"Twilight! Twilight!" a small purple drake yelled, pushing open the library door. "You're back from Canterlot"
"Spike!" Twilight called out happily, hopping down to pull her assistant into a hug. "How was staying at Rarity's?"
"Great!" Spike smiled. "She came back to the Boutique raving about how you two had won! And something about you and Rainbow Dash being married. What's that about?"
"For the last time, we're not m-" Twilight complained, cutting out when she felt Rainbow Dash put a forehoof on her shoulder. Rainbow Dash shook her head.
"Y'know Twilight." Rainbow said. "The more you deny it, the more ponies are going to keep saying it. Seeing you get that cute little huffy look on your face is absolutely hilarious."
Did I just call her cute? What?
"Fine." Twilight deadpanned. "Rainbow and I are married. We had to enter a civil union to be able to adopt Scootaloo. Who is now your... sister?" Twilight shot a confused glance at Rainbow, who just shrugged.
"Huh." Spike replied. "That's gonna be strange to get used to. I don't think I mind though."
"There's something else..." Twilight continued. "Since Rainbow and I are now legally together... we have to have the same residence. The library is a public building, so that's deemed unsuitable."
Spike cocked his head to the side. "What does that mean?"
Twilight gave herself a readying breath. "We're moving in with Rainbow Dash."
"..."
"I was thinking of the whole cloud floor problem, and I think I can make you a pendant with a crystal I can enchant with a cloud walking spell. So you can move in too!" Twilight beamed.
"In the old guest bedroom I only have one bed set up." Rainbow Dash piped up. "But I could move some junk out of that room and probably add another one. I just haven't really had any reason to clean it up 'cuz Scoots only slept in there for one night."
"There's still the problem of both Scootaloo and Spike having to have a way to access your house." Twilight reminded her. "Given that neither of them can fly."
"Yet."
"What?"
"Scootaloo can't fly yet. You're gonna help me get her to fly, right?" Rainbow Dash grinned hopefully.
"I'm gonna do my best. I can only promise that."
"Yes!" Rainbow Dash pulled Twilight into a quick hug, taking to the air with her. "Ooh, can I bring her by here after school?"
Realization of what she was doing hit Rainbow Dash quickly, and she quickly dropped Twilight. "Uhh, sorry about that."
Rolling her eyes at her excitable friend's antics, Twilight smiled. "Yes, please do. In the meantime, I'll go get some tests prepared in the basement. Wanna come help me Spike?"
"Yes ma'am" Spike saluted.
"Rainbow Dash! Rainbow Dash! You'll never guess what happened today at recess!" Scootaloo ran up to her adopted mother as she landed in front of the school, prancing in place with a giant grin on her face.
"What happened, squi-"
"Diamond Tiara apologized!" Scootaloo almost yelled.
That brat that always picked of Scootaloo for not being able to fly and not having a cutie mark? Maybe she heard about the trial.
"That's great! You want even more good news?" Rainbow Dash smiled.
Scootaloo squeed and furiously nodded her head. "There's more?"
"I got Twilight to agree to run some tests on you, seeing exactly what you need to do to get airborne."
"AHHHHH!" Scootaloo screamed in excitement, running circles around Rainbow Dash. "YES!"
Oh Celestia my heart. This filly is just too much for my heart to handle.
Buzzing her wings for extra height, Scootaloo jumped on Rainbow Dash's back with an excited giggle. Rainbow Dash took that as her cue to take off. On the way, she did some flips and rolls to elicit some more happy cheers from Scootaloo.
I wonder how she's going to take Twilight and Spike moving in. Hopefully well.
Landing and opening the door to the library, Rainbow Dash strode inside. "Twilight?" She called, not seeing her lavender friend.
"I'm in the basement! Come on down!" Called a voice from somewhere below Rainbow Dash.
Scootaloo jumped off Rainbow's back, zooming down the stairs and startling Twilight. Upon hearing the startled gasp coming from below, Rainbow Dash rolled her eyes and laughed to herself before following Scootaloo down.
Scootaloo had returned to prancing in place, watching Twilight working on unfamiliar equipment with a giddy smile on her face.
"So I did some reading on the growth and development of pegasi and their inherent magic. I've come up with a couple of tests that should help pinpoint the problem." Twilight explained. "Now I don't want you two to get your hopes up instantly. Even if we find out the exact problem today, there's no promise that it can be fixed today. Understood?"
Scootaloo looked a bit dissapointed, but at the prospect of getting closer to flying she returned to smiling.
"Originally I thought it was related to size. Scootaloo does have smaller wings than other pegasi her age. But then I remembered when we visited you at the Wonderbolts Academy, Rainbow." Twilight continued. "There we saw Bulk Biceps. As we know, his wings are also very small, but he was good enough to get into the academy. So I'm thinking size doesn't matter."
I wonder if she's ever had to tell a stallion that?
"That does narrow it down, but there's still many things it could be. First things first, I'd like to test Scootaloo's wing synchro."
Twilight leaned down, draping her wing over the filly so that the bottom of her wing just touched the tops of Scootaloo's.
"Scootaloo, would you mind flapping your wings for a while?" Twilight asked.
Scootaloo got to work buzzing her wings against Twilight's. Rainbow looked on confused. "Twilight, what exactly are you doing?"
"Well, Rainbow." Twilight explained. "There's a uncommon pegasus developmental disorder that has the wing flaps of a pegasus de-synchronize while in flight. They start out fine, but their brain messes up the signals it sends to the wings, so while one wing is up, the other is down. A pegasus can't get any air that way." Pausing for a moment, Twilight stuck her tongue out in concentration. "Okay Scootaloo, you can stop. Your wing synchro is fine."
Next Twilight instructed Scootaloo to push her wing against Twilight's hoof, going forwards and going up. Twilight mused over that for a moment.
"Well, her anterior deltoids seem far weaker than her lateral deltoids, which are actually very well developed."
Scootaloo made a confused face at that. "What do you mean?"
Rainbow thought for a moment and translated for Scootaloo. "The muscles you use for straight up flapping are strong, probably from all the scootering, but the muscles you use to get air and push air below you to get higher are weak." She turned to Twilight hopefully. "So is that the issue?"
Twilight hummed softly. "More than likely not. Even if they aren't very well developed, she still should be able to fly. I'm confident it's something else. Scootaloo, have your wings ever been damaged beyond some minor bumps?"
Twilight froze, eyes wide as she realized what she asked. "I-I mean prior to the whole... being tossed off a cloud thing." Twilight winced at her lapse of judgement.
Scootaloo sighed, the wind taken out of her sails. "No, nothing that I know of before that. Are you saying that my dad might have crippled my wings?"
Twilight didn't respond for a minute. "I'm not saying anything, dear. There's still more tests I want to run. Let's try out this magicae-o-gram. If you'd please, hop up on this table." Twilight laid her hooves on a small metal table. It looked like one you might see at a vet's office. As Scootaloo jumped on the table, Twilight wheeled over some kind of light bar looking thing, and a large swath of what appeared to be x-ray film. On top of swath of film, there was some sort of module, which was connected to a cord. The other end of the cord ran into the base of the light bar.
"This isn't going to be like the spell you did on me with Morning Skies, is it?" Scootaloo asked nervously.
"Nothing like that." Twilight soothed. She powered on the module and held the light bar up to her horn. On the film, they saw a large purple mass in the shape of a horn. "All this does is measure the magical pathways inside a pony's body. So you can see my horn is full of magical pathways, much like any unicorn."
"But Scoot isn't a unicorn." Rainbow Dash deadpanned. "She's a pegasus. Pegasi don't use magic."
"Every pony uses magic, Rainbow." Twilight lectured. "Unicorns use it for magical spells. Earth ponies use it for strength and toughness, as well as limited control over plant life, and if I'm correct... Pegasi use it for cloud walking, and I believe casting a magical spell on themselves for flight."
"So you're saying I cast a spell on myself every time I want to fly? Because I don't, Twilight. I just fly." Rainbow sighed.
Twilight rolled her eyes. "It's not a conscious thing. Here, look at this." Twilight ran the light bar across Rainbow's wing. The film showed the shape of a wing with the same purple energy apparent throughout the whole thing. "Have you ever compared pegasi to birds? The body shape of birds has a much lower body-to-wing ratio. They don't cast magic on themselves because their body shape allows them to fly without it. However, realistically without magic, not one pegasus would be able to fly because wings are naturally too small and weak to lift their whole bodies off the ground.
"If I'm right, and I will admit, this is a fair amount of postulation, I believe pegasi magic has them casting some sort of... maybe a levitation spell? A pegasus would keep all their mass, but have a reduction of weight. So if Scootaloo's magical pathways aren't intact, it's as simple as she's not casting the spell on herself, and weighs too much for her wings to really handle." Twilight turned around to face Scootaloo with an eager smile. "So, now for the moment of truth. Are you ready, Scootaloo?"
Scootaloo nodded mutely.
"Here we go..." Twilight muttered. She ran the light bar across Scootaloo's side.
Nothing appeared on the film.
"Eureka." Twilight whispered.