“Alright, one drop of potassium.” Twilight Sparkle instructed Spike who used a pipette to extract the potassium, holding it over the flask of bubbling liquid under a bunsen burner.

Twilight stood over her assistant, wearing a lab coat and safety goggles with her mane bundled in a neat bun. The pipette got closer to the flask, squeezing it slowly between his claws the baby dragon was sweating bullets next to Twilight. A single drop of potassium fell into the mixture, the bubbling intensified from the chemical reaction and it was glowing brightly from the heat. “Whew…” Spike wiped the seat off his forehead scales, giving a thumbs up.

“Good job, Spike. Now all we need is for this to remain undisturbed, it’s still highly volatile.” She warned, lowering the heat on the bunsen burner. And like everything that can go wrong with this, Rainbow Dash burst through the door. “Huh?” The flask shook and bubbled even more, colours swirling around inside. Thinking quickly she encased the flask with a magic bubble as it detonated inside with a blinding flash of light.

“Oh my gosh, sorry about your, uh, thing.” Rainbow Dash apologised, scratching the back of her head.

“That’s fine, why the hurry?” Twilight dusted the tabletop from the residue. “Not like you ever stop hurrying, but whatever.”

“I have a problem.”

“A problem? with what?”

Rainbow Dash paused awkwardly, being her she obviously mud thane forgotten how to say this. “Well…caring for-“

“Tank? He's at Fluttershy's since you were at the-”

“No. A mare who has the brain of a filly.” Rainbow Dash deadpanned.

Taking a moment to look at her speedy friend, Twilight turned to look at Spike and shared a confused stare before they both turned to Rainbow Dash. “Pardon?” She asked, removing her goggles in case they were impairing her hearing.

“I chose to look after Lightning Dust.”

“Woah woah slow down! Lightning Dust? The pegasus who’s a cockier version of you? Why on Equestria do you want to care for her after she almost killed us, your friends!” She exclaimed and threw her arms up, clearly never receiving the news.

Thankfully in cases like these, Rainbow Dash thought ahead for something at least, digging in her back pocket she pulled out the doctor’s diagnosis as well as Celestia’s letter she received this morning. “Just read these two.” She handed the two papers to Twilight, never before had the cyan pegasus looked so serious without bursting out into a headstrong rage.

Sighing she might as well, picking up the diagnosis first she paused at the Canterlot insignia on the top left corner. “This is the Canterlot Palace hospital wing, how did she-“

“Read it.” Rainbow Dash sternly told Twilight, almost like it was a command.

Not wanting to get on Rainbow Dash’s bad side, she read through the diagnosis, bringing it closer to read it again.
“Excuse me.” Putting the letter down she picked up her reading glasses, placing them over her muzzle before picking up the paper again. “Spike…go see Rarity or something, I need time alone.” She asked her number one assistant, levitating a few bits to him.

“Alright! Thanks!” He gave Twilight a thankful hug for getting the day off and ran out the door on his stubby legs after hopping off the stool he stood on to reach the table.

Once the door shut, Twilight slammed the paper down. “Please tell me this is a sick joke, because I’m not laughing.” She glared at Rainbow Dash. “I know she’s not the most popular for her attitude, but, this is rather excessive isn’t it?!”

“I’m not kidding around!” Rainbow Dash snapped back, picking up the paper and thrust it to Twilight’s face. “Does this look like something I’d joke about?!”

Taken aback by her friend’s sudden outburst, she adjusted her glasses to read it over again. Falling back on a chair with a hand to her forehead. “Wh-…How- Wha-” Stumbling with her words Twilight very rarely had a loss for words, an explanation would be the first thing out her, but to see her speechless was a rare occurrence many of the highest achieving unicorns would pay highly to see just to feel better about themselves. To distract herself she read Celestia’s letter thoroughly, putting it to the side and began rubbing her temples with a groan. “No dragons?”

“Yeah, she has a phobia of them now and she wants to meet you guys. So I came to warn you about Spike and anything dragon related as well as how to look after her.” Rainbow Dash explained.

“Well, try being how you are around Scootaloo.” Twilight answered. “Oh boy, the girls won’t believe this…”

“The dragon thing or the brain thing?”

“Both!”

“Oh crap, I need to get dinner but I dunno how to cook.” Rainbow Dash panicked after remembering that she has to actually also provide food for Lightning Dust.

“I’d recommend some takeout…and cooking classes” Twilight recommended, picking out a pamphlet for a Japonese fast food restaurant nearby. “They actually sell toppings for normal ramen separately if you’re worried about any allergies she might have.”

“Thanks Twi, please tell everypony else about this.”

“I will, though I might need to tell them at the same time at this weekend spa session Rarity booked for us.”

“Alright good idea, I’ll book Dust in.” Dash smiled, flying out the door with the same speed she came in.

————

“I see dead ponies.” The character on television spoke, Lightning Dust hid under a blanket in the evening lit room as the movie played.

“Dust I’m home!” Called out Rainbow Dash as she walked in holding two bags of takeout, placing them on the table. “Sorry I was out so long, so how- Dust, did you spend this whole time watching horror movies?”

Lightning Dust nodded slowly, staring down apologetically. Childish curiosity, a marvel of nature.

Rainbow Dash rolled her eyes, ruffling Lightning Dust’s mane. “It’s cool, at least you’re safe. So, hungry?”

“Yeah, what’s for dinner?”

“Ramen, was the only thing healthier than hayburgers that I could get for you.” The cyan pegasus held up the second bag. “What topping would you like?”

“Spicy!” Squealed Lightning Dust in reply, peppers it is.

One hearty meal later the moon hung high in the night sky, shining its gentle light upon all who see it. Both mares sat together on the couch watching some good horror films, though Lightning Dust did not seem too fond of Friday the 13th. “Popcorn?” Asked Rainbow Dash, holding out a bowl of warm popcorn in the middle of the third movie they were watching, The Fog.

“Yes please.” Gripping a handful of popcorn in her hand she shovelled the handful in her mouth, chewing thoroughly and swallowing.

“Jeeze you got an appetite.”

All Lightning Dust did was grin with a giggle before jumping at a giant spider in the film which roared at the unsuspecting ponies on screen. “No no no! Aw, he was my favourite character too…” She pouted.

Rainbow Dash glanced over to the clock, past her bedtime if she really was a foal. “Alright Dust, bedtime.”

“Awww!” Lightning Dust groaned in reply, putting on a face to convince her carer otherwise. “Pleaaaase?”

“No, bedtime.” The cyan pegasus sternly replied. “Healthy sleep means healthy wings, also I kinda signed you up for a spa treatment tomorrow that might help. My friends’ll be there too.”

Thinking about it for a second the filly minded mare stared at the television, she had to admit Rainbow Dash had a point and she did really want to meet her friends. She let off a small yawn. “Ok…” She gave up, walking to the bathroom to brush her teeth.

Once both mare's nightly rituals were complete, Lightning Dust lumbered over to the bed, flopping onto it in her pyjamas which consisted of a lightning streaked shirt and lightning streaked trousers. Rainbow Dash assisted in tucking her in, yawning herself before heading to the bedroom door. “Sleep well.” Rainbow Dash tiredly smiled.

“W-Wait! What if the giant insects come out the closet!” Lightning dust called out while pointing the closet, hiding her face beneath the covers with only her eyes poking out to pleadingly stare at her carer, who was face palming. “Please protect me from the monsters.” She whimpered.

Rolling her eyes she tucked herself in, shouldn’t be too long until the scaredy mare falls asleep. Lightning Dust now feeling safer, closed her eyes and fell asleep before they fully closed, must have been a heck of a morning she had before coming over. Seeing her chance, Rainbow Dash slowly slid towards the end of the bed but felt two arms wrap around her. Turning her head over she was met with the sight of Lightning Dust snuggling up against her, smiling blissfully. For whatever reason she could just not bring herself to pull away, even if she wished to.

“Alright, just this once…” Returning the gentle hug comfortingly the smile on Lightning Dust’s face grew wider, nuzzling against Rainbow Dash who awkwardly blushed. “Goodnight.” She smiled in return, adjusting herself for the shared embrace and closing her eyes.

Author's Note

I did not expect to end up writing a sisterly thing.