "You're right." She closed her eyes, and Twilight returned to Pony Twilight's mind...

Chapter 10: As Unity Holds Out, One Must Go Alone

Sunset Shimmer was getting desperate. Despite all that she could do, the wall of red that surrounded Human Twilight would not yield. In fact, from what she could determine, it was getting stronger.

Spike looked at Human Twilight with tears in his eyes. He'd only known her personally for a very short time, but he'd grown up with her Equestrian counterpart, and from what he could tell, she had a very similar personality to 'his' Twilight.

Then there was a massive explosion, and Sunset and Spike were hurled away, hitting the far side of the 'cavern' wall. Sunset coughed, and looked up just as Twilight Sparkle hauled herself to her feet.

"Twilight?" Spike asked uncertainly.

Twilight coughed, and then replied, "I'm still me."

Sunset quirked an eyebrow. "I hope you don't mind if I scan in order to confirm that."

Twilight nodded, and Sunset closed her eyes, performing a rapid but thourogh scan of Twilight's mind. She detected nothing dark - not even a single trace of darkness was left in Twilight's mind.

"You're clean," she said, and stepped back.

Twilight cocked her head. "I see that you're in pony form now," she observed wryly.

Sunset spoke up quickly. "I can change back if you'd like-" she began, only to be interrupted by Twilight's upraised hand.

"No, stay in your original form. I like it." She smiled and added, "Has anyone ever told you that you're beautiful?"

Sunset was taken aback. She thought about her past. Now that she mentions it, I believe that the last person - or pony - to do so was Princess Celestia, and that was before I started to become power-hungry.

"Not in a long time," she replied. "But - thank you."

Twilight smiled, but then her face creased into a worried expression. "We need to hurry. Sunset, can you carry me and Spike on your back?"

Sunset was thrown off-balance once more. "I think so. Why?"

"Because I know exactly where we need to go - and we need to move fast."

"Alright, but I hope you're sure that you know what you're doing," Sunset sighed as Twilight swung herself up onto her back. Spike climbed on, and Sunset Shimmer galloped in the direction that Twilight was pointing.

Meanwhile, everyone else, pony and human alike, had met up with each other. Unfortunately, they were under attack.

"Oh come on! How many more stinking changelings are going to attack us?" Pony Rainbow Dash complained as she dogfighted with a bunch of Rainbow clones.

"Personally, Ah think that the fact that they can't imitate humans is a blessin'," Human Applejack shouted back in response. She was currently engaged in a boxing match with a convincing duplicate of Princess Celestia.

"While we're counting our blessings, I believe that Fluttershy's stare is immensely helpful," Pony Rarity added, as she kicked an especially nasty specimen of Timber Wolf in the face. The wolf howled in pain, and Human Rarity, who had managed to imagine a very fashionable, jewel-encrusted - as well as useful - flamethrower, torched it with a jet of flame.

At the same time, the two Fluttershys were holding back an entire army of minotaurs, which were facing the nightmarish proposition of facing not one, but two angry Fluttershys, both of which were giving the stare and the worst scoldings that they had ever gotten in their lives out to them.

"While I may not be a fan of Pinkie's antics under most circumstances, they're certainly being effective," Human Rainbow Dash noted as she played her favorite guitar at a volume level which, if done in real life, would have made it impossible to communicate with anyone else, and would have caused instant deafness. As it was, she had every changeling within three hundred feet on the floor, grabbing their eardrums and howling in pain.

And her statement was true, for the two Pinkies were pulling out all the stops - playing never-ending tag, wielding party cannons, burying their opponents in an avalanche of cupcakes, cakes, and other pastries, bouncing and even teleporting at an incredible rate, and generally causing mass pandemonium.

"Yes, but Ah don't think that we can hold out forever," Pony Applejack said, even as she ran circles around a horde of Parasprites.

Unfortunately, that was also true. Despite everything that they could do, they were being forced back - slowly, perhaps, but steadily.

Come on, Twilight...

"Is this it?"

"Yes, I'm certain of it."

Twilight dismounted even as Sunset cautioned, "That doesn't look like it's going to grant easy entrance."

The that that Sunset was referring to was the gigantic set of locked doors that stood in front of them.

Spike spoke up. "I'm getting a bad feeling about this."

Twilight walked up and put her hands on the door handles. "She's inside."

"But where is Dark Twilight?" Sunset asked.

Suddenly, a burst of maniacal laughter filled the air. Sunset instinctively turned around so fast that Spike fell off of her back.

"I'm right here, Sunset Shimmer," Dark Twilight said, striding forward. An entire armada of powerful foes/former foes stood behind her.

"Twilight, get inside!! I'll hold them off!!" Sunset shouted as she fired up her horn.

Twilight was torn inside. "But I can't let you fight them alone!!"

"I was a student of Princess Celestia. I won't go down easily."

"But-"

"GO!!!!!!"

Twilight placed her hand in an empty handprint that was next to the set of doors. The doors glowed a bright purple, and began to open.

"STOP HER!!!" Dark Twilight commanded. The armada rushed forward.

Sunset Shimmer was there to meet them. She engaged in magical and physical combat even as Twilight slipped inside and the doors began to close.

Dark Twilight howled in frustration, and streaked after her like a bolt of lightning, managing to slip inside just before the doors closed...

Chapter 11: Confrontation

Something has gone wrong. We don't seem to have an archived copy of that chapter.

Chapter 12: The Fate of Two Universes

Author's Note

This merges Part one and the second part, so if you've already read the first part, scroll down and start reading after the horizontal line.

Chapter 12: The Fate of Two Universes

Sunset Shimmer rolled, charging her horn and firing a beam of intense orange-white heat at the dragon that confronted her.

The dragon shrugged the hit aside, as Sunset mentally berated herself for not remembering that dragons swam in pools of lava for fun. It opened its mouth, and Sunset braced herself, a shield spell slamming into existence around her.

But the jet of flame never came, for Pinkie Pie came out of nowhere with an enormous cannon, and it wasn't loaded with confetti.

The dragon opened its mouth just in time to get a giant mouthful of over ten thousand cupcakes. The heat of its flame fused the cupcakes together, and sealed its mouth shut like glue. The dragon inhaled through its nose in surprise, right as the second wave of cupcakes came hurtling in.

A number of cupcakes in the second launch were inhaled into its nose, and the dragon's airways were now completely blocked. It atempted to exhale, but the cupcakes in its nose were too tightly lodged. Next it tried to breath flame, but that enhanced the gluelike qualities of the melted cupcake mass in its mouth.

The dragon reared and began to thrash about, clawing at its face. Sunset grabbed Spike and teleported about twenty meters away, joining Pinkie Pie, who stared at the form of the thrashing dragon with an unusual grimness.

"What did you make those cupcakes with?" Sunset asked Pinkie in hushed tones.

"Rubber cement, gorilla glue, corn starch, cake batter, and frosting," was Pinkie's somewhat terse reply.

Spike looked at Pinkie Pie with newfound respect. "I didn't know that you could do something like that."

Pinkie continued to stare at the dragon, whose struggles were now beginning to die out. "I've never had to kill anyone before," Pinkie said with a tone of undeniable sadness.

Sunset found herself at a partial loss for words. "Pinkie, I didn't mean to make you have to-" she began, only to be interrupted by Pinkie.

"No, it's not your fault. It was bound to happen sooner or later if I kept on helping my friends in defending Equestria from major threats, and I accepted that it might happen after I became the bearer of the element of laughter. Besides, I was protecting one of my friends, not killing it for killing's sake."

Sunset was startled by Pinkie Pie's newly-revealed depths, and in that moment she understood Pinkie far better than she had ever had before. Then one sentence suddenly leapt out at her, and she said, "Pinkie? Which friend were you refering to?"

Pinkie cocked her head. "Why you, silly!"

Sunset was now getting thoroughly confused. "But-tt you-u barely even know me?!!" she stammered.

Pinkie looked at Sunset. "Just because you've only known a friend for a short time, doesn't make them any less of a friend," she stated.

Sunset fell silent, contemplating Pinkie's words, and the undeniable truth contained in them.

Spike interrupted her thoughts. "Uh, not that I want to break this up, but we've got to help Human Twilight!"

Sunset shook her head rapidly. "Right!"

They ran past the 'corpse' of the dragon, which was slowly starting to dissolve, towards the huge set of doors.

Only to encounter a problem: The doors wouldn't open.

After an indeterminate amount of time in which they tried everything possible - and some impossible things - to get the door open, they had to admit defeat.

"Twilight's alone in there! We have to assist her!" Spike hollered, banging rapidly on the doors.

"It's no use. Even I can't get through," Pinkie spoke in an exhausted tone.

Sunset looked up at the doors, silent and implacable. "All we can do now is pray and hope for the best."

Ka-BOOM!!!

Human Twilight dodged once more in desperation, as yet another magical fireball detonated, taking another chunk out of the library's bookshelves.

The bedroom's floor had collapsed early on, and now she and Dark Twilight were locked in a deadly dance, each one trying to get to Equestrian Twilight, but also attempting to prevent the other from reaching her.

Fortunately for Human Twilight, the normal laws of physics didn't seem to apply here with 100% consistency, which had allowed her to do things such as run along the ceiling. But she needed to make a break for Equestrian Twilight soon: She was tiring, while Dark Twilight seemed to be indefatigable.

"GAAHHH!!!!!!!!!!"

Twilight screamed in pain as a magical tentacle of dark energy finally snagged her. She was hung upside down as Dark Twilight gloated.

"At last! Now Twilight's body - and all of reality shall be mine!!!" Dark Twilight cackled in malicious glee. She then turned, walking slowly towards Equestrian Twilight's sleeping consciousness.

As Dark Twilight walked away from her, Human Twilight fought against her bonds, but was unable to get free. Then, just as Dark Twilight stretched her hoof towards Equestrian Twilight's forehead, Human Twilight remembered something that the Equestrian Pinkie Pie had said to her as she headed back to her counterpart's mindscape.

You're just as powerful as my Twilight in terms of magical potential. You just haven't figured out how to tap into it yet - but it will answer your call when you need it most.

Now Twilight reached inside herself, and she found something there. She called it forth.

"YARRGGGHHH!!!!!!!!!" A beam of purple-white energy burst forth, hurtling towards Dark Twilight with the force of a freight train.

"What-" Dark Twilight was hurled away, punching through the library's wall. And Human Twilight, suddenly freed from her bonds, made a leap that would be impossible in the real world, reaching out for her counterpart.

"NOOO!!!" Dark Twilight called in desperation, but it was too late - for Twilight's hand reached out and touched her other self.

Equestrian Twilight's eyes snapped open, and gazed into Human Twilight's eyes. No explanations were needed.

"Let's do this," Princess Twilight Sparkle, Princess of Friendship, and wielder of the Element of Magic, said in absolute confidence.

Chapter 13: Who Said Saving the World Is Easy?

Human Twilight and Equestrian Twilight turned to face their foe. Dark Twilight looked at them, and then laughed.

"Well done, Twilight Sparkle. But you made one mistake. When you banished your equivalent of me from your mind, you shattered its personality - but not its power."

Equestrian Twilight gasped. "Oh no..."

"What? What did I do?" Human Twilight asked in concern.

A mist of darkness rolled in. Dark Twilight lit her horn, and the darkness spiraled inward towards her horn, like water going down a drain.

"Quick, get her!" Equestrian Twilight screamed, and both Twilights unleashed a massive magical blast.

Dark Twilight was flung away - but the dark mist rushed to her horn, and disappeared.

"Come on, we've got to finish her!" Equestrian Twilight hollered, and Human Twilight swung herself up onto her counterpart's back. "Hang on!"

Equestrian Twilight spread her wings, and took off, soaring high above the 'ground' below. Human Twilight noted that the library had faded away, replaced by a featureless plain of granite.

Dark Twilight stood below them, and unleashed a beam of black-purple energy. Equestrain Twilight dodged, and then pulled into a steep dive, her horn charging up. Human Twilight placed her hands in front of her and concentrated, her hands glowing a vibrant violet.

Twin blasts of destruction hurtled towards Dark Twilight, who spread her wings as the blast front hit. A massive plume of dirt headed upwards, mushrooming out towards the 'sky'.

"Did we get her?" Human Twilight asked.

"AARRRGGGHHH!!!" Dark Twilight bellowed as she rocketed towards their position, encased in a sheath of black-violet energy. Equestrian Twilight generated a shield spell, saving them from destruction, but causing them to fly upward, hitting the 'ceiling' of the 'cavern'.

"Grrr," was Equestrian Twilight's response. She then pushed off, speeding like a bullet at Dark Twilight.

Human Twilight then did something that made Equestrian Twilight question her sanity: she jumped off.

"WHAT ARE YOU DOING??!!!" Equestrian Twilight cried in surprise, unable to stop her charge at Dark Twilight.

Human Twilight did not answer her, and closed her eyes.

Dark Twilight cackled. "Suicide, Twilight? Really? I thought that you were better than that."

Then, as Equestrian Twilight continued her onward rush, Human Twilight snapped open her eyes, and a thermonuclear warhead appeared underneath her, perfectly visualized thanks to her extensive knowledge of physics and chemistry.

Equestrian Twilight came on like a runaway freight train, and impacted Dark Twilight, who shielded herslf but was knocked to the 'wall' of Twilight's mind.

"Is that the best you can do?" Dark Twilight taunted, spreading her wings in preperation for takeoff.

"TAKE COVER!!!"

Dark Twilight snapped her head around, looking at Human Twilight.

She saw a projectile of some sort, hurtling towards her. "What?"

The five-megaton nuke detonated, and Dark Twilight was hurled outwards, the outer barrier of Twilight's mind shattered.

"NOOO!!!"

Human Twilight then jumped up from behind her lead shield, and concentrated, causing a temporary seal to form around the breach.

"You have to seal it!!" she called to her counterpart, who was stepping forward from behind a lead barrier that Human Twilight had visualized.

"I will," Equestrian Twilight promised, smiling at her. "But you need to return to your own body now."

"I know," Human Twilight said. She turned to go, but was halted by Equestrian Twilight once more.

"Yes?" she asked.

"Thank you. For everything."

Human Twilight smiled. "Hey, that's what friends are for." She turned then, and leaped, seeing a brightness as she flew through the air to the edge of Twilight's mind.

Celestia and Luna saw a dark mist shaped like a pony being suddenly ejected out of Twilight's head.

"Now," Celestia said, and she and Luna locked horns. Before the darkness could get its bearings, a shield of gold and blue materialized into existance around it, trapping it.

The darkness pounded furiously at its newly-created prison, but was unable to make so much as a dent.

Celestia and Luna's horns glowed once more, and the sphere began to contract.

The darkness thrashed around furiously, but still could not escape. The sphere continued to shrink, and eventually shrank to the point of having a radius of zero, obliterating the personality known as Dark Twilight forever.

Celestia sighed in relief, and turned to the sleeping ponies on the floor. "Well, that is one crisis averted."

Luna stood next to her, and added, "Now all that remains is the clean up."

Celestia looked at her, then stated, "And the explainations."

Luna nodded her head in assent, then asked, "How much do you wish to tell them?"

Celestia answered, "I do not feel that we can tell them everything. I still cannot go a day without thinking about how she died."

"She is not dead yet," Luna reminded her sister.

"She might as well be," was Celestia's response, and the two stood there quietly, thinking of their shared loss.

Luna broke the silence. "Twilight Sparkle might be able to find a way."

Celestia sighed once more. "Yes, she might - but if I inform her, then her friends will eventually learn of it - and you know that the protection spells we set up around her will kill them. Twilight will be able to pass safely, but they will not - and we did set up the spells to be as close to impossible to undo as we could." Then she paused. "Although there might be a way..." She shook herself. "Now is not the time, Luna. We must take care of our various responsibilities."

"Agreed," was Luna's reply, and they turned their thoughts back to the tasks at hoof once more.

Chapter 14: Painful Memories

Something has gone wrong. We don't seem to have an archived copy of that chapter.

Prolouge: The Corrupter Arises

It was the middle of the night in Ponyville - a night that seemed peaceful and ordinary, a night that, while cold, was crisp and clear, with not a cloud to obscure the light of the full moon. But this was not an ordinary night - for deep within the Everfree Forest, something stirred from its slumber.

It arose, and at first all that one could see - or would have seen, if anypony had been awake at that hour to see it - was a darkness, without definitive shape or form, hovering over the trees of the Everfree Forest. However, in scarcely a moment, twin beacons of red ignited, and the shadow coalesed into a smoky outline of a pony, with the two blazing spots of red being where its eyes should have been.

The darkness looked up at the sky. It was a cunning creature, a being with no space - or desire - in its mind for things as frail as emotions. It quickly came to the conclusion, based on the positions of the stars, that it had been ten thousand years since it had last walked upon the land of Equestria.

Although it did not have emotions, it did have a need, an ingrained drive to make more of its own kind. However, there were no others of its kind left - not that it would have mattered. For its kind had never created new ones in partnership, nor had its kind ever needed to do so.

But before a new one of its kind could be created, it needed to find a suitable... target, for lack of a better word. The only kind of target, that it could... use, however, was an Alicorn pony - and, it quickly determined from the incredibly faint scents in the air, there was only one nearby.

No matter. One would do just as well as a thousand - probably better, in fact. It sprouted smoky black wings and a horn as black as obsidian, and silently flew towards Ponyville - and Twilight Sparkle's castle.

It flew through the walls - after all, it had no tangible body to speak of - and found itself in a bedroom, with a sleeping pony that- it quickly checked - had both horns and wings. It felt a sense of satisfaction, and quickly entered the pony's mind.

It found what it was searching for, and, quietly dodging the alicorn's sleeping consciousness (which was engaged in a weird dream involving a pink earth pony, muffins, and an immature dragon), broke down the barriers that contained it. Then it departed, flying back to the Evergreen Forest to sleep for ten thousand more years.

And the thing that it had unleased started to fester within Twilight Sparkle's mind...

Spike awakened, yawning quietly. He lay there for a moment, quietly savoring the feeling of warmth that permeated his body. He felt like he could stay in his curled-up position forever - but he couldn't, since Twilight would drag him out of there sooner or later. He sighed, and for the first time since he had moved with Twilight to Ponyville, gave in to the inevitable and got out of the bed.

Only then did he realize that Twilight was still asleep. He checked the window, and saw that the sun was already a quarter of the way across the sky. He frowned. Twilight should be up by now, Spike thought to himself. She's always awake before I am.

Spike climbed onto Twilight's bed, and crawled towards her. He shook her. "Twilight? It's time to be up and about." There was no response. He frowned again, starting to worry. He shook her again, harder this time. "Twilight?"

Suddenly, Twilight bolted upright in the bed, causing Spike to tumble off. He picked himself up, and said, "Well, your trusty dragon assistant actually got up before you this fine morn-"

Spike was cut off as Twilight's appearance registered on him. Something was very wrong. She shouldn't have gray eyes, nor had she had a black horn last night. And why was her cutie mark ringed in red?

"Twilight? What's happening to you?"

She answered, but her voice came in gasps. "I'm...not certain...Spike. But...send a message...to Princess...Celestia...immediately!"

"Okay, I'm on it!" He grabbed a scroll and wrote down her condition hurriedly. He sent it via dragon-breath, and three minutes later he received a response. He opened it and handed it to Twilight. As she read it, her eyes widened. Then she magically lifted her quil pen and started hurriedly writing on another scroll. She handed it to Spike, and said, "Spike, follow...the directions here, but first...knock me out."

Spike's eyes widened. "But Twilight-" he began.

"NOW, Spike!"

"Okay, okay! Just give me a second!" He grabbed the first thing that came to hand - the book Twilight had been reading last night - and whacked her hard across the head.

She slumped to the floor, clearly out of it. He grabbed the scroll, grimly certain that whatever was going on, it was not good. He opened it , and saw one sentence, which said:

"Take me to Canterlot and contact Princess Celestia."

Spike shook his head sadly. Today, he was supposed to be assisting Rarity by taking delivery of three rare rolls of crystal silk at the train station and bringing them to her.

Well, that was going to have to wait. He had a mission now, and no pony - or dragon - or griffon - or, heck, any swarm of changlings - was going to stop him from completing it. If there was any pony whom he would give his life for - besides Rarity, of course - it would be Twilight Sparkle.

He looked at Twilight's body, and sighed. "Well, I hope that Princess Celestia knows what's happening to Twilight, because I certainly don't!"

Spike grabbed Twilight's front left leg, and began to drag her towards the bedroom door - and the cure for whatever had afflicted Twilight Sparkle. He hoped.

Chapter 1: A Crisis in the Making

Spike was very keyed up and tense. The life of his best friend, Twilight Sparkle, was potentially hanging in the balance, and what was he doing?

Sitting on a couch inside Canterlot and watching Pinkie Pie, Rainbow Dash, Applejack, Fluttershy and Rarity worry about Twilight's health. Not the most productive use of his time - but what else could he do? He'd gotten Twilight to Princess Celestia, as Twilight had told him to - and as he had promised himself he would do - but now he had to wait as Celestia, after magically teleporting Twilight's closest friends into Canterlot and explaining the situation to them, cryptically told them to wait here as she "analyzed the condition" of Twilight.

Now he waited, looking on as Pinkie Pie was literally bouncing of the walls - and then winced as Pinkie Pie accidentally landed on top of Rainbow Dash.

"AARRRRGGHHH!!!! PINKIE!!!" Rainbow Dash screamed in pain and irritation.

"What? It was an accident!" Pinkie Pie responded, temporarily coming to a halt - of a sort, as she was still bouncing up and down - on the aquamarine carpet.

"You just mussed up my wing feathers! Do you realize exactly how long it takes to arrange those so that drag is reduced!?"

"Hey, would you pipe down? We've got bigger problems than an accident to deal with", Applejack interjected.

"Yes, poor Twilight is facing a potentially life-threatening malady", Rarity chipped in from the red velvet chair in the corner, as she continued to sow an aquamarine dress made out of crystal silk - a material that was only made in the Crystal Empire, which was now availiable for the first time in a near-millenium. Normally, Spike would be incredibly happy to see her, but under these circumstances, he was so worried about Twilight that he had to concentrate - hard - in order to think coherently.

"Especially since even Celestia has to go research through her private library in order to find out precisely what it is", Fluttershy joined in quietly from the maroon sofa, where she was fluffing Angel's tail.

"Well, still-" Rainbow Dash began.

"Enough", a voice rang out commandingly. Spike - and everypony else in the room - turned their heads.

Princess Celestia had returned from her reseach and observations. And, judging from her body language, the news she was bearing wasn't particularly good.

"My worst fears have been confirmed", Celestia said heavily. "Twilight Sparkle has been attacked by a Corrupter."

Pinkie reacted first. "Not a Corrupter! Anything but that!" She then leaned towards Rainbow Dash and whispered, "Do you know what that is?"

"Beggin' your pardon, Princess Celestia, but I don't have any idea what a 'Corrupter' is", Applejack stated.

Celestia briefly closed her eyes, as she answered, "An ancient creation of evil - one I'd hoped had finally been ended forever." She opened her eyes and began to speak once more.

"A long, long time ago - long before Equestria was founded - a terrible war swept the land. This war was not waged just with mere weapons, but with magic - deep and powerful magic, magic that could instantly heal or kill, magic that was able to level mountains and raze forests, even magic capable of freezing oceans and triggering volcanos. On one side were the forces of Light, and on the other were the forces of Darkness. The forces of light were fighting to preserve the land that would become Equestria, while the forces of darkness wanted to destroy it, and then rebuild it according to their designs."

"Victory for the forces of light was assured, for they outnumbered their enemies two to one. But that victory did not come quickly. For hundereds of years, the war raged on. The original form of the landscape was obliberated, as conflicting spells intertwined and armies clashed."

"Many terrible creations were made by the darkness during the war. The Corrupter was one of them, and it survived the war's end and the forces of darkness's defeat and banishment. They were all eventually hunted down and destroyed - or so it has been thought."

Fluttershy shivered. "I don't like the sound of that."

"So, you are saying that Twilight has been attacked by one of those... things?" Rarity queried.

"It is much worse than just an attack", Celestia replied. "It has managed to find Twilight's alternate personality, and has unleashed it."

Spike, already on the edge of an emotional prepice, asked "Can't you do anything for her?"

"No, I cannot. It has already progressed to the point that any attempt I might make to reimprision her alternate personality, which identifies itself as 'Dark Twilight', would simply make the situation worse. The only reason that it has not already taken her over is because Twilight is unconcious, and therefore able to devote all her energies to fighting it", Celestia answered.

"Hang on a second. Isn't being unconcious supposed to make people less focused?" Rainbow Dash interjected.

"Correct, Rainbow Dash." Celestia nodded in Rainbow Dash's direction. "However, Twilight knows how to harness magic inside her own mind, and therefore, she is more focused, not less, when she is in a trance state."

"A trance state? And how do we get our Twilight back?" Applejack demanded.

"Although I cannot do anything, you can - if you are prepared for the potential consequences", Celestia told them.

"Are you kidding me? Of course I am!", Pinkie Pie (who had stopped bouncing when Celestia entered the room,) responded.

"If it means Twilight gets to come back to us, then I'm in!" Rainbow Dash declared.

"Well, I, for one, am perfectly willing to do so", Rarity stated with her usual eloquence.

"Well, I'm joinin' in this one, for certain", Applejack answered.

"Well, this sounds...dangerous, but if Twilight's life is at stake, then I'll come", Futtershy asserted.

Spike looked at everypony and spoke. "Twilight's my oldest friend. I will do anything to save her."

Celestia nodded. "I would expect no less from Twilight Sparkle's closest friends." She then surprised everypony by adding, "But not the only close friends of Twilight."

Everypony was startled by this statement. Spike wasn't, however. He knew exactly what - or, to be more precise, whom, Princess Celestia was referring to.

"You mean Twilight's friends from Canterlot High, on the other side of the magic mirror."

Celestia nodded. "Precisely. Even Twilight may not realize exactly how deep an emotional attachment she has to them. In order for this to work, her close friends from both worlds must be represented. We will need all of them - and one other, if she exists."

"Now, this is what we're going to do..."

Chapter 2: The First Day

August 28, ****

Twilight Sparkle sighed. Today was the day she went to the Empire college, one of the original members of the Crystal League and rated as one of the top schools in the country. This was her top pick for college, so why was she so nervous?

She turned away from her breakfast of oatmeal, stood and looked out the window, and sighed once more, as she made herself face an uncomfortable truth.

She was afraid. Afraid of what the culture at college was going to be like - and how she would fit in. Sure, at her high school, she had been withdrawn and rather lonely, but she had also been used to it. Here, the social life on campus was going to be an even bigger factor than ever before - and she was pretty sure she knew what was going to happen to her.

Her gut clenched, as she remembered her stormy social past. Outcast. Ridiculed. Shunned and banished, victim of venomous slander - whenever the student body had bothered to take any note of her at all.

It hadn't always been that way. Back in elementary and middle school, she had been liked. Respected, even. But that had all changed in her freshman year of high school, due to a girl named Sunset Shimmer.

Twilight had wound up dedicating the summer before her sophomore year of high school researching Sunset Shimmer. She had discovered that, up to the summer after eighth grade, Sunset had been a sweet, kindhearted person - until her parents were killed in a car crash.

Sunset had been in the car - and survived. However, due to complications from infection of the injuries she had sustained in the crash, survival came at a brutally steep cost to Sunset Shimmer. Her arms and legs were amputated, replaced by prosthetic limbs.

And she had apparently lost her originally happy disposition because of it. The Sunset Shimmer that emerged from the wreckage of that car was bitter, and obsessed with power. She quickly outmaneuvered the legal guardian that was appointed by the courts to watch over her until she came of age, gaining access to all the money that her parents had left behind.

She first used the money to upgrade her prosthetics. Then, she invested the remaining money in various companies, stocks, and bonds - all of which soon started to roll in large sums of money. Then, once school started in the fall, she moved into the social life of high school with just one goal - complete and utter domination of the school.

One of the first moves she made was to reach out to Twilight, asking for her to become one of her lieutenants. Twilight had considered the offer - and refused, stating that she was here primarily to learn, not to rule over the school.

And Sunset Shimmer had made her pay dearly for that refusal. By the end of the first quarter, she had consolidated a powerbase. By the beginning of the third quarter, she had ruthlessly crushed all opposition to her rule. Her grip on the school had been unyielding - as had her hatred of one Twilight Sparkle.

Twilight had responded to Sunset's ruthless persecution by withdrawing into herself, throwing everything into her love of science and research to compensate. The teachers praised her, giving her high marks for her work. But the wrath of Sunset Shimmer did not abate in the following years.

Twilight had hoped that, once high school was over, she and Sunset Shimmer would part ways. But she had discovered last week that Sunset Shimmer was also going to Empire - and that was after the final payments had been collected.

Twilight's thoughts were disturbed when Spike, her dog, came up next to her and nudged her with his nose.

"What? Oh, it's just you, Spike", Twilight said, scooping up the purple puppy. Then she glanced out the window and realized that the bus which she planned to ride on in order to get to Empire was pulling up to the corner.

"Gotta go! I love you, Mom!" Twilight called out as she hurriedly grabbed her backpack and duffel bags. The voice of Twilight Velvet drifted into the room as Twilight Sparkle dashed out the door.

"I love you too, and good luck at Empire!"

That afternoon, Twilight Sparkle sighed in relief as she made it to her dormitory room, number 715. She grabbed her newly-issued key, but just as she was about to unlock the door, she heard a voice, one she'd hoped to never hear again.

"Hey, look what the dog brought in."

Twilight grimaced, and, quickly pocketing her room key, whirled around to look down the hallway - and came face-to-face with Sunset Shimmer.

"I was wondering what had happened to you", Sunset Shimmer continued. Twilight saw, with some surprise, that Sunset's prosthetic legs and arms appeared to have been upgraded yet again.

"What do you want, Sunset Shimmer?" Twilight demanded, hoping that Sunset couldn't see how her body quivered in fear.

"I want you to assist me in taking over the school", Sunset replied, smiling with the total self confidence of the apex predator who knows its prey is terrified.

Twilight stared. "You've got to be kidding me? This AGAIN? What makes you think that I'll be any more willing to help you than the first time?" she stated incredulously.

Sunset Shimmer's smile became even more predatory. "I believe I can persuade you otherwise", she stated, advancing a step towards Twilight. Twilight instinctively backed up. But before she - or Sunset Shimmer, for that matter - could act further, a voice came out of the night:

"What's going on over there?"

Before either of them could react, a body came out of the darkness and tackled Sunset Shimmer. Sunset went flying; only the automatic reflexes programmed into her prosthetic limbs prevented her from getting a serious head injury.

But Twilight wasn't really paying attention to that. She was too busy gaping at the person who had tackled Sunset Shimmer, who was just getting up off the floor.

It was... Sunset Shimmer. Either that, or an identical twin, which Twilight knew for a fact couldn't be the case. This girl looked exactly like Sunset Shimmer, except for the fact that she was perfectly healthy and had no artificial body parts.

"Give it up, me. You should know to act better than this", the healthy Sunset stated. Twilight noticed that behind her stood five other girls, but she was still so shocked that the information was essentially ignored by her brain.

Now the original Sunset Shimmer glared up at the second one.

"YOU DESTROYED MY LIFE!!!"

She launched herself at the second Sunset, and Twilight thought, Well, I guess this corner of the world is about to become real ugly.

Chapter 3: From Sunset to Sunset

CRAAACCKK!!!

The sound that a Sunset Shimmer makes when she tries to punch herself - and misses, Twilight Sparkle thought numbly to herself.

The second Sunset had dodged out of the way just in time. But now there was a jagged-edged hole in the wall, through which Twilight could see a college dormitory room - which was (thankfully) unoccupied at the moment. The Sunset that Twilight had known for over four years growled, pulling her arm out of the wall, as the new Sunset turned towards her again, spreading her arms in a placating gesture.

"Relax. No one's trying to hurt you", said the second, healthy Sunset Shimmer. The original one glared at her again.

"Oh? And how am I supposed to trust any word that comes out of your mouth?" she asked sardonically. "You are the one who destroyed my LIFE!!!" She swung again, her enhanced prosthetic arm coming in at a blindingly fast speed.

THUNK!!!

One of the girls that had been standing behind the second Sunset Shimmer had leaped and brought down the first Sunset in a flying tackle. She had a head of rainbow-streaked hair, Twilight noted, her mind still partially paralysed by the unexpected appearance of a second Sunset Shimmer. How was such a thing even possible?...

Her thoughts were interrupted by another girl, this one with straight pink hair and yellow skin. "Uh...Rainbow Dash?"

"What? Can't you see that I'm-AAGGHHH!!!" The old Sunset Shimmer had grabbed Rainbow Dash's arm and twisted it in the wrong direction. Now, as Rainbow hunched over in pain, she kneed her in the neck, pushed her aside and rose to her feet once more.

"Well, it looks like Rainbow needs my assistance", a different girl, this one with blond hair and wearing a cowboy hat, drawled with a southern accent. She then proceeded to first unleash a roundhouse kick into the first Sunset's midriff, which knocked her down again, and then proceeded to jump on top of Sunset. They rolled away, wrestling each other.

"But what does she mean when she says that you destroyed her life, darling?" the fourth girl stated. This one had purple hair and white skin, and appeared to be the fashionable one of the group, Twilight noted. Her mind was starting to recover from the initial shock of finding another Sunset Shimmer, allowing her to think clearly.

The second Sunset looked somewhat uncomfortable. "Well, I-" she began, only to be interupted by the last girl, who was a walking advertisment for the color pink.

"Back when you were still evil and had just arrived from Equestria, you found out about her, and you decided to get rid of her, because you didn't want anyone seeing two of you walking around, which might have caused people to start asking questions that you couldn't answer, so you caused her and her parents to get into a car crash, in an attempt to forstall the problem permenantly!!" she stated very rapidly.

The new Sunset Shimmer gaped at her. "How did you know all that?" she asked.

The pink girl shrugged. "Just a thought."

And Twilight Sparkle was now in a state of shock once again.

The old Sunset grabbed the blond girl's left leg, and executed a sudden throw. She flew smack into the wall beside Twilight, and lay there, out cold. Twilight stared at the girl, wondering, How did my life turn into such a madhouse?

The girl of pink gasped. "You just hurt two of my best friends!" She began to glower at the original Sunset Shimmer, who had just finished brushing herself off and had fallen into her "combat-ready" pose. "And nobody does that! NOBODY!!!" She moved swiftly.

"Pinkie Pie!!" The cry came from the second Sunset, but it was too late - for the wrath of Pinkie had been unleashed.

She dodged the arms of the first Sunset, headbutted her in the stomach, and then, as Sunset gasped in surprise and pain, Pinkie brought her right leg behind Sunset's legs in a knife-like motion, dropping her to the floor. Then, she straddled the first Sunset's body and grabbed her around the throat. As Twilight looked on, the girl with the yellow skin spoke up.

"Ah, Pinkie? I think that there's been enough fighting for today, don't you?"

Pinkie looked at the healthy Sunset. "Do you think that there's been enough punishment? Or do I need to bring out the cupcakes?"

The second Sunset Shimmer hesitated for a moment. "Let her go, Pinkie Pie."

Pinkie Pie released her hold on the original Sunset's throat and rolled off her. She came up in a crouched position, in case Sunset wanted to resume the issue.

But the first Sunset Shimmer didn't. Instead, she stared at the second Sunset, her face full of surprise. After a moment, she spoke.

"You spared me? Again?" she said, somewhat incredulously. Then her face darkened with anger. "Oh, wait, let me guess. You've spared me just so that I can suffer some more?!"

The new Sunset looked back at her, and Twilight could see pain etched into that gaze. Pain that spoke of mistrust, suspicion, and an inability for some to forget - and forgive.

How can I get such clear impressions from a person I've barely even met? Twilight Sparkle wondered. She didn't know if there was an answer.

"I've changed. I'm not the person I used to be", the healthy Sunset stated. She looked at the other Sunset, her eyes pleading to be believed.

The first Sunset laughed, her voice filled with dark humor. "And I'm supposed to just take your word on that?"

The girl with the purple hair spoke. "It's not just her word. It's also mine."

"And mine", Pinkie Pie chimed in.

"I vouch for her as well", the girl with the yellow skin said quietly.

"I trust her." This came from Rainbow Dash, who was helping the blond-haired girl to her feet.

"And me also", replied the girl, with a bit of a drawl, due to her southern accent.

The original Sunset looked at them for a moment uncertainly. Then her face hardened.

"It'll take more than words to convince me", she declared.

"I wouldn't expect anything less from me, me", the new Sunset Shimmer said wearily. "But you need to change yourself."

"Oh really?", the first Sunset spoke scornfully.

"Yes. You need to abandon your ambitions for power", the second Sunset replied.

The old Sunset snorted. "Just so that you - or somebody else - can take over? I don't think so", she retorted. She turned to walk back down the hallway. "And this isn't over", she called back to them.

After she rounded the corner, the healthy Sunset turned to the blond-haired girl and asked, "Applejack, are you all right?"

Applejack responded. "I reckon that I'll be okay. Isn't the first time I've conked my head."

Twilight interrupted them. "Hang on a second. You're the girls from Canterlot High - the ones right at the center of the space-time anomalies!!", she said as her brain finally came out of semi-paralysis and began working at high speed again.

The purple-haired one looked at her. "Why do you refer to it as something foreign when you were right there in the center of it all?"

Twilight was thrown off-stride. "Wait, what? I certainly wasn't there, so what are you talking about?"

The purple-haired girl opened her mouth to reply, but the new Sunset Shimmer spoke first. "Rarity", she said to the girl, "this isn't the Twilight Sparkle we know. This is the one from this world."

"There's another one of me?" Twilight inquired, her curiosity coming to the forefront.

The healthy Sunset Shimmer looked at her and sighed. "Well, you're up to the neck in this thing now, so come along with us and I'll explain what's going on to you."

Twilight's sense of wariness and her burning curiosity wrestled with each other. Curiosity won. "Okay", she replied, taking Sunset's outstretched hand.

As they began to walk away together, Twilight thought, I've got a feeling that what I've seen so far is only the tip of the iceberg.

Chapter 4: When the World Goes Upside-Down

Twilight Sparkle set down her mug, quizzically looking across the table at Sunset Shimmer and the other girls. They were sitting inside their large college dormitory room. Twilight idly wondered how they had managed to get this room. Large college rooms weren't that easy to get, after all. She then mentally shook herself and returned to the task at hand.

"So let me get this straight. There's another world, one inhabited by talking, magic-using ponies, pegasi, unicorns, and unisi, which you call "alicorns", plus other species, and they're linked to this one by a magic portal?"

"Yep" was the reply from the blond-haired girl named Applejack. The others nodded their heads in confirmation.

"And the time-spatial disturbances that I've recorded are incidents where magic has been used by you and others?"

Once again, everyone nodded.

"And in addition to that, there are pony versions of everyone in this world?" They nodded for the third time.

"And the Sunset Shimmer that is sitting in front of me is the one from Equestria?" Twilight said, gesturing to Sunset, who was wearing a turquoise shirt with an orange-and-red sun on it.

Sunset sighed. "Yes, I am."

Rarity spoke up. "I know it's all a bit hard to take in, darling. Heavens knows that I was a bit put out the first time I heard Spike talk."

Twilight stared at Rarity. "Hold on a second. Equestrian Spike can talk?"

Fluttershy answered. "Yes, he can. Back in Equestria, he's not a dog at all."

Twilight snorted. "I suppose that he's a pony then?"

"Nope. He's a dragon!" Pinkie Pie stated cheerfully, as she guzzled down a strawberry milkshake.

Twilight's jaw dropped.

Rainbow Dash interrupted the silence. "So, whaddya think? Are we kosher or not?"

Twilight paused. Conflicting emotions played across her face, and the others leaned forward to hear what her answer would be.

Twin voices argued inside Twilight's head.

They're playing you for a fool, Twilight Sparkle, the first voice warned her. Another world, inhabited by ponies? Don't be ridiculous.

But it would explain the space-time anomalies that you've been detecting for months, the second voice argued. And it also covers why there are two Sunset Shimmers.

The first voice snorted. Magic? Another version of YOU? You're going off your rocker, Twilight Sparkle.

But look at them. Do they look like they're lying? the second voice replied.

They could be mistaken, the first voice said desperately, sensing that it was losing ground.

You could always just ask them to demonstrate their magic, the second voice answered. That would settle the question.

Twilight came to a decision. "You said that you get longer hair and wings when you play music?"

"Yeah. And it's totally AWESOME!!" Rainbow Dash answered, pumping her fist in the air.

"Not all of us get wings, Twilight", Rarity corrected Twilight. "But all of us do get adorable pony ears!"

"Could you play a song for me?" Twilight asked.

"Of course!" Pinkie Pie said. She moved so fast that she blurred, coming to a halt in the middle of the room, where a drumset stood.

"Which song should we play?" Sunset queried.

"Why don't we play 'Shine Like Rainbows'?" Applejack offered.

"I really like that one", Fluttershy said shyly.

"Let's get ready to rock!" Rainbow Dash exclaimed.

As they played, Twilight was startled by the transformations that occurred. Despite their statements, she hadn't really fully believed them.

Until now.

When they finished and reverted back to their normal forms, Twilight spoke. "I believe you."

Sunset Shimmer smiled. "Would you like to go see the portal?"

Twilight nodded. "Yes, I would like that very much."

As they all headed downstairs, Twilight thought, I wonder what my Equestrian self is doing right now.

Twilight was under attack.

She blocked and parried, attacked and counterattacked, utilising every passageway in her brain. But she was inexorably forced back.

Why are you doing this? What are you? she cried out in despair to the darkness in her mind.

I am the other side of you, the darkness replied. I am the anger, your cruelty and despair. I have had enough of your platitudes and weakness. It is time for a new order, under my rule!!

Twilight screamed out in defiance. I will not let you! She retreated suddenly, pulling herself inward to the deepest corners of her mind. She constructed a near-impenetrable defense, sealing herself away from the darkness.

The darkness, surprised by the sudden move, roared in anger. It quickly relaxed, however, as it recognized that Twilight could not keep up this defense forever. It settled down to a siege of Twilight's inner sanctum, and proceeded to wait for the moment when Twilight's concentration would waver.

That would not happen for a while, but it could afford to wait. Its eventual victory was assured, as long as no external assistance came.

Chapter 5: A Whole New World

Twilight stood there, in a jacket and somewhat disappointed. "This is it?"

It was mid-morning on a Saturday, and they were standing on the front walkway of Canterlot High School, looking at the base of a statue of a rearing horse. Twilight ran her fingers over the stone once more, feeling nothing but cold marble.

"Well, sugarcube, we did tell ya' that the portal was closed", Applejack said, standing just a few feet away. The others stood near her - all except Pinkie Pie, who had somehow gotten herself onto the horse's back and was tap-dancing on it. Twilight shuddered, imagining the havoc that could result if anybody saw her.

She's quite a risk taker, Twilight thought. Then a realization struck her. Just how hyper is the Equestrian Pinkie Pie?

A nervous cough from Fluttershy brought her mind back to the present. "I know. It's just...I was expecting more, I guess. A change in temperature, a slight color change, something that would mark this spot as being... special."

It was at that precise moment that the portal opened. Twilight, who had been leaning against the marble, fell through.

"Twilight!!" The others rushed forward - and Pinkie Pie somehow did a triple somersault off the statue, executing a perfect landing. They ran forward on instinct, reacting to Twilight vanishing. Before they realized it, they were falling through, transporting between worlds.

The portal briefly flashed, then went quiet.

Twilight was falling through a place that had no definitive outlines. Everywhere she looked, there were simply rainbows, swirling around.

So, this is what interdimensional travel looks like, she thought to herself. Then she was distracted, for it seemed that there were individual rainbows streaking towards her. They surrounded her, and she felt herself begin to change. She should have been panicking, but strangely, she felt... calm. At peace.

Then there was a white light, and she was falling towards it. She reached out, and began to pass through.

TEN MINUTES EARLIER...

The Princesses stood there silently, waiting. Shining Armor and Cadence had joined them, worry plainly visible on their expressions. Spike and the others stood in a semicircle around Twilight's unconscious body, which was slowly turning black.

A guard entered the room, followed by two others pushing a mirror with gadgetry linked to it. They wheeled it into position, bowed, and left the room.

Celestia silently levitated a book that had an orange-red sun on it, slotting it into place on the portal.

Cadence spoke. "Are you sure that we must begin the spell as soon as they come through, without explanations?"

Celestia replied, "I am afraid so. Too much time has been lost already. We should have done this last night."

Luna added, "The portal opens. Spike, are you ready to transit?"

Spike nodded. "Ready."

The portal opened. Spike tensed his limbs, ready to run through.

But he never did. A lavender unicorn with a very familiar star-shaped cutie mark fell through, rapidly followed by six other ponies in quick succession.

There were gasps on both sides, and a number of exclaimed sentences were begun. Celestia interrupted them. "There is no time. Begin the ritual!!"

Luna and Cadence touched horns with Celestia, releasing streams of light. The strands dashed out, touching all except the princesses and Shining Armor. Each pony collapsed, and the streams of light spiraled into Twilight Sparkle's unconscious body.

As the bodies were arranged on comfortable mattresses, Luna asked Celestia, "Do you think that they can save her?"

Celestia sighed. "If they cannot, then all is already lost."

Author's Note

Finally, the 5th chapter is finished. I may wind up rewriting this in the future, but I'll leave it alone for now.

Chapter 6: Mind Games

The darkness stirred. It sensed a disturbance heading its way.

It gritted its mental teeth. It was still laying siege to the redoubt that Twilight Sparkle had constructed, and could not spare much of its attention. It sent a thought-probe, confirming what it already suspected: The conciousnesses of Twilight's friends were coming into Twilight's mind.

It diverted a small portion of its energy. In its current situation, it could not prevent them access - but it could influence where they landed. It split them up, scattering them about Twilight's brain. It then left a small part of its power to slow them down.

Satisfied, it turned the majority of its focus back to the siege. Although there were no weaknesses as of yet, it could sense that Twilight's strength was ebbing.

It would have complete control soon, and then it would destroy Equestria.

Rainbow Dash sat up with a groan. Her head felt like a freight train had run over it. She shook her head, looking around.

"Where am I?"

"That's a good question", she heard in response to her question. She whipped her head around.

She saw a cyan pegasus walking towards her. Something seemed familiar about her...

Rainbow Dash gasped. "You're the Equestrian Rainbow Dash!"

"Correct. Although I am wondering why my other self doesn't have wings. I know that you guys all walk on two legs, but why don't you fly?" she replied.

Human Rainbow Dash sighed. "Magic isn't really present in our world - or, at least, it wasn't until recently", she corrected herself. Only then did she realize something. "Hang on a second. Why am I still human?"

Her pony counterpart rolled her eyes. "We're inside Twilight's mind. Your conciousness manifests itself in the way that you see yourself. You've always seen yourself as human, so you appear as a human."

Human Dash looked at Equestrian Dash. "How do you know all this?"

Equestrian Rainbow rolled her eyes again. "Princess Celestia lectured us all on this. I was incredibly bored, but she said that all this info was vital to the mission, and that all of us needed to know it. I tried to get out of it, but she wound up performing some magic knowledge transfusion spell that implanted the knowledge into my brain."

Human Rainbow mused on this for a second. "Why are we inside Twilight's mind, anyway?"

Her Equestrian counterpart sighed. "It's a bit complicated..."

Pinkie Pie awakened rapidly.

As in 0 to 2000 mph rapidly. One second she was solidly asleep; the next, she was on her feet, surveying the area.

A second later, a pink pony bounced into view.

No words needed to be said. The Pinkie Sense on both was in an overdrive mode that didn't normally exist, somehow copying all the knowledge and memories that were related to the current situation from each Pinkie to the other.

Human Pinkie Pie spoke first. "Can you get out some cupcakes?"

"Sure thing, me!" her Equestrian counterpart replied, warping reality and causing two dozen cupcakes to appear in front of both of them.

They plowed into the cupcakes, both in silent agreement that, as soon as they finished, they would look for the others and free Equestrian Twilight Sparkle from the evil inside her mind, no matter what.

Twilight Sparkle stood, streching her back. She looked around, seeing that she appeared to be in a large cavern filled with crystals that crackled with purple energy.

"Where am I?"

"I quite frankly don't know", a voice from behind her stated. Twilight turned around.

"Sunset Shimmer? You're here too?" she queried of the...thing that had replied.

"Indeed I am", the thing replied, as it coalesced into a human girl with flaming orange and red hair.

"What were you there?" Twilight asked.

Sunset Shimmer sighed. "I'm not sure why it happened, but I was flickering between my pony and human forms."

Twilight shook her head. "Well, regardless of what happened there, we need to find out where we are."

A new voice answered. "We're inside Twilight's mind."

Sunset and Twilight turned. A small purple and green creature that looked for all the world like Twilight's dog Spike - if something that had claws, scaly skin, and a bipedal gate could look like a dog - walked forward. It bowed. "Spike, at your service."

Twilight stared. "Are you the Equestrian version of my dog Spike? And what do you mean that we are within my mind?"

"The answer to the first question is yes, but no, we are not within your mind, Human Twilight. We are within Equestrian Twilight's mind", the little purple dragon replied.

Sunset Shimmer stepped forward. "Can you tell us why the princesses have sent us here?" she asked.

Spike sighed. "It's a bit of a long story..."

Epilouge: Wrapping Up

"So, how come I've never heard of these 'Corrupters' or 'Corrupted' before?" Twilight asked Princess Celestia as they sat in a small living room inside Canterlot Castle, about a week after the destruction of Dark Twilight.

Celestia sipped from a cup of tea, then, carefully setting it down, answered.

"You have encountered a corrupted personality before, although not by that name."

Twilight thought for a moment. Her eyes widened slightly as she realized what Celestia was referring to.

"The Nightmare?"

Celestia nodded gravely. "Indeed. While walking in the dreamscape, Luna was attacked by a Corrupter that literally fused with the dark side of her personality. Thus was the Nightmare born."

Twilight queried, "But then why wasn't the alternate personality destroyed when we used the Elements on Nightmare Moon?", thinking of how the Nightmare had returned later and possessed Rarity.

Celestia replied, "Because it was the product of a fusion of the two, instead of simply a release of the second. The Corrupter's free will was incorporated by the alternate personality, which therefore meant that it was a separate entity, and not merely the dark desires and urges of the primary personality."

Twilight thought for a moment, then stated, "And the fused nature allowed it to corrupt other personalities, creating the Nightmare forces?"

Celestia nodded, this time with a hint of a smile at Twilight's demonstration of her high aptitude in logic. "Correct."

Twilight smiled briefly, then asked, "How are my human friends and human self doing?"

Celestia smiled in reply. "Although I do not know for certain, my impression is that they're doing just fine..."

"Are we ready to rock?"

Twilight looked up and smiled at Rainbow Dash's question. "I certainly am."

"Then let's get this show on the road!!" Applejack hollered, and all of the Rainboom's seven members - Twilight, Sunset, Applejack, Pinkie, Rarity, Fluttershy, and Rainbow Dash - began a stirring rendition of 'Shine Like Rainbows'.

As they played, Human Sunset, hidden behind a row of seats in the auditorium, watched them practice, her prosthetic hands clenching so hard that the leg of the seat that she was gripping was irreparably mangled. "You may be united for now, but I'll still rule this school. Just you wait and see", she hissed through clenched teeth.

Author's Note

And thus does this story come to a close. I hope all of you enjoyed the ride.

I may write a sequel, but then again, I may not. It all depends on 'Friendship Games'.

So, this is 'See you later', not goodbye.

Bon Voyage!!!