"I'm... sorry, what was that, Sweetie Belle?" Twilight raised her eyebrow as she lowered her book slightly, looking over the top edge at the small filly before her. The light patter of rain fell against the windows of the library, the clouds outside casting an almost ominous shadow over the library, held back only by several candles lit and placed about the room, casting a warm light on the two ponies. It provided them with a sense of solace, peace, something that was critical in teaching spellcasting.
But the question asked only moments ago took her completely by surprise.
"Well, um... how does magic work exactly, Miss Sparkle?" Belle tilted her head slightly, the expression on her face exemplifying an honest curiosity. Nothing containing a lie, not even a bat of an eyelash! The mare in the room was completely stunned, nearly dropping her book, Belle actually recoiling slightly at her teacher's surprise. She shrank slightly, curiosity quickly crumbling under a tide of embarrassment.
Twilight quickly flailed her hooves, trying to get the poor filly's attention before she started crying - something she couldn't bear to hear, let alone see! - "Oh no, Belle! I-It's alright! Just... you took me by surprise. Nopony ever explained this to you?" A shake of the head was her answer, and her jaw nearly dropped to the floor. "T-That's impossible! This is grade school stuff! C-Cheerilee never taught you?"
"We don't have any unicorn teachers at school. Just Cheerilee, who teaches us math and stuff, Hard Wall, who's our P.E. teacher, and Long Sight, who teaches us history and geography and stuff. I didn't really learn magic in school."
"That's horrible! But, I suppose that explains why you came to me. No wonder you've been having so much difficulty these past few weeks... why didn't you ask me this before?" Twilight's tone carried a hint of sympathy; she was in the same place in the past, but her parents had quickly helped her past that hurdle. Living in a city full of unicorns has its benefits, I suppose.
"B-Because I thought, well," her voice fell off as she tried to look back up at Twilight, but found herself unable to get passed the bottom edge of the couch. "I thought you'd... act just like this."
"Oh my gosh, I'm so sorry, Sweetie Belle! I didn't mean any insult, it's just, um, I-I learned all this as a filly." Twilight mentally slapped herself for saying that, "No, that's- ugh! I lived in Canterlot, and it's a city full of unicorns. I learned all this from my parents because they weren't stuck working all day, and even if I didn't have them, I had my brother and foalsitter. I can understand why you'd have trouble learning when you only had your sister."
Sweetie simply sighed, staring at the floor. "It's alright... I know I'll never know as much as you."
"What? No, Sweetie, you can definitely know as much as me. I'm being perfectly honest when all I felt was surprise, and it makes sense that you wouldn't be able to learn magic from school. So!" Twilight switched her expression from downfallen to confident, horn firing up in its usual lavender glow. Within moments, a whiteboard, several markers, and a few books assembled themselves next to her as she moved off the couch. "Ready for a lesson?"
Belle turned her eyes back up to her teacher with a grin on her face, nodding quickly. "Boy, am I! Oh, this is so cool!"
Twilight responded to the grin with her own. "Alright, Miss Belle. What do you know about a unicorn's body? Draw it up here on the board, if you please." She moved a marker over to Belle, which was eagerly snatched up in her mouth as the filly jogged to the board. With a bit of effort, Twilight found it was better to simply flip the board onto its side so the filly could draw on it. "Go ahead."
Sweetie nodded and began drawing, putting all her artistic prowess into the work. Which, judging from her... less-than-spectacular marks in art, it was understandably hard to decipher to the mare currently holding her head up. She had to tilt it under to see what it was, but no matter what angle she stared at it, it really didn't amount to much more than a couple squiggly rectangles, a wavy circle, and a small triangle sticking out of the top of the circle. "Um... ahem. Well done, Sweetie Belle, but... maybe you could prove to your teacher you know what you drew, mm? How about you point to the different spots, and tell me how they're important to a unicorn."
The filly thankfully took the wayward compliment at face value and capped the marker, putting it down on the floor. Once she'd stared at it enough that it rooted itself to the ground, she looked back at the drawing. "Well, a unicorn's most important body part is the head," She said as she put her hoof to the squiggly circle, "Since that's where all the magic is. And when we use it, it comes out of the horn, up here." She moved her hoof to the little triangle sticking out of, what Twilight could only assume, was the forehead.
"Exactly, but do you know anything else?"
"Ummm... no. Sorry," Her voice fell off again.
"It's alright, my dear scholar." Twilight smiled as she pulled Belle next to her, patting her shoulder. "Alright, how about you listen to Miss Sparkle for a while?"
"Ok!" Belle returned the smile and nodded, and the two turned back to the drawing.
"Alright. Now, you were right with the head being a unicorn's most vital asset, where all their magic, as well as smarts," Twilight tapped Belle's head as she spoke, getting a short giggle from the filly, "Are held. But, there's something you didn't know about your head, and honestly, something the rest of the country didn't know until about... three hundred years ago."
"Oh?" Belle lightly rubbed where she got poked as her brow rose up, looking up at Twilight, "Really?"
"Yep. That, my dear filly, is the presence of several organs in your head. Seven, to be exact, called the 'Magus Coti', or 'Mana Containment'. Simple, really." Twilight took a deep breath as she called up all the information she had on the subject.
Sweetie Belle braced herself as best she could.
"Three hundred twenty two years ago, a stallion by the name of Curious Riddle was researching just how magic worked in a unicorn. He was following the research done by the father of modern magic, Starswirl the Bearded, and worked with a mare named Enigma. Both were very brilliant biologists, but the mystery of magic was just beyond their field. Instead of trying to study the metaphysical nature of magic and how it affected our environment, they decided to study unicorns themselves, and how magic interacted with ponies like you and me. Through that, they studied the physiology of many unicorn subjects, and found that, despite them all having very different DNA structures, they all had one thing in common... or rather, seven things. Seven little organs around the skull in specific places, all with specially constructed veins leading up to the horn."
Twilight took a breath, not letting Belle get a word in edgewise, "These veins would be called the 'Magus Veyus', or 'Mana Vehicles', because they controlled transit to the horn. When a unicorn wanted to use magic, they would clench down on these organs and get the flow of the energy to their horn, where the raw energy would be refined and transformed by an incantation in the unicorn's mind. When the specific thoughts were processed, the neural signals would be sent to the horn and react with the raw magic, controlling its volatile nature and transforming it into useful spells. This process was called 'Magus Treves', or 'Mana Transformation', which make sense since we 'transformed' the magic using our spells. Now, the actual way magic works is, by clenching down on these organs, you get this energy to flow into your horn and get it circulating in the core, where a liquid called 'alicorn' resides. This is the catalyst needed for the nervous system to get the transformation going."
Another breath, and the mare continued, "By creating this catalytic reaction, the magic is set to explode inside your horn, but the nervous system is programmed to keep it under control by sending 'stabilizing sparks' through the 'shell', or outside, of the horn, keeping the magic contained in a kind of magnetic, compressed state. Once a unicorn has processed their spell through thought, the alicorn and energy combine into a single, airy substance that... we really haven't found a name for, but for now, and to support a theory out there that's circulating, we call it 'aura'. This 'aura' is what generates the effect of magic, from levitation to gravity reversal to transfiguration of different materials."
Belle simply stared up, completely stunned, at the mare as she carried right bloody on. "And that's not the best part! Not only does this 'mana' exist in us, but it also exists in our environment, and even in earth ponies and pegasi! It's what constitutes their magical effects as well, using hardwired 'magus cotus', or 'Mana Container', in their bodies. An earth pony's single 'magus cotus' is located in their chest, next to the heart, and a pegasus' 'magus cotus' is held between their wings at the center of the spine. It's what allows pegasi to walk on clouds, and earth ponies to inspire growth in plants! It's a truly magnificent concept, but there's even studies into Rainbow Dash and her Sonic Rainboom, and how mana may even contribute to her massive speed, AND how her body holds together!"
Finally, Twilight stopped, panting as her heart raced; obviously from excitement, rather than actual exhaustion. She worked out! Her eyes turned down to Sweetie Belle, and blinked at the filly's absolutely awestruck expression. "Is, um... s-something wrong?"
"What. Did. D-Did. Uh, bh, gk..." Sweetie's eye twitched as her brain tried to process the sheer bombshell of information that just got thrown at her. "C-Could you say that a little more simply, please? I think, um... all of that flew over my head."
"Oh, uh, sorry. I tend to get really technical. Alright, let's see... think of your 'magus coti' as, er... bodies of water, ok?"
The filly nodded, though the look of confusion was still on her face.
"And the 'magus veyes' are rivers leading from those bodies of water to your horn, which is kind of like an ocean. Ok?"
Another nod.
"Magic is like the water you see in a lake. It doesn't really go anywhere without being given a path, and a little shove. If we could press down on a lake - for instance, Lake Nimbus behind the dam -, we could get a lot more water flowing into it."
"Ok... I think I get it. So I've got seven lakes in my head, and those have rivers that lead into my horn ocean."
"Right! So, if we think of it like that, we actually get into two other terms. 'Flow control', and 'River control'."
"Flow and rivers? Wait, what? You mean magic IS water?"
"No, Sweetie Belle, but it is quite similar. Raw magic is a sort of milky substance that, despite its color and texture, flows much like water. How we know that, I'm gonna spare you the graphic details and just say, we discovered it by accident about four or five hundred years ago. Anyway. 'Flow control' is basically controlling how much magic you push out. Like so," Twilight pointed to her horn as it lit up, the dimmest of glows present. "This is me just slightly pushing down on my magus coti. And, if I... push... all the way!!"
Her horn suddenly lit up to a blinding white, filling the room with such bright, focused light, Belle could swear Celestia teleported the Sun itself into the library. It quickly went out as Twilight, nearly passed out, her eyes rolling back as she panted, struggling to hold herself up. "T-Twilight!" The filly squeaked, rushing under the mare and using her back to hold her up. "A-Are you alright!?"
"I'm... fine. F-Fine. Just... yeah..." Twilight rubbed her brow, sitting down behind Belle. "That always takes a lot out of me..."
"Was... that a light spell?" Sweetie looked up at her teacher, a scared expression crossing her face as one of exhaustion ravaged Twilight's, sweat collecting in numerous places on her face.
"The most powerful one I could make, yeah... l-light spells are just... sorry, need to get my thoughts straightened out."
Twilight took a few deep breaths every now and then, but it took her a minute to gather herself. Belle remained attentive throughout, even being kind enough to get her teacher a glass of water from the kitchen upon request, one that was hammered down like Twilight had just come back from a trip through a desert for two weeks. "Thank you, Sweetie..."
"No problem. Um... you were saying?" Sweetie sat down a good distance from her teacher, twitching every time the mare swayed too far to one side, muscles ready to react.
Twilight cleared her throat, letting out a slow exhale, "Right. What you saw a little while ago was the strongest light spell I could ever create. I did that by crushing down on my magus coti so hard, nearly my entire supply of mana was emptied... which is very dangerous, and I really shouldn't do that." She quickly shook her head, casting the dark thoughts away - she'd heard stories of unicorns who depleted their whole supplies of mana. Scary ones, but they didn't stick around long in her head -, "Anyway. A light spell is nothing more than alicorn and mana mixing together and creating an exothermic reaction, and energy being sent through the shell of the horn as a result."
"Wow... it was like staring into the sun."
"Yeah, I can create pretty bright spells. That's actually how most magic schools do their final exams for students; a student has to generate a certain strength of light spell before they can pass."
"But what if you don't have enough... 'mana', to create the spell?"
"The tests are run so physical drawbacks don't affect anything. And you can train yourself by using lots of magic. Your magus coti will actually grow to compensate for the increased mana use." Twilight smiled, proud of the result of her magic training. To have so much mana at her command, and so many spells locked away in her head, she was truly a prodigy... yet so outclassed by historical figures. She almost closed her eyes and returned to that massive vault in her head before the sight of Belle looking on at her snapped her trance in half. "Sorry."
"It's alright. That's actually really cool. But... how does this help me use magic?"
"Ahhh, my dear, that's the thing. Come over here for a moment." With a gesture of her hoof, Belle rose up and closed the gap between them, sitting back down again as Twilight's hoof set itself on top of her head. "Alright. Wanna see a cool trick?"
"Um... sure."
Belle watched Twilight move her hoof off the top of her head and move it to her forehead, pressing the tip into a spot just below the base of the horn. She made a quick jab, and Belle felt something move a short distance from the point to her horn, and her jaw dropped as her horn lit up! "W-W-W-W-W-W-W-Wh-"
Twilight giggled as the filly continued stuttering, completely stunned by what her horn just did. "Neat trick, huh?"
"I-I-I-I just used magic! I used magic!" Sweetie let out a triumphant laugh and started bouncing in place, chanting "I did it I did it I did it I did it!"
"Calm down there, missy," Belle dropped to her hooves and faced her teacher as Twilight spoke, "The trick I did there was pressing down on one of your magus coti. You see, that's one of the only things that's in common between you and me; the placement of our magus coti. There's one on each of your temples," Twilight tapped where they were, her horn lighting up slightly with each tap, "Three around your horn; two at the sides and one, just below the base - that was the one I tapped on you," Twilight carried on mapping out her magus coti with her hoof, "And two more around your head, one at the very top of your scalp, and one at the very top of your spine. All of these contribute to magic use."
"Sounds... confusing. Can we go back to the lake example, please?"
"Sure. Just think of those places as the bodies of water, and what I did was pressing down on the lake, so some of its water flowed through the river. This water ran into the ocean in my horn, mixed with the alicorn, and reacted, creating light."
"I learned that in chemistry. Neat!" Sweetie smiled, happy to be able to apply some of her knowledge to all this crazy magic stuff.
"And I'm glad you did! Know what an exothermic reaction is?"
"Exothermic is when energy is released by the reaction... and endothermic is when energy is absorbed!" Belle grinned as she got patted on the head, "Basically, exothermic releases heat and light, and endothermic absorbs energy. One makes things hot, and the other makes things cold!"
"Exactly! Wow, you're really a prodigy!"
"I try!" Belle sat back up as Twilight carried on her description.
"Anyway. 'Flow control' is basically how hard you clench down on these organs. As an example, I want you to press down on one of the organs in your head. Pick whichever one is easiest."
"Wait... but I can't even feel any of them. How am I supposed to push on something that isn't there?" Belle tilted her head in confusion, brow furrowed slightly.
"Ah, that's where you're thinking too hard. A bit like me when I started, actually," Twilight giggled at the memories of her past self trying so hard to cast magic, occasionally slipping with her muscle control and suddenly needing to go to the bathroom. The brain was a strange thing, even in Equestria's advanced age of understanding. "It's really quite simple. Move your right eyebrow up and down."
"Um, ok." Belle started raising and lowering her right eyebrow, expression changing from neutral to unsure every few seconds. "Wait... I-I think I feel something... moving?"
"That, my dear, is the magus coti held on your right temple. There's two muscles on either side of it as well, so try moving those. I found the best trick was to move my right ear and eyebrow together, just to feel it moving, then change my focus to those."
"Ergh..." Belle clenched her teeth as her right ear and eyebrow moved together. Something was definitely moving under her skin, but she couldn't quite reach with only her muscle control. Her eyes squinted hard as she tried to move it, until, finally...
A jolt ran through her head and up to her horn, but she immediately held a hoof to her head as a sudden pang of agony shot up as her horn lit with quite a bit of intensity. "OW!!!" She screamed, shaking in agony. The headache only built in intensity as her vision nearly turned red from the pain.
"Oh no!" Twilight's own horn fired up quickly, gripping Sweetie's coti and massaging it, quickly quelling the pain. Belle leaned into it like a gentle pet, letting out a happy sigh. "You pinched down really hard on it, didn't you?"
"I didn't know how hard to do it... man, that hurt!" Belle closed her eyes as she simply leaned on her teacher's magic, more being added to the aura to hold her up.
"I know. You shoved so much mana out of it, your muscles actually locked up and couldn't contract. It's a good thing you're learning from me, actually; your sister is very accurate with her magic, but you need a lot of strength to pull those tiny muscles apart."
After a few more moments of rubbing, Twilight let go and Belle came back to the world. "Thanks, that felt... really nice."
"It helped calm me down and get to sleep, actually, simply rubbing it with my magic. It's a lot better than using a hoof, since aura is much more malleable. It can re-shape itself around an object, even something as small as your 'magus coti'. Wanna continue?"
"Sure." Belle nodded, gaining a bit of a smile. All this magic business was brutal and complex, but at least she knew what constituted magic. Still, it didn't... quite answer the whole question of how magic actually worked. Her smile faded and her brow fell slightly, staring up at her teacher. "But, Twilight. Just... how does magic work?"
"Well, Sweetie Belle, that's the thing. After hundreds of years of research, and more scientists than you or I can count, we've only come to a single conclusion," Twilight showed a rather happy smile, despite the answer she was about to give. The one damning answer that she always regretted saying. But, strangely enough, when it came to magic... it just fit.
"It just does."