Several very expensive and entirely magic-free instruments beeped in a slow, steady rhythm. Getting the operating theatre prepared had been a not insignificant part of the budget, but one that couldn't be avoided. It was a cleanroom, cut off from outside leylines and background magic, with specially-made scalpels ground from scraps of cold iron.

"Insert the Heart opposite her actual heart," Doctor Sparkle instructed, not that she needed to. They'd gone over the operation in detail, her obsessive attention to detail demanding that they use a cadaver for the dry run, which hadn’t prepared Sunburst for just how much throbbed and moved inside a living subject.

“You realize none of us have medical degrees?” Sunburst asked, for the third time.

“It’s just... wet engineering,” Sparkle assured him. “No different from changing the focusing disc on an interocitor.”

Sunburst worked with her to lower it gently into place, the lump of metal and gems looking out of place against the pulsing red and pink around it.

"Her vitals are starting to fluctuate," Moondancer reported. "I'm going to give her another unit of plasma to try and bring her blood pressure up."

Doctor Sparkle nodded, trusting Moondancer to do her job.

"Once the Heart is anchored, start it up at low power," Doctor Sparkle added. "The effects should help stabilize her."

"Ready," Sunburst said, stepping away from the patient. "Bringing the power up to ten percent." He attached a slim glass probe into the Heart, the other end leading to a squat, bulky machine. Sunburst turned the dial, and the room filled with a hum more felt than heard, making the unicorns' horns ache with resonance before it faded.

"Make it fifteen," Sparkle said, glancing at one of the displays. The lines rose and stabilized, and red slowly turned to yellow and then green. "Excellent. Let's get her closed up."

Lightning Dust woke slowly, her chest feeling tight and broken, like she'd gotten on the bad side of an earth pony who really knew how to throw her weight around. Something was beeping, the sound annoying enough to make her crack her eyes open in search of the source.

"...This isn't a hospital room," she said, weakly. Everything felt heavy. She knew the feeling - she'd been drugged, unconscious for a while. And looking at the ceiling, and the recently-patched hole in the wall next to the door, she had a pretty good idea of where she was.

"I'd prefer if you didn't break out of the room this time," Doctor Sparkle said, as the door slid open. She limped on bandaged hooves, sitting down next to the bed to get weight off of her front legs.

"So Doc, am I gonna live?" Lightning Dust asked, smirking.

"It seems so," Doctor Sparkle said. "It would actually be quite difficult to kill you, now."

"How do you figure that?" Lightning Dust asked.

"That depends on how much you know about metaphysical biology." Doctor Sparkle took a sheaf of papers out of her labcoat and flipped through them.

"Let's pretend I didn't go to college--"

"We don't have to pretend on that count," Doctor Sparkle mumbled.

"Owch. You know, I was planning on getting a degree. I had all kinds of scholarships lined up and I was totally gonna get in but, well, you know. The war."

"Mm. The war, indeed." Sparkle turned the papers around so Lightning Dust could see what she was looking at. It was a diagram, an ancient one, showing a pony with a horn and wings with eight legs in different positions within a circle and a square.

"I've seen that one. The Vitruvian Alicorn, right?" Lightning Dust shrugged. "It was in Lionheart d'Veneigh's sketchbooks. I saw them at the Canterlot Art Museum once."

Doctor Sparkle blinked once, slowly. "I wasn't aware you had an interest in art."

"I don't, but I was dating this really hot mare at the time. A little older than me, that kind of mature type you know? You kind of pick things up. Like there was this one artist, Cutie Reinko. Did the most amazing things with color. There'd just be a couple of rough squares of color on a canvas and it'd have this weird beauty behind it." She laughed. "Man, these drugs are making me talk way too much."

"A near-death experience does that to some ponies. You're right, though. It's the Vitruvian Alicorn. A print of it, anyway. For a long time, it was debated if it represented an overlapping view of all three tribes or a single alicorn."

"I think they eventually decided it was the same thing either way, right?" Lightning Dust tried to shrug, and immediately regretted it.

"It's neither of those." Sparkle tapped her hoof against the background. "A square and a circle. Drawn so accurately that they have almost precisely the same area, to a degree that would require machine-like precision."

"d'Veneigh was talented," Dust shrugged.

"A genius, if we're being pedantic," Doctor Sparkle smiled a little. "There's been a lot of study on this diagram, but I suspect very few have seen the second version."

"Second version?" Lightning Dust sat up, ignoring the pain in her chest and back.

"I was given a few of Lionheart's journals by..." She scrunched up her nose, trying to decide on the right term to use. "I hesitate to say patron, but an interested party. She'd been holding onto it for some time because of the information inside it."

"He's been dead for centuries," Lightning Dust said. "I don't think he had anything really earth-shattering to say."

"You'd be surprised," Sparkle said. She flipped to the next page. It was a diagram similar to the Vitruvian Alicorn, but with more to it, like he had tried to capture something on the page that couldn't even be constrained to three dimensions, much less two. A grid of something like constellations, notated in a language Lightning Dust couldn't read, was captured inside the pony.

"What's that supposed to be?" She asked.

"The leylines inside a pony. He tried to convey where they merged, where they terminated, where they'd grow and change. These points--" she tapped one of the star-like shapes. "Are the chakras. The larger circle in the center is a wellspring."

"Which is where magic comes from," Lightning Dust said, sure of herself.

"Correct. It's where the astral body and the physical body intersect, but your description is more or less accurate for a laypony."

"There's something strange in the corner." Lightning Dust narrowed her eyes, leaning in. There was a figure there, twisted and black, just a sketch, a suggestion of plates of hardened armor.

"It's nothing. Lionheart drew a lot of odd things," Sparkle said, dismissively.

"So what's all this about? I can't read any of it."

"He wrote in backwards Horse Latin to keep his thoughts a secret," Doctor Sparkle said. "But in general, he found that the greater a pony's magical strength, the more they diverged from what we might call normal biology."

"What's that mean?"

"Beyond a certain magical strength, your body changes. Look at dragons - no natural creature can breathe fire, and nothing that large should be able to fly. Even a pegasus shouldn't get off the ground with how tiny your wingspans are."

"Hey, I can fly like crazy!" Lightning Dust huffed, annoyed.

Doctor Sparkle nodded. "Indeed. Because you use magic for it. And your high base magical talent means your biology has adjusted for it. Without getting into detail you couldn't appreciate while you're on opiates, partly sedated, and entirely uneducated, think of it like... physics and biology is a rulebook, and the stronger your magic, the fewer of those rules apply to you. Beyond a certain point, you become totally dependent on magic to survive. Dragons, for example, cannot enter dead magic zones or else they tend to, ah, fail explosively. It's like deep sea fish being brought up to the surface."

"Is that why the Princess is immortal?" Lightning Dust asked.

"Princesses," Doctor Sparkle corrected. "There are more than one. But yes. Alicorns are immortal because their personal magic is so strong that they no longer have cellular processes as we would normally understand them."

"I think I'm in a little over my head."

"Mm." Doctor Sparkle shrugged. "I doubt you'd appreciate the irony of Lionheart d'Veneighs trying to describe alicorn anatomy in light of their separation from baseline reality, then."

Lightning Dust shook her head, shrugging.

"To the point, then. You're somewhere between the average pony and an alicorn. Not quite immortal but... harder to kill. You could say that your will keeps you in the world longer than a mere body would allow it."

Doctor Sparkle paused, trying to think of a better explanation. As she was working through dumbing down an explanation of Magical Territory fields to use words with few enough syllables that even Lightning Dust could explain them, she heard a distinctive buzzing sound.

She looked up and saw Lightning Dust sitting on the bed, eyes closed, drooling and asleep. Doctor Sparkle rolled her eyes and pushed the pegasus gently, letting her fall back onto the pillows.

"Sleep while you can. There might be a lot of long nights ahead for all of us."

Lightning Dust saw the wall coming, not that she could have missed it in any sense of the word 'missed'. She tried to stop herself, but instead she found herself hitting plaster, then wood, then out into a hallway before coming to a stop. Stitches tore on her chest and back, blood dripping from her coat.

"Okay, that one was my fault," she admitted.

"Don't move!" Sunburst yelled, alarmed. He rushed over with a first aid kit and examined the surgical wounds. "You shouldn't even be out of bed. The average recovery time for open-heart surgery is--"

"Irrelevant," Doctor Sparkle said, cutting him off. "Glue her shut. I don't want her bleeding everywhere. I doubt the Young Mares Celestian Association are going to be happy about cleaning this up."

"Such amazing bedside manner," Lightning Dust snorted. "Do all your patients get this special treatment?"

"We're not at a bedside, and I'd have to go to medical school to learn it," Doctor Sparkle said.

"Wait, you operated on me without a medical license?" Lightning Dust's wings flared up, knocking Sunburst over while he tried to get her back wound closed. “I thought you were a doctor!”

"A doctor of thaumatic engineering. But don’t worry yourself - I made sure to read several medical texts while getting ready for your surgery. You're alive, so you don't have anything to complain about."

"She's joking," Sunburst said. "Sort of."

"You're healing at an astonishing rate," Doctor Sparkle said, smiling slightly. "Not fast enough that you can smash through walls without hurting yourself, though."

"Well I didn't know trying to take off was going to do that!" Lightning Dust pointed back through the hole to the track beyond it. Curious ponies were already looking, heads peering around the edges of the broken wall. "We should have done this outside!"

"It's too dangerous," Doctor Sparkle said. "Indoors we can keep you contained." She paused and reexamined the debris. "Mostly contained."

"The wall did eventually stop her," Sunburst said with a shrug.

"Make a note to add a track and physical fitness area to the lab," Doctor Sparkle said. "We could armor and pad the walls to make them safer to crash into at higher velocity--"

"Hey!" A mule pushing a cart yelled, waving a broom. "What are you kids doing?!"

"It's time for us to leave," Sparkle said, backing away.

"Cheese it!" Lightning Dust yelled, flapping her wings and immediately going out of control, smashing through a water fountain, broken pipes spraying into the air. "My bad!"

"This is so stupid! I can't even get off the ground!" Lightning Dust muttered. "I could fly better than this when I was a foal!" She winced as Sunburst re-stitched the wound in her back. She wasn't complaining about it - he wasn't doing a bad job and it needed to get done, but it was just yet another thing adding to her frustration with the world in general.

Doctor Sparkle snorted. "That's the complete opposite of the truth." She watched Sunburst's work intently. "When you were a foal you had to build up strength to match your instincts. Now you have to build your instincts to match your strength."

"Huh?" Lightning Dust frowned. "What's that supposed to mean?"

"A normal pony trying to get better at flying trains both mentally and physically, yes?" Doctor Sparkle asked.

"Of course." Lightning Dust shrugged. "Some ponies go in for the whole waterfalls and meditation thing. I know this one mare I went to school with tried it with a rainbow waterfall and went blind for a week."

"Before, you were able to adjust to those changes faster than they accumulated. With the Heart inside you, your wingpower is vastly increased." Sparkle paused. "No, more than that. Just look at your wings." She stepped closer to lift one up. "They're already growing proportionally larger and stronger. When you flap your wings, not only is there more magic behind them, but your balance is off - the larger surface and greater strength gives them much more lift than you're used to getting."

“So what, I have to grow into them?”

“If you like. Consider it physical therapy after your life-threatening injury. Take it slow and you’ll be in the air in no time.”

“I’m not big into taking things slow.”

“Mm. I do have one idea, then, if you’d rather push things to the limit. How would you feel about a little friendly competition?”

“Welcome to the 1006 Summer Cloudsdale Games! I’m your host, Funky Flashmare, and with me today is Fire Streak, a senior member of the storied Wonderbolts! Let’s all give him a round of applause!”

“Thanks, Funky. I’m just glad I was invited to be here today. It’s been a long time since I competed in the games myself but they’re some of my happiest memories, even if I didn’t get quite as many gold medals as I’d like.”

“Five isn’t enough?”

“As any of the ponies out there can tell you, when you’re a Wonderbolt, you’re always looking to the next goal.”

“Well said, Fire Streak. And as I understand it, you trained quite a few of the ponies who are going to be showing us their best today?”

“That’s right, Funky. I’ve been focusing more on instructing the next generation of heroes and athletes, and I can tell you we have a good number of amazing competitors out there today. I’m looking forward to seeing how they do under pressure - having the crowd watching you can be an amazing motivator to bring out the best of the best.”

“I couldn’t agree more, Fire Streak. And with that, let’s all stand for the Cloudsdale Anthem.”

Hark! When the rain is falling!
Hark! Hear the thunder calling!
Stormclouds roll from our outpouring;
We pegasus few and proud;
Now our mighty wings are soaring;
And we feel our hearts are roaring;
Our spirits high as our home in the sky!

“And here comes the Parade of Communities. It seems like we’ve got representatives from almost every town and city in Equestria, Fire Streak.”

“Even with the war on, you can’t stop the spirit of competition. I’d like to take a moment to thank the members of the EUP who are still on deployment and unable to attend today - your sacrifice is keeping us all safe. Until you can come home safely, we’ll be carrying the torch and hopefully setting some new records!”

“Very large contingent from Cloudsdale, and Las Pegasus isn’t far behind. Hopefully all those sequins aren’t going to hurt the aerodynamics.”

“Knowing that team, they’ve probably got something skintight on under those jackets. In the 984 games the judges made them change uniforms before an event because they were distracting the other competitors.”

“Too many sequins and beads?”

“Too much and too little at the same time. There were foals in the audience, after all.”

“Well what happens in Las Pegasus stays there, right?”

“We can only hope.”

“Unless I’m mistaken, that’s Thunderlane leading the Ponyville team. Isn’t he one of your personal students?”

“Indeed he is. He’s a favorite to win this year in most of the events - he’d be a member of the Wonderbolts right now if we were accepting applications. To anypony in the audience, I’d recommend trying to get an autograph. They’re going to be worth a lot in a few years when he’s got some gold under his belt.”

“Any tips on his strongest events?”

“He’s an endurance flyer, Funky. He’s set an unofficial record for the marathon that I expect him to beat today, and I’d be shocked if he doesn’t win the wrestling competition. No offense to the other brave ponies competing, but that stallion is as strong as an earth pony!”

“It looks like we have one last group entering the stadium. And they’re from… Canterlot? I wasn’t aware we had a team from there this year.”

“Well traditionally they send a few guards purely for exhibition rounds, but they’re all understandably busy. I was down with the judges when this team came in, though I’m not sure if it’s really a team. They only sent one pony, a rather infamous one, I’m afraid.”

“Do my eyes deceive me or is that…?”

“Lightning Dust. Didn’t think she’d have the gumption to show up after some of the things she’s accused of. I expect the judges will be watching her very carefully.”

“From the booing I think the fans in the stadium tonight recognize her.”

“She has a bad reputation after, well, this is a happy event, folks. Let’s try to focus on the competition and the sport instead of past accusations. In ancient Pegasopilan tradition, we’ll let the games decide if she’s worthy of them or not.”

“This is the dumbest thing I’ve ever done,” Lightning Dust grumbled, as she walked back to the small locker room they’d been assigned. “All those ponies hate me!”

“I can assure you it isn’t the dumbest thing you’ve ever done,” Sparkle corrected. “It's not even the dumbest thing you've done since I've met you. This is one of my ideas, so it’s automatically a good one.”

“Explain to me again how competing in the Cloudsdale Games right after I was dead on the slab is a great idea. I'm half stitches and glue!”

Doctor Sparkle adjusted her glasses. “You were barely dead for ten minutes before we got your heart working again, stop complaining. The timing could be slightly better, but the Games give us a few unique opportunities that won’t come around again for two years.”

“And those opportunities are…?”

“I think we can both agree that we needed a larger arena to test your new limits?” Sparkle asked. Dust nodded in agreement. “This is one of the largest in the world. More importantly, it was cheap to enter. The entry fees for Canterlot were already paid, and I just had to have my agents grease a few hooves to get you on the list.”

“I’m still not sure about that part. Couldn’t we use an alias?”

“Don’t be silly. I know you want to set records in your own name. And since we’ll have some of the most sensitive equipment and skilled judges in the world measuring your achievements, we’ll be able to get a real sense of what you can do. It’s win-win.”

“Okay, look, what I’m worried about is a mob of angry ponies trying to drag me out of here. After the thing with the Wonderbolts and Spitfire, I have a lot of ponies angry with me.”

“Irrelevant. There’s security in place if they try anything, as if you’d need it to fight off a crowd of civilians.” She fixed Lightning Dust with a look. “And the crowd loves a winner. Don’t forget that. Show them you can defeat any normal pony. Crush the records. Show them the results of my genius.”

“You mean my skills.”

“If it makes you feel better to call it that. Don’t hold back.”

Dust swallowed. Her chest felt tight, partly because she had a big lump of metal in there and partly because of the stitches and also partly because she was standing in front of a crowd of ponies that really didn’t like her very much.

“You have a lot of gall showing up now,” growled the pegasus in the lane next to her. “I’ve been training for years for this, and somepony like you is just dishonoring the Games.”

Dust glared at her.

“We all heard about how you signed up at the last minute. What, you think you can just waltz in and win because you were a Wonderbolt? The Wonderbolt that got the rest of them killed?” She spat. “That attitude is why you’ll lose.”

The starting buzzer sounded while Dust was trying to come up with a response.

The other ponies took off, ready for it.

“Get moving, you idiot!” Sparkle yelled, from the sidelines.

Lightning Dust kicked off the line, already ten meters behind the others thanks to her hesitation. It was a bone-headed move, the kind of thing that would, for most ponies, ensure they lost the race. At this level the finishing times for the racers were usually tightly grouped, often requiring a photo finish.

Dust reached for the power inside her, the reserve every athlete has, pulling at her magic. Instead of the well of strength she’d always had inside, she found a wild, roaring storm.

Acid-green lightning filled her contrail, and she jetted ahead of the others, her wake throwing the nearest ponies out of their lanes as she careened ahead, crossing the finish line before she was ready for it and skidding to a stop, kicking up wide troughs in the clouds as she steadied herself, trying to fight down that surge of power that was burning inside her.

“What in Tartarus was that?” One of the judges yelled.

“I’m in trouble, aren’t I?” Dust groaned.

“You set a new record, even with that awful start,” Doctor Sparkle said, as Dust sipped on a bottle of Hydrade (the official sports drink of the Las Pegasus Hydras). “Two of the three judges watching the event were in position to see that you weren’t intentionally attacking the ponies next to you. They got themselves knocked out of the race by the turbulence you caused, which isn’t against the rules.”

“That wasn’t quite what I was expecting,” Dust admitted.

“We’re here so you can get used to that power somewhere safe,” Doctor Sparkle assured her. “You’ll figure it out.”

“It isn’t like my own magic,” Dust said. “I thought it would just be me, but more of it, you know? Instead, it was…”

“I tried to explain this to you while you were in recovery.”

“I’m still in recovery. I just had open-heart surgery. I should get a medal just for being here!”

“You’re already getting a gold medal, don’t get greedy and demand a damn participation trophy too.” Sparkle smirked. “Just remember, that magic inside you, half of it is yours and the other half you need to make yours. Don’t fight it, use it. Use every bit of it. The more you embrace it, the easier it will get.”

“What about the armor?”

“Unfortunately we couldn’t use it,” Sparkle’s smirk faded. “I checked and the uniform regulations are surprisingly strict, especially as regards enchanted or thaumotechnical items. Apparently, there was a scandal with Stalliongrad… anyway, the armor isn’t important for now. It will help focus your magic, but the most important component is inside you already.”

“My bravery and belief in myself?”

“Don’t be stupid. I mean the Engine Heart and you know it.” Sparkle patted her on the back. “Now go out there and push yourself to the limit or else I’ll find a pegasus who can.”

“Well, Fire Streak, I have to admit that this isn’t exactly what I was expecting from the track and cloudfield events.”

“No, Funky, I don’t think anypony was expecting it. But I’m not as surprised as you might think.”

“You knew Lightning Dust personally, didn’t you?”

“That’s correct, Funky. I helped train her. She set quite a few academy records that still stand to this day. While we might all have some opinions on her personal conduct, I can’t say she’s a pony who slacks off. She was always willing to push herself to the edge.”

“Some of these records she’s setting today are beyond belief, though, Fire Streak. She’s set the world record in every single sprint event!”

“Aside from the 75 meter.”

“That’s only because the judges had her drug tested while that event was going on and she didn’t have a chance to compete. For the record, folks, everything came back clean, and despite her unicorn coach, there’s no spellcasting involved. As far as we can tell, she’s doing all of this legitimately.”

“We’ve got the 50 meter event, the last of the sprint events for today, coming up in a few moments. I’ve also got word here from the medical teams that apparently, Lightning Dust is still in recovery from surgery. They’re not even sure she should be competing at all with her injuries, but since she’s signed a waiver there isn’t anything barring her.”

“Surgery? Well, even I, Funky Flashmare, have to give her some credit for deciding to compete despite that handicap.”

“Not much of one, apparently, since she keeps winning. And there she is on the starting line. They’ve put her on an outside lane this time to try and minimize the wake effects she keeps generating. Apparently, it’s unavoidable with the amount of wingpower she’s generating.”

“Do we have a number on that, Fire Streak?”

“Well, as you know, my own wingpower was measured at almost twenty when I was at my best, and Spitfire managed almost twenty-five. Ten or so is about average for a pegasus.”

“I went to Flight School too, Fire Streak.”

“I’m just walking the audience through things, Funky. We’re getting readings in three digits for Lightning Dust, which means either she’s found an amazing new workout routine, or we need to calibrate things.”

“Want to place a bet on which?”

“Not on your life.”

“Here comes the starting bell and- stars and garters, what was that?!”

“You broke the sound barrier from a standing start,” Doctor Sparkle said. “Not bad at all.”

“Not just the sound barrier. I broke some of the stadium.”

“They’ll fix it,” Sparkle said, dismissively. “If they weren’t ready for supersonic ponies they’re the ones at fault. The important thing is you definitely set the record there, and I think you’re finally starting to draw out the Heart’s full power.”

“I gotta admit it felt good,” Dust said. “Everypony else might as well be standing still.”

“When ponies talk about you from now on, they’re going to remember the pony that won all those gold medals.”

“So are we done?”

“Don’t be silly. You’re up in the javelin throw next.”

“I’ve never thrown a javelin,” Dust hissed, as she watched the ponies ahead of her.

“So?” Sparkle shrugged. “You get three tries. You’ll figure it out. How hard can it be to throw a stick?”

“Ponies literally train for years!”

“Mm. Learn quickly, then.”

Dust glared at Sparkle as the judges escorted her into the field.

“Stupid doctor thinks she knows what it takes,” Dust grumbled, taking a javelin from a judge and hefting it, trying to match the form the others had used. “I don’t even know what I’m doing!”

She ran forward and threw it as hard as she could.

There was a crack as the spear left her hoof. The clouds overhead vanished in its hypersonic wake.

“...” Dust bit her lip. “Huh.”

Every pony tribe has its own magic. Let us call each of these types of magic a string on some great cosmic instrument. Every earth pony is on one string. Every pegasus pony is on a second string. Every unicorn pony on a third.

Each of those ponies plays their one string differently. Perhaps they tune it a little higher or lower, or they pluck it particularly hard, or play so softly it can barely be heard, but they can never play a different string.

In this tortured metaphor, which is distressingly inaccurate but easy to grasp, imagine a pony that can play all three strings. Not only is their range of notes far wider than any single tribe could manage on their own, but they can do something no tribe can.

An alicorn plays three notes all at once, and in doing so, creates a chord. A unique signature. Something greater than the sum of its parts.