Twilight looked at her reflection in the mirror. "Sunny..?" She asked it. "Sun..." She fell, and started crying. Celestia sighed, before levitating the young unicorn, and bringing her towards her. "Princess, you need to bring her back!"

"I'm afraid.. I can't do that darling.." She placed Twilight down, before frowning. "She's gone now."

"Will she ever come back..?" Twilight asked.

"Maybe one day." Celestia's horn started to glow. "Forgive me.. My Faithful Student." Celestia pushed her horn to Twilights, before a spark lit the room.

10 YEARS LATER

Sunset Shimmer stood outside, in front of the portal on the school grounds. "Today's the day, I get to see Twilight Sparkle." She smiled. "I've had more than enough time to think." Sunset Shimmer stepped through, and re awoke in her pony form. "Wait.. Where, am I?" She asked herself. "Oh no... Don't tell me." She looked around the room. "This is the wrong castle. What happened.."

"Luna." She heard the all too familiar voice, and teleported somewhere safe, behind some boxes. "The portal has already opened, my dear sister. With it, Sunset Shimmer is able to return."

Luna? Wasn't she banished to the moon? Did she return already..? Maybe that explains why she became a vice principle.. Sunset thought to herself.

"Yes, sister. I shall make sure that the others don't know." Sunset knew that the voice matched the one of vice-principle Luna, which explained her return.

"If Twilight sees the mirror, her memory might come back to her, and I'm afraid she can't have those memories. She cannot know of Sunset Shimmer, until she returns. The young princess may be in danger if we act selfishly."

Sunset was heart broken, here she was coming to see her friend Twilight, and her memory had been erased. Not only that, but Twilight was a princess now too. Now she was angry. Her best friend, who was weaker then her from the beginning, was a princess.

She heard the two princesses leave, and then she thought of a plan. She would steal Twilights crown. The last time she came through this mirror, it was to do a check up without anyone knowing. She knew Twilight was connected to the Element of Magic, from the Elements of Harmony. Sunset had studied this a long time ago.

Suddenly, she had an idea. She wanted to be a princess, and she wanted it to be done her way. She'd take that crown, and use it for herself. If you brought an element of harmony into another world, it would get stronger, and loose balance, making the current user more and more powerful. This was her plan. She'd steal the crown. She pulled out her robe from her saddle bag, and put it on. "Alright."

Twilight was sound asleep in her bed, Element of Harmony, and crown next to her. She didn't know that there was a pony running through the halls, to come and steal it. The door opened, and in walked Sunset Shimmer. Levitating the crown, she brought it towards her, and knocked over a lamp. Quickly, she caught it, and sighed. Replacing Twilights crown with a fake model she threw together, she turned to walk out, but tripped over Spikes tail.

"Whoa!" she called before she hit the ground.

"Huh?!" Spike asked, getting up. Twilight yawned and got up, before looking at the pony who had just gotten up.

"My crown, she's got my crown!" Twilight said. Sunset bolted out the door. "Stop, Thief!" Twilight ran out, awaking her friends. "She's got my crown." It was now a full blown chase.

Sunset was surprised when Twilight appeared a good 10 feet in front of her. Charging her own magic, she teleported before she hit Twilight, making her robe come off. Turning, she smirked, before she kept running. The chase got really intense, with Twilight now on her tail once again. Twilight pounced, and both girls went tumbling, just like old times. The crown flew out, and went flying through the portal, making the 6 ponies gasp.

"What did you do to my crown?!" Sunset was heart broken, but still smirked.

"Sorry it ha to be this way." She teleported in front of the mirror. "Princess!" She jumped through.

"Who was that?" Fluttershy asked.

Celestia honestly regretted everything now. "Sunset Shimmer, a former student of mine." She had to lie to her most faithful student, and it hurt. "She began her studies with me, not long before Twilight did.. But when she didn't get what she wanted, as quickly as she liked, she left. I hoped that Sunset Shimmer would one day return, to continue her studies.. But it seems, this is not the case."

They walked to the mirror, all together.

"This is no ordinary mirror." Luna said. "It is a gate way to another world. The inhabitants of this world, are now in great danger.."

"Twilight, retrieve your crown, without it, the other Elements won't work, and Equestria is without a great mean of defense!" Cadance stressed.

Sunset was very content with herself. She had gotten the crown, and that's all that mattered. "Where.. Where's the crown?!" She asked, looking around as she stepping out of the portal. "Oh no.." She watched as Fluttleshy gave the crown to Principle Celestia. That was it, she went inside, and things were about to get serious.

After giving Fluttershy a good yelling, she was stopped by a purple colored girl. Of course, that didn't bother her too much, now that she knew it was Twilight. She had always been a goody two shoes, and no one knew more then Sunset. "Should of known Princess Celestia would send her prized pupil here to steal my crown." She smirked.

"It's MY crown." Twilight glared.

"Whatever. Pop Quiz, what happens when you bring an Element of Harmony into another world?" There was silence. "You don't know?! Ha! But, what are the chances the Princess would of found someone as smart as me when I left. Pretty pathetic that you were the best she could do." Spike barked. "Oh, I'd keep your little mutt down. She pet his chin. "Don't want him to be.. Oh, taken away."

"Is that a threat?" Spike growled.

"Oh, of course not." Sunset said sarcastically. She then walked away, feeling so proud of herself.

It was the night of the dance, and everything was going according to plan. Sunset was waiting outside for the crown, that would soon belong to her. Snips and Snails made it outside with Spike, before she swung the hammer up. She knew it would just pass through like everything else, but Twilight didn't.

"Give me the crown, or the portal back home is gone forever." She smirked, ready to hit the portal.

"... No." Twilight said seriously

"WHAT?!" Sunset was taken back. "Equestria, your friends, doesn't that mean anything to you?!"

"Equestria will survive without my element, but this place won't." Sunset sighed, knowing that she might of been defeated.

"Fine, you win." She dropped the hammer on the ground. Everyone gathered around Twilight, saying how awesome she was, and how great she handled things. "Oh yeah, she's just so perfect, isn't she?! Get her!"