It started when Rainbow Flash flew into Ponyville, triggering Pinkie Pie's mysterious Pinkie Sense. Without warning, that pink wonder popped out of Rainbow Dash's mane to grab Rainbow Flash and pull her into Rainbow's mane. The two fell down from above the camera as they reappeared inside Sugarcube Corner to find everypony in town present for a party, whether they were doing something else that morning and ready or not. Lyra and Bon Bon really weren't prepared to be teleported into a Pinkie Pie party, but Big Mac made sure to stand in front of them and give the two some privacy as they stopped eskimo-kissing and backed away from each other with a blush.

Discord was ready for a party, and he was ready to see how long all these slightly-brainwashed ponies could go before realizing what the little prank he'd played upon them was.

Rarity blinked in surprise, her magic dropping the sewing supplies she'd left behind in her house. She wasn't ready for a party either.

Twilight Sparkle, who'd been in a completely different part of the world, wasn't ready for a party either.

But as soon as Pinkie started the music and announced who the guest of honour and new pony in Ponyville was, and Rainbow Dash flew in through the open window to stand by her sister, everypony was ready to par-tay!

"Hi, I'm Pinkie Pie!" Pinkie Pie beamed. "Are you ready for some fun?"

"Always!" Rainbow Flash flared out her wings as the rest of Pinkie Pie's friends gathered around.

"Great! We've got pin the tail on the pony, bobbing for Applejack's apples, and music!" Pinkie told her.

And she was right. The music that was playing right now... It was the greatest music of all time.

"What's your name, dear?" Rarity asked.

"I'm Rainbow Dash's twin sister, Rainbow Flash!" Rainbow Flash told her.

"You have a TWIN?!" Pinkie Pie gasped. "Dashie, why didn't you tell me?"

Rainbow Dash smiled and prepared to say something, only to find that she had absolutely no idea what to say. "Uh... It never came up until now?"

"That's so unrealistic." Twilight said. "Surely if you'd always had a sibling all along, you would have mentioned her at least once by now."

Everypony stared at her. Especially Spike.

Twilight ignored this. "Rainbow Dash, are you playing a prank on us?"

"No way! This is my real sister!" Rainbow Dash insisted.

"Yeah!" Rainbow Flash agreed.

"Just look at her, Twilight!" Pinkie Pie, insisted. "She's white and she's got rainbows on her wings, in her hair, and on her eyes! And her rainbow mane looks just like Rainbow Dash's except the front part is longer and the top part is spiky and the back part is a ponytail! She's even rainbowier than Rainbow Dash! How can they NOT be related?"

"Look at my Cutie Mark," Rainbow Flash offered, turning around and shoving her hips in Twilight's face, tail gently guiding the blushing Alicorn's neck closer to give her a better view and make her see. "It's a sun, only coloured in by a rainbow-coloured spiral!"

Twilight teleported away to safety, and smiled nervously. "You're right, I'm just being silly. Sorry, I was up all night yesterday working on my speech for MagicCon 5075."

"MagicCon, the biggest magic convention ever?" Rainbow Flash gasped. "I can't believe you get to give a speech there! You're so lucky!"

"You like magic?" Twilight asked.

"I love magic! And flying and music and animals and food and everything else ever!" Rainbow Flash smiled. "I wish I could do magic. Then all those magic books I read as a filly would have mattered."

"My sister's a total bookworm and magic nerd! You two will get along great." Rainbow Dash said.

"Well, I know one way you can do magic." Twilight looked at her wings. "I became an Alicorn once, but I don't know how easy it'll be for you to do the same."

"I'm sure I'll find a way to do magic some day soon," Rainbow Flash smiled. "Want to read books with me tomorrow?"

"I've got a speech to prepare in just two days-"

"I can help you do it, if we read together first." Rainbow Flash offered.

"Sounds great!" Twilight smiled. "I don't know why, but I already feel like I can trust you with anything. I know I've only known you for a couple of minutes, but it feels like I've known you for longer than that. Something like... a couple of days."

"I just have that effect on people," Flash smiled, and looked at Fluttershy. "Who's that cutie?"

Fluttershy blushed at first, before remembering that she had Angel Bunny on her head. "This is Angel Bunny, and he likes carrots." She smiled.

"Not him..." Rainbow Flash stared deeply into Fluttershy's eyes, and winked. "Who's this cutie, right in front of me?"

Fluttershy's blush turned her whole face red. "Ummm..." Quietly, she whispered, "I'm Fluttershy."

"What was that?" Rainbow Flash asked, growing closer, sidling up to the mare and wrapping her rainbow tail around the yellow cutie. "I didn't hear you."

"I'm fluttershy"

"I can't hear you!" Rainbow Flash turned her face so her ear was pointed at the yellow mare, she smiled at her from the side, and their cheeks touched.

"imfluttershy" She whispered.

"Louder," Rainbow Flash whispered softly into Fluttershy's ear.

The yellow Pegasus fainted like a goat, and everypony laughed. But Discord laughed the hardest.

"Oh my, Rainbow Dash, your sister certainly is bold." Rarity blushed.

"Bold and brash!" Rainbow Flash boasted. "That's Rainbow Flash!"

"She's always looking for somepony to be her special somepony." Rainbow told her friends.

"Just keep her away from mah brother, Big Mac's finally got something good goin' on with that Cheerilee feller."

"I thought he was dating Sugar Belle." said Twilight.

"That simply ghastly baker from Glimmer's dreadful town?" Rarity asked. "Did she and Big Mac ever meet, or share even a single line of conversation?"

"I'll never forget those awful muffins I had to eat because of her..." said Pinkie.

"Hey, she only sucked at baking because of Starlight Glimmer. Once we kicked her butt and sent her packing, we never heard from her again." Rainbow Dash reminded them.

"I'm glad she never came back for revenge," Twilight admitted. But then, something felt wrong. "Wait a second, who's Glimmer?

Discord teleported outside of Sugarcube Corner so he could chuckle malevolently. "Who, indeed?" He chuckled. He was always waiting for his time to get his revenge for that time she banished him. That overpowered dolt would ruin Discord's fun far too quickly, so he decided a world where the average superhero or supervillain's powers far outranked and eclipsed hers would be a much more interesting place to send her. Plus, that stupid school made everything too boring. Discord wanted to see the ponies spend time with Rainbow Flash, not some dumb Griffon or Dragon whelp nopony gave a flying feather about.

"I have no idea what any of you are talking about." Rainbow Flash admitted.

Everypony got a headache for a second. And then Spike spoke. "You guys must have been having weird dreams again or something, because Starlight Glimmer isn't real, and she never was. She's of the villains Matter-Horn fought in last week's issue of Power Ponies."

"But if Glimmer never existed, then who's Sugar Belle?" Twilight wondered.

"Nopony, none of them existed." Applejack explained.

"Some of them probably exist somewhere, since I remember throwing a party with Party Favor one time." said Pinkie. So maybe we all just took our memories of them and made up the whole dream?"

"Makes sense to me." said Twilight. "Spike, out of curiousity, what happened in the issue of Power Ponies Glimmer was in recently?"

"She and the Golly Goblin teamed up to try and take down the Power Ponies and blow up the Hero School." Spike explained.

"That school is such a silly direction for the writers to take, all for the sake of trying to give unnecessary new one-note characters some unearned screentime," said Rarity. "I know the Power Ponies have proven themselves to be heroes in the past, but it takes more than heroism to run an effective school. You can't just be good at something and expect others to copy you, you need to be good at teaching and helping your students understand the subject matter."

Everyone blinked in surprise.

Rarity realized her mistake and blushed.

Spike grinned. "You like Power Ponies, don't you, Rarity?"

"Well, I... I really liked that time when we got sucked into their comic, so sometimes, I... do it again when nopony's around." Rarity admitted.

"You guys got sucked into a comic once?" Rainbow Flash gasped. "Aw man, you guys have the coolest lives! I should have moved in with my sister sooner!"

Rainbow remembered something. "Oh, that's why I didn't remember you living with me until now!"

"I've lived with you before, genius!" Rainbow Flash laughed. "And now, I'm living with you again!"

"Oh, Rainbow Dash, you really are a silly pony." said Rarity.

Everypony laughed.