Rainbow Dash snored loudly as she lay peacefully on top of a cloud. That peaceful sleep was soon disturbed by a pony who was bouncing joyfully back home and was giggling madly.
Rainbow Dash opened up one eye and looked down to see her friend bouncing by. She noticed that she was carrying a white bag in her mouth. Rainbow Dash became suspicious as to what was inside the bag and swooped down in front of her friend. She was hoping that maybe Pinkie Pie had bought some candy or muffins, and that she might be interested in sharing something with her. "Hey Pinkie, what do you have in the bag?" Rainbow asked.
Pinkie Pie put the bag down and started giggling madly again. "Twilight Sparkle diagnosed me with mania and she wanted to go about a more natural and safer approach by treating me with Lithium. Twilight told me that Lithium can be found in natural spring water and the dose she is giving me would be considered very low among many other ponies who work with medicine. These capsules are even veggie based and everything is super duper natural and safe here. She said that I have been so happy and high that one day I could possibly crash and something natural that could stabilize my mood would prevent me from becoming Pinkamina Diane Pie again.
Rainbow Dash cocked an eye brow. "Lithium," she said. "Does this mean you're going to be uh, different now?"
Pinkie Pie shook her head no. "I'll still be the old cheerful Pinkie Pie, but I just won't be as crazy! Twilight Sparkle said that if I don't take these pills, then the pillow room police will come and take me away and I'll be bouncing all over the fluffy pillowed walls in my strait jacket!"
Rainbow Dash shrugged. "I'm kind of bored today. Would you like to go and pull some pranks on our friends?"
Pinkie Pie shook her head no again and said, "Twilight said I can't do anything too crazy at the moment until my body starts to absorb the medicine, but I'm sure we can do some pranking when I am fully stabilized! She said I'd need to wait at least a week or so before I can do anything fun."
Rainbow Dash sighed and said, "Well I guess we can wait until you're uh, stabilized. I will come back and check on you in a week."
Pinkie Pie grabbed the bag with her mouth and began to bounce away from Rainbow Dash. She couldn't stop giggling.
Rainbow Dash scratched her head with her hoof and said, "Lithium. I hope this means she'll still be fun."
After a week of waiting, Rainbow Dash walked into Sugar Cube Corner. She was surprised to see Pinkie Pie calmly putting some baked goods away. She studied her very carefully as if waiting for that moment Pinkie Pie would do something crazy and funny. Rainbow trotted up to the counter and said, "Hey Pinks, are you all ready to have some fun today?"
Pinkie Pie took out a batch of freshly baked cookies. "I'm sorry, but I just have to put these away and clean up a bit. I'll be done shortly. Would you like a cupcake?" Pinkie Pie asked.
Rainbow Dash raised an eye brow and said, "Are you asking me if I want a cup cake Pinkie?"
Pinkie Pie look confused. "What do you mean by that Dashie?"
"Well, you normally don't calmly ask questions like that! You just shove cupcakes and apples into our mouths because you're an impulsive pony! What has gotten into you Pinkie Pie? You're starting to scare me!"
Pinkie Pie sunk low to the ground. "I'm so sorry Dashie, Twilight just wants me to be safe so I don't crash in the future and become a possible danger to myself. How would you like me to behave?"
"Like this!" Rainbow Dash said as she grabbed the cupcake from Pinkie Pie's hoof and shoved it into her mouth.
Pinkie Pie gave a forced grin with the cupcake inside her mouth and then swallowed. "I-I-I just don't feel the need to act out my thoughts so quickly anymore Dashie."
Rainbow Dash tapped on the counter impatiently with her hoof. "Well," she said.
"Well what?" Pinkie Pie asked.
"You just had a specially made Pinkie Pie cupcake! It has been roughly ten seconds and you still are not bouncing off the walls. You are super sensitive to sugar and those cupcakes are sweeter than any other treat you make here! Your job and destiny in life is to make ponies smile and be happy and I am not experiencing either of those right now."
Pinkie Pie gulped and said, "Dashie, I think sugar makes me more prone to my mania out breaks. I may just be mellowing out a bit, but I'm still full of laughter and smiles though!" Pinkie Pie suddenly bent down and pulled out a fake turtle. She placed it on the counter and squeezed the pump. A spew of water came out of the turtles mouth and splashed against Rainbow Dash's face. "See Rainbow Dash! I saved one of our most favorite prank of all time!"
Rainbow Dash put her hoof against her head and sighed.
Pinkie Pie began to panic. She bent down again and started throwing random things that she found for their special day together. Harmonicas, party horns, rubber chickens, the dribble glass, fake snakes in a can, and more. Pinkie Pie took the can of snakes and opened it up in Rainbow Dash's face. Confetti and plastic snakes popped out and got stuck in Rainbow Dash's mane. Pinkie Pie smiled awkwardly in hopes that she might earn a smile from one of her best friends.
Rainbow Dash simply tapped against the counter with her one hoof as she held her head in boredom with her other hoof. "Boring!" Rainbow said. "Pinkie, you lost your spunk and you're just not the same. I don't even want to hang out with you until you're back to the crazy, random, and fun Pinkie Pie that I once knew and loved. I want you to stop taking those Lithium pills!"
Tears began to well up in Pinkie Pie's eyes. "I-I-I just want to please and make you smile Dashie, but Twilight Sparkle said I might be a danger to myself if I happen to crash again and my mane and tail flattens out! I'm so sorry I failed to make you smile." Pinkie Pie suddenly left the bakery and ran upstairs crying.
Rainbow Dash sighed and looked around the counter. There she saw a bottle of Pinkie Pie's Lithium pills. Suddenly, a rather sinister grin crept up on the face of Rainbow Dash. Rainbow took the pills from the counter and hurried out the door. She had the greatest prank she was about to pull off in her mind.