An Unknowable Destiny

It's no fun when Rainbow Dash is bored. Trust me: I've had a firsthoof experience.

'Ugh...' thought Rainbow Dash, 'I'm so bored! Twilight went to the Crystal Empire to visit her brother, Princess Cadence and Flurryheart, Applejack has to work, Pinkie Pie is helping Fluttershy prepare a birthday part for Angel Bunny, Rarity went gem hunting with Spike, and  Starlight is reading a ton of boring egghead books!'

She looked down on Ponyville from her cloud to see if there was anypony not doing anything so she could have fun. All Rainbow could see were ponies working or doing something else that was boring.

'Why is everypony so busy?' she thought.

"La la la!" heard Rainbow, "Just relaxing!"

Rainbow looked around and saw a brown unicorn. She had a green mane with brown stripes in it and some sort of orange horn.

'Perfect!' thought Rainbow, 'Somepony not doing anything!'

She dove off of her cloud and landed in front of the unicorn.

"Whoa!" when the unicorn in surprise.

"Hey there!" said Rainbow, "What's you're name?"

"Um, my name is Razor Blade."

"Why do you have an orange horn?"

"I'm not quite sure, it's just been there since I got my cutie mark."

"Wait, so you haven't always been a unicorn?"

"I like to call myself a unicron."

"That's awesome!" said Rainbow Dash, "Do you wanna hang out? All of friends are doing boring stuff."

"Uh, sure. I guess so." said Razor nervously, "What do you want to do?"

Rainbow grinned, "I have just the thing!"

"Rainbow, I think this is a really bad idea!" said Razor, "Maybe we should do something else!"

"No way!" said Rainbow, "This gonna be awesome!"

"Are you sure it's safe to do a Sonic Rainboom while I'm on you're back? I've never flown that fast before!"

"Of course it's saf- Wait, did you say you've flown before?"

"Yeah. My horn sometimes changes into a pair of wings..."

"That's awesome!!!" said Rainbow, "Now, you might want to hold on tight!"

Razor wrapped her hooves around Rainbow so she wouldn't fall off.

'Why didn't I just say I was busy?' she thought.

Rainbow flew up higher and then switched into a diving position.

"Here we go!"

Rainbow dove towards the ground super fast.

"Rainbow!" said Razor in a panicked voice, "This is a really bad idea!"

"Why wold you say that?" asked Rainbow.

"I have no control over my magic and it does super random things! Like right now, my horn's lighting up and I don't know what it's going to do!"

"That would be awesome!" yelled Rainbow.

Rainbow accelerated to maximum speed and turned up from her dive, resulting in a Sonic Rainboom.

"This is terrifying!" Razor yelled.

"This is awesome!" Rainbow yelled.

"How do you stop?"

"I run out of speed!"

"What if you don't?"

"How would that be possible?"

"Magic!"

Rainbow glanced back and saw that Razor's horn was lit up, and realized that she wasn't losing any speed.

"Hold on tight!" she yelled to Razor, "I can't steer anymore!"

Razor gripped tighter onto Rainbow with her hooves as Rainbow flew uncontrollably.

"I'm so glad that we could have a peaceful and normal day of activities!" said Shining Armour.

"Yes, it is very nice to not have to worry about the world ending!" said Princess Cadence.

"Tell me about it!" said Twilight Sparkle.

The three of them laughed as they walked though the Crystal Empire.

"Everypony, look!" called a Crystal pony, "There's something in the sky!"

Everypony that heard the call looked up into the sky and saw a orangey-rainbow blur whizzing around.

"What is that?" asked Cadence.

"It looks like Rainbow Dash going super fast!" said Twilight, "We need to see what's wrong!'

She and Cadence took off into the sky towards Rainbow (and Razor, though they didn't know it).

"Okay, maybe you were right about this being a bad idea!" said Rainbow to Razor, "But this is really cool!"

"Who's that?" asked Razor as Twilight and Cadence approached.

"I think it's Twilight and Princess Cadence! We flew all the way to the Crystal Empire?"

"Rainbow! What are you doing?" called Twilight.

"Flying uncontrollably at  an uncontrollable speed! Isn't that obvious?"

"But how?" asked Cadence.

"That would be my fault!" said Razor, "Well, technically my horn's fault!"

"Wait, Rainbow is someone with you?"

"Yeah! Her name's Razor Blade! And-"

But Rainbow cut off as Razor suddenly fell off of her and went skyrocketing. Rainbow immediate;y slowed down to a normal speed and regained control.

"Phew! I thought that I would be flying like that forever! Wait, where's Razor?"

"I think she let go of you!" said Twilight in a panicked voice, "She went flying upward from all the momentum!"

"What?" said Rainbow, "Can't you guys find her before she starts falling back down?"

"I can't see anything because the sun's too bright!" said Cadence.

"If she falls from this height with all that added height, she's sure to take some serious damage!" said Twilight.

"I have never taken any real damage!" yelled Razor as she fell back down.

Twilight quickly activated her magic so she could levitate Razor and stop her from falling.

"Did you get her?" asked Cadence nervously.

"I don't know!" said Twilight.

"You didn't," came a reply from below them, "But I'm fine!"

"What in Equestria do you mean that you're fine?" asked Twilight.

Razor suddenly appeared on Rainbow's back.

"Magic does have some advantages."

"What th-?" asked a shocked Rainbow.

"Maybe we should talk about what happened in the castle instead of in the air." suggested Cadence.

"That would probably be a good idea." said Twilight.