In a perfect world, that would have been that. Both would have agreed with Twilight, and together they would have resolved everything to the satisfaction of every pony, changeling, and human involved in a way that fit neatly on a one-page checklist.

Twilight was painfully aware that this was not a perfect world. Luna wasn't budging. Literally not budging from her position atop Photuris with her horn at the queen's throat. She didn't even take her eyes off of Photuris as she said, "Thy merciful heart does thee credit, Twilight, but forget not that this fiend would swallow it whole."

Twilgiht tried her best to keep her frustration out of her voice. "That's the thing. She's trying not to be fiendish."

"She is a changeling, Twilight. Deception is their blood and falsehood their every breath. She would claim to be thy own mother if it stayed thy hoof."

Photuris gave an uneasy smile. "I'm willing to admit that Hurricane was overreaching."

Luna pressed the tip of her horn against the queen's chitin. The drones surrounding them tensed and crouched. "Silence, insect. Thy betters are speaking."

"Okay, Luna?" Twilight took a few slow steps towards her. "First of all, I need you to calm down enough to use modern pronouns. Can you do that for me?"

"Treating me like a foal having a tantrum makes that no easier, but for th—" Luna gritted her teeth. "For you, Twilight, I can make the effort."

"Okay. Good. I don't suppose I can convince you to stop trying to stab Photuris in the—"

Luna's gaze pinned Twilight, making her uncomfortably aware of how the dark red lighting made Luna's coat look Nightmarishly black. "Neigh, you cannot."

"Well, foal steps." Twilight carefully disregarded the incredulous looks that got from every changeling in the room, Photuris included. "Secondly, Thorax."

"Thorax is an aberration among aberrations. A welcome one, but an anomaly all the same. This one is—"

Twilight took the opening the moment she saw it. "She's someone you can understand better than you think."

For a moment, Luna just stared at Twilight, her "what modern nonsense be this" face on full display, halfway between confusion and scorn. "In what way?"

"She's trying to be Celestia."

"She's what?"

"I'm what?"

Twilight turned to Photuris. "Even putting aside the big white alicorn disguise and the imitated mannerisms, you're trying to protect your people as you establish your rule in a politically hostile land. You plan on relaxing that protection and letting them flourish more on their own once the situation stabilizes. That's the first hundred or so years of Celestia's rule in a nutshell. And let's not forget your personal students."

Luna arched an eyebrow, horn still at Photuris's throat. "Personal students?"

"A pair of foals who utterly adore her, and to whom she's teaching truly valuable lessons. But she's also making the same mistakes as Celestia."

"Being so sure of herself and her beloved stratagems that she cannot change direction even as she charges towards disaster?" Luna scoffed.

Twilight cleared her throat. "Not how I would put it, but... yes. I should know, I have similar moments myself. It's what happens when we both try to model our rule on the same pony. Photuris, I do believe that you want what's best for Equestria, but your methods aren't needed anymore. You said it yourself, change is hard." Twilight offered the queen a smile. "Do you think you can change your mind?"

Photuris looked back and forth between the alicorns. "Even if I say yes, I'm not sure if Luna will believe me."

"I will not." Luna gave Twilight an only slightly less scathing look than the one she was using on the changelings. "And why do you say I could understand a creature striving to be my sister?"

"Luna. Come on."

After a moment, Luna sighed, but still didn't move. "All right, yes, that was a foolish question. But she is a changeling queen all the same, Twilight, one who nearly usurped my sister's throne through guile. How can you trust such a creature?"

Twilight put a fair amount of scathe in her own expression. "I don't know. How do you think I trust a mare who tried to usher in eternal night?"

"... I find myself appreciating this side of you far less now than I did last night."

Photuris sputtered at that. That brought Luna's attention back to her. "Very well, creature—"

"Luna, she has a name."

"I am aware. Heed my words, o twisted foulness of the nether realm given grotesque flesh. By the grace of one infinitely your superior in all ways imaginable, I may spare you despite my own better judgement."

"You're doing this just to spite me, aren't you?" Twilight grumbled.

Luna's lips curved into the faintest hint of a grin. "Indeed. You are nearly as much fun to nettle as Tia." That grin vanished the moment she brought her attention back to the queen. "As for you, my mercy comes with conditions: Withdraw your foul spawn and grant us safe egress from your noisome lair."

"You heard her, everyone," Photuris said without hesitation.

Gasps rang out from the ring of changelings. One said, "But, Commander—"

"That's an order. The targets are too high-value and our position is too compromised. Even if we win the battle, we'll lose the war. Besides, their reinforcements will be arriving topside soon." Photuris looked to Twilight as she rose, Luna working the kinks out of her own neck. "And I assume you'll want to be there to tell them to stand down."

"I do," said Twilight. She put a hoof on the queen's withers. "But I want you to be able to tell them your side of the story."

Photuris shook her head. "Twilight, you just saw how Luna reacted to my very existence. What makes you think the rest of Equestria will actually listen?"

"That's your biggest problem, the problem with your entire plan. To put it bluntly—"

The cracking of Royal Canterlot Vertebrae interrupted Twilight. "The two of you may debate the merits of her mad scheme while we take our leave." Luna looked expectantly at Photuris, who nodded and led them out of the chamber. The drones buzzed away into the deeper shadows, though Twilight assumed they stayed close to their queen.

"I am really sorry about her," Twilight said to Photuris. "She still snarls at Pharynx."

"She also stands directly next to you," said Luna, who did. "Besides, I am all too familiar with the minds of those who rule from the shadows cast by brighter siblings. To suspect him is to grant him due respect."

Photuris edged more towards Twilight. "Putting aside the hornpoint diplomacy, what exactly were you trying to say?"

"It's like Luna said. You've put so much into this plan that you can't see that it's not necessary anymore. Thorax's hive—"

"Thorax's hive doesn't have access to the technology that mine does. For them, metamorphosis was the only viable way to survive after Chrysalis's foolishness. Our circumstances are entirely different. We can optimize pony-changeling relations to a point beyond anything they're capable of." Photuris shook her head, though she still kept moving, and the floor still sloped up. "I've thought about everything you might say, Twilight. This is for the best."

"I believe the modern term is 'Bingo.'"

Photuris glanced back at Luna. "Excuse me?"

"My sister and I thwarted many a foe in Equestria's infancy. Being 'for the best' was oft a popular excuse for the atrocities they performed. 'Worry not, sky sisters, the peasants will repopulate in time.' 'This is how it has always been done, holy ones, and it is for the greater good.' 'The sacrifices shall be glorified in the afterlife, kind strangers.'" Luna spat off to the side. "From what I gather, you have at least at least devised a novel evil, but its goodly guise is older than I."

Photuris turned up her nose at that. "I am working to create a society greater than anything any of the three species involved could create alone. My plan is Harmony incarnate."

"Aye? How many know they are working toward this grand goal? And how many exist merely to fill the bellies of those realizing this grand vision on their alleged behalf?"

"In time—"

"Oh, in time!" Luna all but bounced with feigned mirth. "Yea, let us look to the promised land of Tomorrow, where all feats are achieved and all plans are fulfilled, where messy reality may be forgotten and left in the dust of dismal Today."

Twilight swatted Luna with a wing before she could think too hard about the idea of smacking a diarch. "Luna, I'm trying to help Photuris."

"For reasons I cannot fathom." The two alicorns locked eyes for a short time. Twilight wasn't sure what Luna saw, but it got her to dip her head and say, "Very well, I will hold my peace. Proceed, Princess of Friendship."

"I will. Photuris, your constant focus on the same goal for so long, including how you prioritized your information network, made you miss an opportunity that opened up recently."

Photuris cocked her head to the side, eyes still forward. "Oh? What would that be?"

"Think about it. You've adapted so much human technology in ways that use your unique infrastructure." Twilight nodded to the thing in an adjacent chamber, which beat like a gigantic heart and put out enough electricity that she could feel it in her wings. "Instead of infiltrating Equestria culturally or politically, what if you approached us openly and economically?"

Photuris stumbled and looked back at her. "What?"

"What?" echoed Luna.

"I have access to another world of humans that appears to be advanced as the one you know, one with multiple geniuses who already know about both Equestria and human technology." Two, after all, still counted as multiple. "Magic is growing in that world, and it can only stay secret for so much longer. You could expand Lampyrid Solutions. Turn it into a legitimate multiversal trading company."

"That's..." Photuris shook her head. "What about love?"

"You already know the answer to that," said Twilight. "You refuse to let your hive transform because they need an incentive to work with ponies. If you openly integrate with Equestrian society, especially as a trading partner, you can offer them the same incentive that ponies and humans already have here."

"Changelings aren't exactly big on material goods," Photuris said without the absolute certainty that had stood behind her earlier statements.

"The exports to Thorax's hive say differently. Yes, you can live in a complex made of your own body fluids." Naturally, at that point the passage transitioned to packed dirt. Twilight took it in stride. "Ponies can live on the open plains and subsist on grass. But do you want to when there's a better option?"

After a few moments of silent walking, Photuris said, "There's still the issue of Equestria's defense."

"You can't put entire species in little specialized niches. That's not how we work. I know ponies who aren't happy little villagers, humans who aren't technical supergeniuses." Twilight moved to the queen's side and smiled up at her. "Your hive can have both merchants and soldiers."

They reached a door. Not some oscillating valve or dilating orifice, but a rectangle on hinges. Twilight stepped ahead of Photuris. "And you know what the thing is about spending years and years pursuing the same goal while hiding from everyone else?"

She opened the door. They walked out of a side building next to the town's cell tower, close enough to make out the chitinous texture and pulsating veins of the antenna. But that was barely noticeable compared to the skies over Galloping Grove.

Clouds of changelings darted at each other like colliding galaxies, torrents of black and pastel billowing out of each exchange. And on the edges of the conflict, pegasi in both armor and fabric flightsuits slammed down on any of Photuris's drones who lingered too far out of formation.

When the black drones tried to shift tactics and harry the harriers, the reformed changelings gathered together into a single massive wedge spearheaded by a point of forest green, charging forward in a vastly magnified version of the dive bombing from the Canterlot invasion and sending the locals scattering. At which point the pegasi started picking them off again.

On and on it went, Photuris's drones caught between hammer and anvil and never sure which was which.

"When you spend that long alone, the rest of the world working together might beat you to your goal," Twilight said as she watched. She wasn't sure how she looked at that point. She felt pride, yes, but also regret that she hadn't been able to resolve this without violence.

The pegasi and reformed changelings seemed to retreat to the ground, moving in an hourglass pattern that lured the pursuing drones together in a tight cluster just in time for a rainbow contrail to zoom down and smack them with a point-blank Rainboom.

Photuris flinched away from the brilliance. Twilight didn't even blink. "And then the world moves on and leaves you behind."

"That much I can confirm," said Luna.

"Strictly speaking, we don't need you." Twilight felt strangely detached as she said that. She's already drawn out the path of her logic. Now she was just following it to completion. "You had an amazing, daring idea. And now, so do we. We can use different materials, a different approach. But you can save us time and effort, and add so much to three different societies in the process." She held out her hoof to Photuris. "What do you say?"

The queen looked from face to hoof and back again. "You are a terrifying little pony, Twilight Sparkle."

Luna smiled and nodded. "She is at that."

"How did they train for this without my knowing? How did they know?"

"The signal to the Cutie Map included a snapshot of everything in the earring's vicinity, so they got a full picture of a lounging changeling queen. And they've been performing teamwork drills in the Badlands practically since Pharynx transformed. He insisted on giving Equestria an army he wouldn't be ashamed of working with."

Photuris closed her eyes. "I never bothered to look after Chrysalis." She lit her horn. Twilight took a step back, but then Thunderhoof's voice rang out across the city. Twilight could see one of the speakers by the cell tower, close enough to see the lips move behind the speaker grill. "Attention! This is Captain Thunderhoof. I ask that my forces stand down. There is no need for us to come to further blows. Princess Twilight Sparkle and I will meet the Equestrian representatives at Town Hall to negotiate reintegration procedures."

She opened her eyes and shook her head. "I have no idea if that worked. I have no idea if any of this is going to work."

"I think it will. Luna, we're going to need your help."

"If you will permit it," Luna said with a thin grin. "In what capacity?"

Twilight returned the expression. "The rescuers might think this is a trick and I'm just a drone imitating me, but no one will believe a changeling could imitate how you feel towards Photuris."

After a moment's thought, Luna nodded. "Indeed so." She smacked Photuris on the hindquarters with a wing.
"Come, insect! Let us away to the bargaining table."

Twilight and Photuris both watched her fly off. Once Twilight picked her jaw up off the ground, she said, "That... wasn't what I had in mind."

"I don't suppose she's seeing anypony?"

Twilight managed to keep the turmoil at that idea internal. All she said was "Do you really want to see what Celestia's like when she's being a protective older sister?"

"You're just full of excellent points, aren't you?"

"I try." Before they could delve into that topic any more deeply, Twilight spread her wings. "Come on, let's make sure Luna isn't overselling her role."

"Ah!" The human Twilight—well, normally human, currently a unicorn, and going by "Sci-Twi" because of that kind of confusion—leapt back, the probe held in her magic nearly smacking against the crystalline ceiling before she reeled it back in.

The local Twilight poked her head into the quaternary library-turned-research lab. "Is everything okay?"

"Circuitry has never squirted at me before!" Sci-Twi pointed an accusing hoof at the trail of green fluid that stretched along several inches of floor past the examination table.

"We're, uh, having some trouble with the reverse engineering," said Sunset Shimmer.

"Well, if there's anything I can do to help—"

Sci-Twi growled at the changeling phone beetle as she prodded it again. "This isn't just magical horse nonsense, this is biopunk magical horse nonsense!" She threw the probe down on the table, stomped, and turned to Twilight. "Darn it, me, I'm an engineer, not a doctor!"

Sunset snickered at that for some reason. Twilight just said, "Sorry. I'll bring in some of the biomancers from Galloping Grove to help you out."

After a deep breath, Sci-Twi nodded and picked up the probe again. "That would be tremendously helpful. Thank me."

"I'm welcome," Twilight said with a giggle.

Sunset rolled her eyes despite her grin. "You two are having way too much fun with that."

"Have you thought about the offer?" said the princess.

"'Equestrian Ambassador to the FSA' does have a nice ring to it, and being able to be honest about my origins would be nice. It's not like I was looking forward to trying to get into college with a back alley birth certificate. I'm just not sure how that world's going to take it."

Sci-Twi didn't even look up from her very scientific poking. "Sunset, even putting aside the people we've shoved through multiple portals, the secret's been out since you spent five minutes on stream apologizing to Fluttershy for calling her a 'featherbrain.'"

Twilight gasped. Sunset winced. "Look, tempers were high, mistakes were made—"

"And a thorough dissertation on tribal politics in Equestria was recorded from Spasm and posted to EweTube. Best to take advantage of this opportunity before Homeland Security decides to take the video seriously."

Sunset rolled her eyes. "Between the two of you, I can't get away with anything, can I?"

"It's for your own good," chorused the Twilights.

Twilight looked around the lake. "This is really everyone who wanted to return to their home?" Fewer than thirty orange-coated ponies, and a few in more brown or yellow hues, stood with her and Photuris.

The queen nodded, the arcing antennae on either side of her smooth, curving horn bobbing with the motion. Her carapace, red at the barrel while shading to yellow at head and hooves, made her look like a reformed changeling version of Sunset Shimmer. "I told you most of them volunteered."

"Up yours, Thunderhoof!" cried someone in the back.

She winced. "You're sure I'll ever be able to show my face in that world again?"

Twilight nodded. "I'm sure once we offer a full explanation of the opportunities for friendship at hoof and hand, they'll be very understanding."

"And the fact that they could make billions."

"As I said, opportunities for friendship."

"I'm still turning down the ambassadorship. I was already the true leader of Galloping Grove. Might as well make it official." Photuris smiled. "And it's already made for a new wave of stickers for Corn and Peg to collect. So, why the big crown thingy?"

Twilight adjusted the Element of Magic. "Credibility. We're going to need to prove that magic exists, and Elements of Harmony maintain theirs even when they travel to other universes. Ready?"

"As I'll ever be."

Photuris fired a flare from her horn. A quartet of drones touched their horns to the lake and the queen stepped through. Twilight watched the emigrants hesitate until Montague took the plunge. The others followed suit, and Twilight herself went through last.

The other side of the lake was much brighter than Twilight expected. The sun hadn't seemed to be at the right angle to cause such glare before she went through, yet now everyone was shading or just averting their eyes.

Or genuflecting before her.

At that point, Twilight realized she was hovering above the lake in a world where she shouldn't have wings. She looked down and beheld a luminous figure with a shining star on her brow, a halo of light about her face, and four wings of burning energy emerging from her back. The being was garbed in a scroll of arcane formulae strategically draped about its comely form.

Twilight gave a sigh that shook the firmament and looked up from her reflection. There was really only one thing to say. "FEAR NOT."

That actually seemed to work for most of them. Photuris, ruddy even given the limited dermal palette available, smirked up at her. "I feel like you forgot to take something into account."

"IF NOTHING ELSE, THIS DEFINITELY ESTABLISHES OUR CREDIBILITY."

Luna nodded as Twilight finished describing the finer points of her misadventures in the other human world. "I have often found that knee-buckling awe is an excellent way to get ponies to forget one's minor legal missteps."

Celestia gave her a sour look, turning back to look out over her personal balcony before Luna noticed. "I am glad to hear it went so well, Twilight. I never expected this from Thunderhoof, but you clearly handled the situation better than I did."

Twilight squirmed in her seat. "I don't know if I'd put it like that."

"I would," said Luna. "Sister clearly does. I have little doubt what Cadence would think on the matter. Even if young Flurry stood by you, that is three princesses to two. You have no choice but to feel proud, Twilight." She chuckled. "Who says democracy does not work?"

Celestia rolled her eyes, but couldn't hold back a smile. "It seems you've taught all of us a valuable lesson over these last few days."

Luna smirked at her. "Sitting back and waiting for your problems to die isn't always the best course of action?"

The faintest hint of strain marred Celestia's placid tones. "I was thinking more along the lines of 'Always be open to alternatives.'"

That got a neutral grunt. "On the subject of lessons and alternatives, are you truly sure you wish to pursue this 'School of Friendship' idea, Twilight? It seems a waste of your considerable talents."

"Well, we are getting quite a few students from Galloping Grove. They'll be there to acclimate themselves to the rest of Equestria as much as learn the curriculum." Twilight laughed. "Besides, what else would I do? Try to fill your hipposandals?"

Both sisters smiled at that, or at least drew back their lips. Celestia cleared her throat. "Heh. Yes. How ridiculous."

Author's Notes:

I figured the actual diplomatic minutiae went outside the scope of the story. The interesting part of the story, anyway.

"FSA" stands for Federated States of Amareica, because Bland Name Product isn't just for trademarks.

And this does do a nice job of explaining why so many of the students at the Friendship School seem to be around the Mane Six's age, doesn't it?

Thanks for reading. You can read a more thorough wrap-up here