For those interested in the original version, have a Google Docs link.

Twilight Sparkle let out a huff. Surrounded by piles of books – not uncommon when she got on a research bender – Twilight put a hoof to her forehead and gently massaged her pounding head. She was frustrated with the pace of her research. Non-pegasus flight is so poorly documented. Maybe I should have asked Rarity about her experiences, so that I could maybe use those notes to help improve that stupid spell. No, Twilight, if it’s stupid and it works, it isn’t stupid.

“Alright, Twilight, let's take a look at research notes once more, OK?” she said to no one. Spike had gone out gem-hunting with Rarity again, this time packing a powerful dog whistle. He most likely wouldn't be back until dinner time.

She flipped her notebook back to the first page and began reading. “Goal: manipulate the wing-granting spell to make the wings more similar to pegasus wings, not butterfly wings. Pegasus wings are more capable of advanced flight, and therefore offer much greater utility.

The rustle of parchment accompanied the next page turn. “Notes so far: pegasus wings are feathered limbs, similar in structure to those of the many birds that populate Equestria. Flight is achieved through… wings occasionally molt to allow fresh feathers to grow… hovering is achieved through circular flapping motions… butterflies have a bobbing motion due to their simple wings… aerial maneuvers are impossible without the rotating joints of pegasus wings.”

Twilight set down her notebook and sighed. “But I need to know more about how a pegasus flies! How do they learn? When? How big do the wings need to be? Does size matter? Ugh!”

She went back to the shelves of the library and began searching for anything else related to flight. Though she was positive that nothing else on the shelves could possibly have any hint of flight on their pages, she looked anyway.

You looked everywhere, Twilight. You won't find anything new. These shelves are picked clean. Face it, you need more books. Physics books, aerial trick guides, advanced mathematics, flight journals, anything that could help.

“Hold up, what's this?” Twilight levitated a thin pocket manual out from between a book end and the Encyclopaedia of Flightless Birds. “The Wonderbolt's Training Manual? Why do I always find the strangest books in this library?”

She quickly flipped through its pages, only to find that it contained nothing but rules and procedures for conducting training sessions with the Wonderbolts.

“Well, that was no help at all. Maybe Rainbow Dash will be interested in it, though. Rainbow Dash... of course! Why didn't I think to ask her about flying?! She's the best flier in Ponyville.”

Twilight set down the manual on one of the many piles of books before walking out the front door. She locked it behind her, knowing that nopony would come to library on a Saturday. When she pulled the key out of the door, she heard a whoosh overhead and the branches above one of her windows were swaying slightly.

Funny, she thought, I don't remember feeling a gust of wind. Maybe I just frightened a bird or something.

Twilight walked towards Rainbow's practice field, scanning the skies for any sign of her colorful friend. It wasn't until Twilight reached the edge of the field that she even saw the rainbow contrails left behind from Rainbow Dash's flying. With effort, Twilight finally spotted the pegasus proper. Rainbow was trying various barrel rolls and spirals; not simple maneuvers, for sure, but not her usual tricks.

Twilight took a seat at the nearest bench, and tried her best to keep an eye on the rainbow-maned mare. If it was hard just to follow Rainbow, it was damn-near impossible to watch the movements of her wings. Twilight only caught brief glimpses of them when Rainbow Dash braked for hard turns or quick reversals.

Sweet Celestia, she's good. She's not even trying any of her signature tricks, and she's impressive, Twilight mused. She gave a soft smile. She doesn't even need to fly to be impressive.

“Hey, Twi!” shouted Rainbow in her raspy voice as she came in for a landing. “What's up? I usually don't see you outside of the library.”

“I wanted to come and see you fly. You really are quite the talented flier.”

“Ha. Of course I am. Winner of the Best Young Flier Competition, remember? I have the trophy to prove it. So is that all that brings you out here? I know you won't abandon your books all willy-nilly.”

“I actually need your help, Rainbow. I'm doing some research, and you're only one who can help me.”

“You need my help? With research?” asked Rainbow, voice dripping with skepticism. “Like, with books and beakers and stuff?”

“No, no, not at all. Do you remember that wing spell I used on Rarity when we all came to watch you at the Best Young Flier's Competition? Well, I've been trying to improve it, so that instead of butterfly wings, I get something more like pegasus wings. But I need a pegasus to help teach me about flight.”

“Sure! Anything for you, Twi,” said Rainbow enthusiastically.

“Alright, back to the library we go.”

“Race you there!”

“Rainbow!”

“Kidding. Kind of.”

Twilight got up and walked back, with Rainbow lazily flying next to her. Rainbow would occasionally do a loop or flip just to pass the time, but she would always cast a glance back to Twilight, who smiled at her friend's antics. It seemed that the closer they got to the library, the bigger or faster Rainbow would do a loop or flip. One particularly fancy loop that involved a spiral and several flips ended with Rainbow landing hooves-down on a balcony of the library. Twilight chuckled and opened the front door while Rainbow let herself through an open window just under the balcony.

“Wow, Twi. This place looks worse than when I crashed in here.”

“Sorry. Spike's out, and I'm busy with my research. I'm pretty sure that every book on flying or related magic is out on the floor here.”

Rainbow spotted the little book sitting on top of a stack. “Whoa! You actually have a copy of the Wonderbolt's Training Manual? I'm so jealous. Do you think I can borrow it? I mean, those Daring-Do books were awesome, and, well, I’m really hoping to get into the Wonderbolts someday...”

“Aw, you finally like reading! I’m so proud!” Twilight gushed. Rainbow hid her face as best as she could. Twilight continued, “And of course you can borrow it. It didn’t help me with my research at all, it's mostly rules about practice and stuff. It didn't have anything on how they fly.”

“Well, it is meant for pegasi trying to join, Twilight. No offense.”

“None taken. I kind of figured. So I was thinking that I could ask you about how pegasi fly, and then write down your answers. Does that sound alright?”

“Sure, fine by me.” Rainbow plopped down on a nearby cushion, sitting on her haunches. Twilight magicked her own cushion over and took a seat herself.

She bombarded Rainbow with every question that she still had unanswered. To the best of her ability, Rainbow answered. Some questions, like how she pulled off her tricks, were easy and got long-winded answers, complete with sound effects and color commentary. Others, like whether wing size matters, were met with a shrug and some guess-work.

As Twilight continued with her questions, she noticed that Rainbow was getting increasingly anxious. It wasn't until Rainbow finally spoke up that she realized something was really wrong.

“Twilight, you aren't asking the right questions,” Rainbow said in a low voice, completely uncharacteristic of her.

“What do you mean, I'm not asking the right questions? I asked how it feels to fly, and how to fly, and all of the details? What am I missing?”

“So much,” Rainbow muttered. She was blushing – evidenced by the purple tinge on her cheeks – and she kept her head down, looking almost as nervous as Fluttershy.

“Sorry, Dash, what did you say?”

“Nothing.”

“Are you alright?”

“No.”

“Maybe you're coming down with something,” commented Twilight, putting her hoof on Rainbow's forehead. Rainbow blushed even more at Twilight's touch. “You don't feel feverish, but you looked flushed. Are you sure you're feeling alright? That you aren't coming down with something? Is your wing still in pain, maybe?” Twilight placed her hoof gently on Rainbow’s wing, feeling for anything wrong and listening for any signs of pain.

Rainbow pushed Twilight’s hoof away. “No, no, my wing’s fine. I already have something, but it's not what you think,” she replied.

“Oh? What is it?” Twilight tilted her head and raised an eyebrow at Rainbow.

“I, uh, you see, I, um, kind of... oh Celestia, how do I explain this?” She looked to the ceiling, as if it would hold the answers she needed.

“Rainbow, you know you can tell me anything. We're friends, right? Friends can trust each other, right?” Twilight reached out and gave Rainbow a comforting pat on the shoulder.

“Friends, right. That's... that's the thing, Twi. I, I like you.” Dash was straight-faced, but her eyes told another story.

Twilight giggled at the statement. “Well, of course. Could you be friends with somepony you didn't like?”

Rainbow sighed. “No, Twilight. I like you like you.” Her eyes pleaded for acceptance.

“Oh.” Twilight started blushing, almost rivaling Rainbow Dash's.

“You, you don't think of me like that, do you?” Tears began welling in her rose eyes. She turned away, ashamed.

“Rainbow, I... uh...” Twilight held out her foreleg, but withdrew it nervously.

“Of course not. Who would like brash, dangerous, loud-mouth Rainbow Dash? Nopony, that's who.”

“Rainbow...”

“It's OK, Twilight. I'm used to it. It's hard enough, being like me.”

“Rainbow...”

“No, I get it, 'yer barn door jest don't swing that way'.”

“Rainbow!”

“What?!” she shouted. Her anger dropped when she saw Twilight's gentle smile.

“I've never thought of anypony like that. I didn't think anypony would like me, so I didn't bother. You're a great friend, and a wonderful and talented flier, and you're confident, and really pretty...”

“Hold up, what?”

“I think you're really pretty.”

“You think I'm pretty? Like Rarity-girly-pretty?” asked Rainbow, confused and incredulous.

“No, like a carefree pretty. Like, you just are pretty.”

Rainbow continued blushing, but she finally sported a smile. A small, shy smile, but it was there.

“I think you're pretty too.”

“Sorry, I didn't catch that,” said Twilight, with a sly grin.

Rainbow leaned closer and said, “I think you're pretty, too.”

“Sorry, still didn't get that.”

Rainbow, giving up, just put a hoof behind Twilight's head and pulled her in for a kiss. Twilight's eyes shot open in surprise, but fluttered shut as Rainbow continued the kiss.

“Did you get that?” asked Rainbow, now grinning from ear to ear.

“Mmhmm.” Twilight's eyes were still closed, a blissful smile plastered on her face.

Rainbow let out a breath. “Thank Celestia. Last time, she ran off.”

“Wait, what happened last time?”

“My first kiss. At summer flight camp, when Fluttershy finally managed to get back to Cloudsdale, she came to thank me. We spent the rest of the day together, just hangin' out, you know? When the sun was going down, Fluttershy leaned against me. I thought it was really cute, so I leaned down to kiss her. She squeaked and flew off.”

Rainbow let out a heavy sigh before she continued.

“When I finally caught up to her the next day, she said she didn't think of me like that, but that we could still be friends, 'if that's what I want, if it's OK with me.' It's hard, being a filly-fooler. You never know who else is like you.”

“Oh, Rainbow, I'm so sorry.” Twilight wrapped her forelegs around her friend, bringing her in to a tight hug. “I never really gave it much thought. My parents never talked about me liking mares or stallions when I was growing up, and I always had my books. I guess… I guess I don't really know.”

“Do you want my help with that research, too?”

Twilight chuckled and released Rainbow. “Maybe...”

Rainbow's grin turned mischievous and she pounced on Twilight, pinning her to the ground. This time, Rainbow poured all of her passion in to the kiss. Her tongue slid out of her mouth and licked Twilight's lips, which parted and allowed Rainbow entry. Her tongue probed and licked and wrestled with Twilight's. Both mares' breathing became heavy, soft moans punctuated by deep breaths. Twilight broke the kiss, catching her breath and smiling at Rainbow.

“I... uh, wow. Really, just, wow,” she said between breaths.

“Betcha your books can't do that,” said Rainbow cheekily.

“No, no they can't.” Twilight reached up a hoof and began stroking Rainbow's mane.

“Where is Spike, anyway? I'd hate for him to just walk in on us.”

“Rainbow, we're surrounded by books stacked as tall as we are. I think we'd notice if he came in, and he wouldn't be able to see us. But he's out gem-hunting with Rarity. He shouldn't be back until dinner time.”

“Still. I don't like an audience. Not for this, anyway.”

“I understand. But would you mind letting me up?”

“Hmm? Oh, sorry.” Rainbow moved her forelegs from the side of Twilight's neck and allowed her to get up.

“While that was fun, the hardwood floor isn't all that comfortable. Do you think that we could maybe, uh, take this upstairs?”

Rainbow smirked. “That's a little fast, don't you think? Not that I'm complaining...”

“Rainbow!” Twilight playfully batted Rainbow's shoulder. “Not like that. I just... wouldn't mind someplace more comfortable.”

“Fine.” Rainbow allowed another mischievous grin to grace her face. “Only for you, Twi.”

Twilight smiled back and led Rainbow up to her room. Both hopped onto Twilight's bed. Twilight turned to Rainbow Dash and tucked her hooves underneath herself. Rainbow did the same, still grinning. Her tail swished behind her for a few moments, before Twilight reached out her forelegs and wrapped them around Dash's neck.

“How long?” Twilight asked. A shy smile played across her face.

“How long what?”

“How long have you... had feelings for me?”

“I dunno. A while, I suppose. Probably since last fall, when you beat me and AJ in the Running of the Leaves. You outsmarted me and beat me at my own game. Normally, I'd be furious, but you really showed me that some ponies are full of surprises and that I should respect everypony's abilities. So I respected you.... And I learned to respect myself. Which led to me accepting who I am and who I want to be with.” Rainbow leaned forward and kissed Twilight on her muzzle. “And then you showed me something really special. You gave me that Daring-Do series, and opened up a whole new world for me. And maybe I can do the same for you...”

“Aw, Dash, that's sweet.” Twilight smiled, her eyes half-lidded.

“And here I thought I was no good at the mushy stuff,” Dash joked.

“You sell yourself short.” Twilight wrapped her hooves tighter around Rainbow and kissed her neck. She continued, whispering in Dash's ear, “You can do anything. You did a Sonic Rainboom twice. You've saved so many pony's lives and brightened so many others. You've always been a fantastic, loyal friend. And I hope that's not all.”

“Oh? What are you getting at, Twi?”

“Well,” Twilight began, grinning, “I've learned a lot about the magic of friendship. But I know nothing of the magic of romance. You've been... very helpful today. So, I was wondering if you'd be my―”

“Marefriend?” Rainbow asked, brightening at the question.

“Research assistant.”

“Let's go with marefriend, Twi.”

“Marefriends it is, then.” Twilight shut her eyes, and leaned in for another kiss. Rainbow grasped Twilight's face with both hooves and pulled her in to another deep kiss.

When Rainbow finally broke the kiss, she snuggled up to Twilight and draped a wing over her. Twilight giggled and shivered at the soft feathers tickling her back and pressed into Dash. Both gazed out the window, falling asleep next to their special someone.