From its spot in the middle of Xing Xuan Wo's old laboratory, the rectangle of glass with its elaborate golden frame gave off a silvery glow that made Yue Liang's wings shiver. Shaking his head, he lit his horn, cast a heat spell, and turned back to his fellow alicorn. "A magical mirror, Bomu?"

"A portal, Yue!" Bomu Huo Hua was hopping in place, his dark purple mane bouncing along the lighter purple of his neck. "To another world! Full of ponies just like us! And I mean just like us! Their language, their culture, their magic and science, they're all remarkably similar to our own!" Bomu waved a front hoof and rolled his eyes. "Of course, they don't seem to understand how to name things properly, but, well, since they live in an alternate universe, I suppose we should allow them a few differences."

That got Yue smiling. Bomu had been trying very hard since his coronation to leave behind the academic stodginess he'd learned as Tian Shang's star pupil—

And Yue reined in that line of thinking. He had nothing but respect for his elder brother, the way Tian Shang had held Qi Ma Shu together during the thousand years of Yue's exile when he had called himself Meng Yan Yue and madness had flowed through his veins like blood. But the feelings Yue held for Bomu and his five friends—barely more than colts, any of them—who'd retrieved the talismans of the Fen Jun Heng and returned Yue to himself, well, respect wasn't nearly a strong enough word for the emotions that tightened his throat and chest when he looked at Bomu.

Shaking his head again, Yue bowed to his young friend. "I'm certain the ponies of this other world will appreciate your understanding." He straightened and gave the glowing glass another look. "Still, I'm guessing there's some reason I've heard nothing of this project till now, and a reason I'm here instead of my brother?"

Bomu went very still, and Yue's stomach clenched. "Forgive me, Bomu," he said quickly. "I didn't mean to upset you."

"No, no." Bomu's smile returned, and Yue let himself relax. "I thought I was being subtle, but I can see that's a lost cause when I'm dealing with the Prince of the Night." He drew in a breath and blew it out. "It's just, well, I've been communicating for some time with the pony whose experiments on their side connected to my experiments here, and she, you see—" Bomu gave a little snort. "There's no way to say this but to say it: she is Princess Luna, your counterpart in that universe."

"Princess?" Yue's ears folded. "I...I'm a mare in that world?"

"As is Luna's sister, Princess Celestia."

Trying to imagine Tian Shang, his larger-than-life, warrior-poet brother, as a mare jittered Yue's thoughts to a halt; he had to blink several times before he could find his voice. "Allow them a few differences, I think you said earlier?"

"Exactly." Bomu gave a chuckle. "That's why Luna and I decided to keep things low-key and quiet for the first actual physical contact between our two realms. Naturally, therefore, it was to you that I had Chang Ding send a message before I put her to bed for the evening."

Yue eyed the mirror with more interest. "The first to set hoof in an entirely different world? You tempt me, Bomu."

"No, no," Bomu said more quickly this time. "As the Prince of Friendship, I would be making the journey. Luna and I would be entrusting you with my counterpart, Twilight Sparkle. This first visit, we decided, would last but two hours so we can confirm the initial positive results of our compatibility tests, and that means that—"

"What?" Everything inside Yue began tightening again. "You would be going? But— How can you be sure it's safe? Perhaps this Luna is setting a trap for you! What do you really know about—?"

"It's all right, Yue!" Bomu sprang forward, one front hoof reaching up to touch Yue's shoulder. "In the time I've been speaking with Luna, I've come to trust her completely. After all, she's you in many ways, and there are few ponies in Qi Ma Shu that I trust more than you."

The air suddenly too warm, Yue flared his horn to turn down the heating spell. "I...I'm honored." And now that he'd had a moment to think about it, he found the idea appealing to his natural flair for diplomacy, a trait he'd developed so many centuries ago cleaning up in the wake of Tian's destructive path when they'd been building the kingdom. "A few hours entertaining an ambassador from another world is an opportunity I'd hate to miss, and I doubt it'll put me seriously behind in my work patrolling the night." He gave Bomu a smile and a nod. "Very well. I shall endeavor not to let you or this mare-me down."

"Thank you, Yue!" Purple fire surrounded Bomu's horn; turning, he shot a ball of it at the mirror's surface. It passed through, and almost immediately a dark blue ball of similar fire popped out. "That's Luna's signal!" Bomu leaped the few steps to where the mirror stood. "This will change both our worlds for the better, Yue Liang! You'll see! And thank you again!" Laughing, he pushed forward, and the mirror flowed around him like a curtain of quicksilver, drawing him in.

Frozen, Yue watched Bomu disappear, but instantly the surface began to bulge. A purple horn poked through followed by a dark purple mane with a magenta stripe—

And an alicorn stepped out.

An alicorn mare.

An alicorn mare with Bomu's wide, bright eyes, Bomu's enthusiastic scent, and Bomu's infectious grin. "Hi!" she said, her voice lovely and lively. "You must be Prince Yue Liang! I'm Twilight Sparkle, and it's such an honor to meet you!"

Yue's heart burst open like a Dragon Fruit flower, and he found himself unable to do more than stare.

---

"It's simply amazing!" Twilight Sparkle stood on her hind legs, her front hooves resting on the edge of the balcony rail, the crescent moon shining above, the night garden blooming below, her trim body stretching as she—

Yue forced his gaze away for at least the fortieth time since she had slipped from Bomu's mirror less than half an hour ago. "Thank you," he said and had to clear his throat before he could go on. "I apologize that I have nothing suitable prepared for your entertainment, Princess—I mean, Twilight, of course," he added before she could tell him again to use her given name.

She was shaking her head. "You've nothing to be sorry about. This is—" She looked over her shoulder at him, and something caught in her voice. "Absolutely beautiful," she whispered. Her eyes went even wider than usual, and she snapped back around to face the garden. "I know that Equestria has plants like these that blossom in the moonlight, and they'd be just the thing for Luna's side of the palace!"

Half of Yue wanted to read something into the way her breathing seemed to speed up, but the other half of him refused to. For all the odd circumstances surrounding the two of them standing here, this was not the dream Yue had tried so hard not to have for the past several years, the dream where Bomu Huo Hua, the pony who had saved Yue, banished his madness, and returned him to his brother and his throne, the dream where Bomu flared his horn, spread his wings, exercised the unbridled power at his command, and became a mare, a mare with laughing eyes and lips, a mare who sidled toward Yue with unmistakable intent, a mare whom Yue wrapped in his wings and held, his nose pressed close to inhale the sweet scent of her neck, of her feathers, of her—

"Your Highness?" her voice asked, and Yue startled backwards, almost tangled his hooves in the dark nebula of his tail, barely stopped himself from pitching over sideways.

She was blinking at him from the balcony rail. "Is everything all right?"

"Yes!" he more blurted than said, though he was certain the heat from his blush must be driving the stars in his mane to go super nova. "I mean—" And while he knew he was incapable of lying to Bomu or this incredible female version of him, he was careful to select a truth that was more suitable for the occasion. "I simply can't believe this is happening! Another universe? Where we all have counterparts who are mares? How is that even possible?"

Her smile, slow and spreading, lit up the darkness like clouds sliding away from the moon. "After your third or fourth alternate dimension, Your Highness, it gets a little easier." She held up a hoof. "Except you asked me to call you Yue, and I'm going to remember to do that from now on." She gave a crisp nod, took her front hooves from the balcony rail, and settled back onto one of the cushions he'd levitated out when he'd brought her here from Xing's old lab. "And I have to say that this world is a lot nicer than some I've run across."

"You've traveled to other—?" Stretching out on a cushion himself, Yue lit his horn to activate the small stove he kept here and reached into his quarters to float his teapot out. "If it wouldn't be an imposition, Twilight, might I ask that you share some tea with me and tell me of your adventures?"

There was nothing slow about her smile this time. "I'd love that!" She covered her mouth with a hoof, and the cuteness of her blush made the whispering part of Yue's mind get a little louder. "I mean, uhh, if you'll tell me some of your adventures, too. We can share tea and stories!"

At his insistence, Twilight began—most of his stories, after all, came attached to events of which he was not particularly proud...

Her stories, on the other hoof, made Yue gape in astonishment: her first told of a mirror dimension where she had become a tall, two-legged creature to match the inhabitants there, and her second of a mirror dimension where Tian Shang's counterpart, Princess Celestia, had been a villain opposed by a virtuous unicorn who, in Twilight's world, was a despotic king named Sombra.

This prompted Yue to recall the foul Queen You Yin Ying, and he started to tell Twilight about the struggle to liberate the Jing Di Guo north of Qi Ma Shu from the queen's oppressive rule—

But it turned out that she already knew the story. It further turned out that You Yin Ying must've been the counterpart of the Sombra she knew, and Yue ended up listening to Twilight tell how she and her dragon companion Spike had worked together to bring about this Sombra's final defeat. Of course, it was a story Yue already knew as well, having heard Bomu and Chang Ding's report of the same incident not so very long ago, but he listened eagerly, refilling Twilight's teacup when it came close to running dry and marveling at the tale anew.

A thought occurred to him as she was reaching the story's end, and when she paused to raise her cup and sip, he couldn't help asking, "Then did you have some equivalent to Cui Ren Ma? She was a fell creature who sucked the marks from our flanks and would've taken over the world had Bomu not—"

"Tirek!" Twilight sputtered, but, Yue couldn't help noticing, she didn't spill a single drop of tea. "You had a female Tirek here?"

Once again, Yue started the story from his point of view only to find himself sitting spellbound as she continued, his heart pounding to think of this demure and well-spoken young mare tangling with a monster as horrific as Cui Ren Ma.

It was then that a part of his mind began whispering that she had to stay, that she could never go, that he didn't want to continue another day without this beautiful, amazing pony in his life, but he pushed that part as far from his conscious thoughts as he could. This was neither the time nor the place—even though the scents of the moonflowers in the garden below only highlighted Twilight's intoxicating aroma; even though the night's quietude wrapped her quirky but gentle voice while she narrated the most spine-tingling of events; even though she was the impossible pony he'd secretly desired for years, a female Bomu alighting from the shores of dream to recline in perfect physical splendor upon his balcony.

But she was not for him, he knew. Like so much else is this world—true equality with his brother, for instance, and anything more than a glancing fondness from the ponies of Qi Ma Shu—this Princess Twilight Sparkle was not for him.

But still he sat drinking her in while she recounted this Tirek's final moments, her friends and someone she called Discord—obviously the counterpart of that annoying she-beast Be He Luan—finding strength in weakness the way Bomu always did.

Silence fell over them then, but it was warm instead of awkward, and Yue drank that in, too. Until— "Yue?" she asked, and he started back, realized he'd been staring directly into the velvet depths of her eyes for he didn't know how long. "I don't mean to be rude, so please tell me if this is none of my business, but, well, we've had so many other parallels that I...I have to know." She reached a hoof past the stove and touched Yue's pastern like a butterfly landing. "A thousand years ago, my world's Princess Luna let her own darkness overwhelm her and—"

Yue couldn't stop a gasp, couldn't keep from curling his hoof to close around hers, couldn't tear his gaze away from her no matter how much he wanted to.

"It's okay," Twilight said quickly. "She's all right now, and I know you are, too. You've been a wonderful host, and I've loved every minute we've spent together. I'm only bringing this up because—" Her hoof curled over his as well. "Princess Luna had constructed a nightmare she called the Tantabus so she could punish herself for deeds the rest of Equestria had already forgiven her for." Her grip tightened, stronger than Yue had expected. "You don't have one of those, do you?"

"I— It— The Meng Bian Zi." Again, he couldn't've lied to her if he'd wanted to. "It got away from me, but Bomu and the others—every pony in their home town of Xiao Ma Cheng, in fact—they helped me, showed me how to...how to accept that I was no longer—" His vision blurring and his cheeks growing damp, Yue saw water brimming in Twilight's eyes—

And a bell appeared clattering above him, its tone sharp and shrill and making Yue wince. "Ah." He poked the bell with his magic to silence it, grasped for a napkin, and dabbed his face. "That would mean we have fifteen minutes to return to Bomu's mirror." He took a deep breath and let it out with a quiet laugh, a lightness in his chest that he hadn't felt in ages. "Despite the soggy ending, Twilight Sparkle, I thank you for your visit. I hope—" His voice cracked, but he pushed on regardless. "I hope you'll consider returning some time."

"Of course I will!" Her wings flared, and she rose to all fours. She didn't let go of his hoof, though, her strength again surprising him as she pulled him up. "I make it a point to visit my friends as much as possible, and you, Prince Yue Liang, whether you like it or not, are now one of my friends!" She giggled, and Yue found himself wishing she might continue holding his hoof into the foreseeable future.

"And besides," Twilight was going on, "I still need to meet your brother and all Bomu's friends and, well, let's see: I'm guessing Bomu has a sister who's married to the alicorn prince who took over the northern kingdom—what did you call it? Jing Di Guo?—after you all defeated Queen You Yin Ying." A little scowl creased her forehead. "I just wish Luna had told me about this project of hers before tonight. I'll need to review the specifications to see if this is the sort of mirror universe where I can meet Bomu without causing total protonic reversal." Her face brightened. "Or maybe you know? Can I pick your brain on the subject?"

With another laugh, Yue turned for the door leading back into his quarters. "I, too, only learned of all this tonight. Long ago, our court sorceress, Xing Xuan Wo, was wont to experiment with mirrors, I recall vaguely, but it wasn't a sort of magic I was interested in."

"Odd." Twilight fluttered to his side, and they moved out into the dimly lit corridor. "Everything else in our universes has been so parallel." She blushed again, and Yue had to stop himself from leaping into a quick loop-de-loop at the sight. "I mean, you know, other than the whole reversed genders thing. So what's so different about mirror magic? Why have you never had any, and why was Luna working on it in my universe while Bomu was working on it in yours?"

Having no answer, Yue merely shrugged. A tiny ripple of uneasiness started tugging at him, though, and he picked up his pace just as Twilight picked up hers. Quickly taking to the air, they swooped through the hallways into the depths of Man Pao Cheng where Xing's old workshop lay.

Rounding a corner and seeing that the doorway to the lab was dark made Yue's uneasiness increase, and he flapped his larger wings to pass Twilight, landing just ahead of her in the musty stone room. The mirror still stood in its place, but the silvery glow it had emitted was gone: only their reflections in the semi-darkness looked back at him, Twilight's becoming more and more concerned.

"Are we early?" she asked, but before Yue could check, the second magical alarm he'd set earlier went off, the bell's clattering making him wince again; he smacked it with his horn, and it fell silent, not a single sound suddenly anywhere in this entire part of the palace.

"I—" Twilight started across the room as gingerly as a cat crossing a damp meadow. "What—?" She reached the mirror, held up a hoof, and moved it forward, Yue holding his breath.

Her hoof met the image of itself coming and stopped, the surface not budging an inch.

"What—?" Twilight said again, and the helpless expression she turned toward him roused every protective instinct in Yue's soul. "What's going on?"

---

She tried several spells that she said she'd devised when working with other mirror universes, but Bomu's mirror continued to do nothing but sit silently. Yue could smell her frustration mounting, so he touched her shoulder and asked if the mirror would be safe to move.

Panting slightly, the tip of her horn a white-hot ember, she nodded. "I can detect a fair amount of residual magic in this room, but none of it seems to be connected to the mirror."

"Very well." Yue lit his own horn and sent out a blue summoning sphere. "I'll have the guards take it to my laboratory. I have a few grimoires and assorted magical books, and all the libraries here in Man Pao Cheng are at our disposal, too, of course."

"Bomu's library." Bits of that lost look still flitted about the edges of Twilight's face, but just about the edges. "I'm guessing he has a castle out in the equivalent of Ponyville?"

"Jiao Qing Li Palace in Xiao Ma Cheng," Yue said, not sure if he was still capable of feeling surprise that she knew so much about their lives. "Any notes he made will be there." And because he couldn't stop himself— "What do you think happened? Did the spell malfunction? I'm not getting any aroma of material burnout, so it can't be that the mirror cracked, but magical feedback always makes my hide tingle, and I'm not—"

"Please, Prince Yue." She rubbed the space between her eyes. "Let's not conjecture in advance of the facts. Also, I...I need to start making some check lists as quickly as possible."

"Of course." Knowing Bomu, he should have guessed; reaching through the spaces between space to his workroom, Yue pulled a blank notebook and a quill from storage and materialized them in front of her.

"Thank you," she said tersely, and she was still writing in it when the guards arrived. Giving them their instructions, Yue gently herded Twilight along after them, her head down and her pen jotting notes the whole time.

The clock above the fireplace in Yue's workroom was striking midnight as they entered: an hour since the mirror should have opened, and it hadn't given so much as a crackle. Yue thanked the guards, dismissed them, turned to Twilight and asked, "What can I do to help?"

A faint smile pulled her lips, and she looked up from the book for the first time, about half the pages filled with a very Bomu-like scrawl. "Don't take this the wrong way, Yue, but I think I'd be more comfortable right now if you went about your business." She raised a hoof when he opened his mouth to complain. "If you're anything like Luna, you have duties you need to see to each night, and I've been keeping you from those duties." The way she looked around the room made Yue nervous, but she nodded instead of frowning. "I'd say there's enough here for me to get started, so do what you have to do, and I'll do the same."

Wanting to argue with her, he instead found that he couldn't. "Can I have the kitchen send anything up?" he asked after silently sputtering for a few moments.

"Anything but quesadillas," she muttered, making notes again in the book.

He blinked at her. "What?"

She waved a hoof. "Two flat disks of cooked corn meal or wheat paste served with melted cheese between them." She shuddered.

Yue did some more blinking. "I've never even heard of such a thing!"

Twilight's pen skittered to a stop, and the huge smile she turned toward him made his heart leap. "Yue, I'm liking this universe more and more."

He left her scratching away at the book and launched himself into the dreamscape in the hopes that some nightgaunts or other bogeys might be lurking about for him to vent his frustrations upon. But the turmoil that flew through the aethersphere ahead, around, and in his wake—of course he wanted Bomu back, but he just as surely didn't want Twilight to go—seemed to drive the usual gibbering monstrosities into hiding. At least that meant he could get back to the palace more quickly, and he did just that, stepping from the night's shadows to the corridor outside his workroom only three hours after he'd left.

Inside, he had to stop and stare, the place hardly recognizable. Twilight seemed to have dismantled all his furniture and rebuilt it into a giant wooden, metal, and granite framework that surrounded the mirror and changed shape, he was certain, every time he glanced away from it. All his meticulously organized books had been moved into a dozen piles scattered across the floor, and Twilight herself stood before the mirror with her whole body glowing, the tip of her tongue curled out to touch her upper lip and sweat dripping from the edge of her mane.

Having seen Bomu in this state more than once, Yue entered softly and sat by the door to wait. She held the pose for some minutes longer, but then her horn sputtered; with a snarling sort of grunt, she wrenched herself sideways, the place where she'd been standing marked by four smoking hoofprints etched into the stone.

Forcing his jaw not to drop, Yue conjured up a glass of water, moved quickly to her side, and offered it to her.

She nodded as if in thanks, grabbed the glass in her own magic, and swigged down its contents. "It's impossible!" she said, tossing the glass aside: Yue caught it in his magic before it could hit the floor. "I mean, over the years, I've not only studied Starswirl's methods, but I've transgressed several of the limitations he himself declared to be inviolable! But that mirror—!" She waved a shaking hoof at it. "It keeps turning back on itself, every trail I follow leading me right back to where I started! I don't know if I want to collaborate on a series of treatises with this Bomu of yours or kick him in the head as hard as I can!"

Yue nodded. "You're not alone in feeling that way." Unable to stop himself, he draped a wing around her, her shoulders as solid under her smooth hide as stone pillars. "I've a room you can use to get some sleep. In the morning, I'll introduce you to Tian Shang, then we'll head to Jiao Qing Li Palace and see what we can find in Bomu's notes."

For another moment, she might as well have been a statue, but with a sigh, she softened all at once and slumped against his side, every one of Yue's nerve endings lighting up like a sky full of stars. "I'm sorry," she murmured. "But I just...I just don't understand what's going on..."

"You will." He wanted so much to stroke his feathers along her back, but he knew that if he started, he would never stop. "You'll open the gate and step through and all will once again be well." Fortunately, he was speaking softly because he didn't feel able to put much conviction into the words.

He felt her nod; they rose together, and he guided her to the guest room across the hall. She clambered into bed and dropped instantly to sleep, Yue barely trusting himself to pull a blanket over her before he threw himself out into the hall and rushed through the last few tasks he'd had scheduled for tonight before Bomu had thrown his entire world into such an awful and wonderful state of madness.

At dawn, he arrived at Tian Shang's balcony just in time to lower the moon, his elder brother not saying a word till the sun was rising steadily into the warm blue of a summer morning. "Rough night?" Tian asked then.

Yue had been thinking for some hours about how best to bring Tian up to speed on the situation, but nothing had occurred to him except— "Bomu," he said simply and gestured for his brother to follow.

They winged across the spires of Man Pao Cheng Palace, and Yue led the way to the room where he'd left Twilight sleeping. "I can't prepare you for this," he said quietly and pushed open the door.

Dawn's golden light washed through the drawn curtains, Twilight relaxed in sleep and even more beautiful than Yue remembered. "That's not Bomu," Tian rumbled softly. "And yet...she is, isn't she?"

"Exactly." Yue told Tian of the night's events—as much as he understood them himself, at least—and finished just as Twilight began stirring.

Tian placed his shoulder against Yue's chest, pushed him out into the hallway and followed, closing the door behind them. "Rule number one, little brother." Tian tapped the tip of his horn against Yue's. "A gentlecolt knocks before entering a mare's boudoir, especially when that mare is an unaccountably long way from home."

He gestured to the door. Yue blinked at it. Tian rolled his eyes, raised a hoof, mimed knocking, then pointed at the door again.

Unable to stop his blush, Yue stepped up and rapped on the door. "Princess Twilight? It's Prince Yue. Are you—?"

The door glowed purple and slammed open, Twilight standing there with wide eyes. "Then...it wasn't a dream? Everything really—?" She stopped, her jaw dropping, and Yue realized that she was looking past him at Tian.

Glancing over his shoulder, Yue couldn't help but see his brother with new eyes: a tall, broad-chested, snow-white stallion, his mane and tail flowing with the sky blue and sunburst gold of a cloudless morning, his blonde mustache and goatee as carefully trimmed as always. He bowed his head and spoke in that resonant voice of his: "Princess Twilight? I'm Tian Shang. I'm sorry that your first visit to Qi Ma Shu has proven to be problematical. Rest assured, we will provide any and all assistance we can muster toward helping you resolve this situation."

A tiny flare of the old jealousy ignited in Yue's gut, but he swallowed against it easily enough. It wasn't Tian's fault that he was perfect in every—

A bark of laughter rang through the hallway, and Twilight clapped a hoof over her mouth. "I...I'm sorry, Your Highness! It's just that—" Her grin grew huge and infectious. "I've got to get that portal fixed so Celestia can meet you!" She turned to Yue, and he was sure that her eyes lit up in a way they hadn't while looking at Tian. "So! Breakfast, then Bomu's castle: is that still the plan, Yue?"

---

Breakfast was wonderful, Tian sitting back with that half-smile on his face and asking far fewer questions than Yue would've expected. The several hours of sleep seemed to have agreed with Twilight, too, her namesake sparkle returning as she laughed and exchanged more stories with Yue all through the meal. They left immediately afterwards for Xiao Ma Cheng, Twilight spreading her wings and taking off before Yue could even suggest sending for a chariot.

It had been some time since Yue had flown during the day, but gliding along beside Twilight, he couldn't help but admire the way the sunlight embraced her just as surely as the moonlight had last night. Not that he was staring at her the whole way: he wasn't that tone-deaf when it came to mares. Not that he'd had many lovers despite the centuries that he'd—

And he reined in that train of thought so quickly, he was surprised he didn't knock himself sideways out of the sky.

They passed the time, though, comparing landmarks, largely similar between here and her Equestria, except, of course, for the peculiar names she had for everything. This led them into a lively discussion about naming conventions, and Yue would've happily continued flying all the way into the depths of the Chang Zi Zai Forest if Twilight hadn't gestured to the turrets of Bomu's palace off to their left.

Flying over the outskirts of Xiao Ma Cheng, Yue noticed Twilight becoming quiet. "Ponyville," she muttered. "The whole town..." She brightened then, and he saw she was looking at the market in the village square, a familiar orange stallion in a battered hat calling out to passers-by in his baritone drawl about the virtues of introducing more apples to their diets. "Oh, now, this I've got to see!" Twilight practically squealed.

"Twilight," Yue started, but she was already diving; Yue gave a flap and caught up with her just as she landed.

"Well, now!" the stallion said, pushing back his hat and turning with a grin. "Morning, Bomu, Yue. Can't recall the last time I's seen either of you up this...early..." His grin began wilting, his forehead creasing.

Yue stepped forward quickly. "Ping Guo Jin, this is Princess Twilight Sparkle. She and Bomu are, umm..." No coherent way of finishing that sentence came to him.

Fortunately—or unfortunately, now that Yue thought about it—Twilight's tongue seemed less tied. "We're doppelgangers," she said, hopping in place, her grin growing as Ping's vanished. "Your Prince Bomu opened a path through a magic mirror to my universe, and he's visiting there while I visit here!"

Ping blinked. "Uh-huh." Tipping his head back, he shouted in a voice that smacked Yue as hard as a bucketful of cold water, "Hong!"

"Huh?" a scratchy voice asked from above, and a rainbow streak spun down to become a sky-blue stallion standing beside the apple cart. "What's up, Ping?"

"Don't gimme that!" Ping aimed a shaking hoof at Twilight, the princess's grin somehow getting even wider. "Did you put Bomu up to this? 'Cause it's a prank stupid enough to have your fat hoofprints all over it!"

"What?" The pegasus blinked, then stared.

Yue sighed. "Hong Rui Qi, this is Princess Twilight Sparkle."

"Well, now!" Hong brushed at the stripes of his unruly mane. "A lady Bomu, huh? And how're you doin'?"

Which was just about enough of that, Yue decided. But before he could externalize the thunder and lightning jabbing and growling inside him, Twilight's braying laughter broke like a wooden plank across his back. "Oh, my gosh! Rainbow is gonna die when I tell her about this! Just plain die!"

Glancing over, he saw Twilight clutching her sides and stomping the ground, the citizens of Xiao Ma Cheng starting to notice. "Uh," Hong said, his ears flat against his head. "Prince Yue? What...what...what—?"

Once again, Yue began explaining, a crowd growing around them, and by the time he got to the end, Twilight had recovered enough to help. "So, wait," Lin Lang said, the tailor's eyes darting back and forth between Yue and Twilight. "Then Bomu is trapped in this other universe?"

"Not trapped," Twilight said, her wings bristling. "Nopony's trapped anywhere! It's just that mirror travel can be really tricky! I mean, more than once, we've had to break all connection between our universe and another before everything collapsed and destroyed both!"

Lin Lang gasped. Beside him, Po Yong Xi pressed his front hooves to his snout, the veterinarian's scent even saltier with fear than usual, while Pin Qi Bing's tangled mane drooped around his shoulders like a strawberry waterfall.

Yue cleared his throat and spread his wings. "Not that there's any danger of that happening in this case!" He added a touch of the Man Pao Cheng voice so his words would carry to the whole crowd. "Prince Bomu is undoubtedly working with their Princess Luna just as Princess Twilight and I are working together here! But for now, in the very shadow of Jiao Qing Li Palace, let's extend the hoof of friendship to our visiting princess and welcome her to Qi Ma Shu!"

That got ears at least partially raised around the town square, and Twilight's bright smile and easy manner over the next hour or so greeting everypony who wanted to meet her reduced the tension tugging at Yue's mane substantially.

"Ding dang it," Ping Guo Jin said when the crowd had finally thinned out—and Ping had sold most of his apples, Yue noticed. "The things Bomu gets hisself into! Not that we ain't glad to have you, Princess, but I reckon we'll be shoving this into that boy's face for more'n a little while when he gets back."

"I'll say!" Hong Rui Qi rubbed his hooves together. "No hurry, though, right?" He arched his eyebrows at Twilight. "'Cause, I mean, you need anypony to show you around, Princess, just stop by my place, and I'll be happy to give you the grand tour."

Ping scowled at the pegasus. "Simmer down, there, RQ."

"I'm just saying!"

Smiling, Twilight shook her head. "No matter the universe, some things are a constant." She looked over at Yue, her smile fading. "And speaking of that..."

"Yes." Yue spread his wings again. "If you'll pardon us, gentlecolts, we have to gather up Bomu's notes."

Stepping into the castle, Yue heard Twilight gasp and saw Chang Ding padding across the vestibule with a bowl of gems covered in sugar held in her claws. Yue introduced them and began what he'd started thinking of as the standard explanation, but Twilight stomped past him with a glare on her face. "What have I told you about putting so much sugar on your breakfast?"

"Whaddaya mean so much?" Chang Ding glared right back. "That's hardly any!"

"Oh, really?" Twilight's horn glowed, and a flex of purple fire swept over the little dragon's bowl, a bubble drifting away filled with white powder. "There! That's more like it!"

The two stood snout to snout, and Yue thought for a moment that he was going to have to intervene. But then Chang Ding gave a snort and said, "You look weird as a girl."

"Well, so do you." Twilight's scowl softened. "But I'm glad Bomu has you to take care of him."

"Yeah, yeah." Chang Ding turned away with a wave of her claws. "You're lucky this sorta thing happens all the time in the comics, or you might have a hard time getting ponies to believe it."

Twilight chuckled, and before Yue could give her directions to Bomu's study, she was already heading down the hallway into the castle's East Wing. Shaking his head and following, Yue rounded the corner in time to see her turning the knob with her magic and pushing inside, but she jumped back with a cry of "No!"

In a flash, he was at her side. Everything looked the way it had the last time Yue had been here: books and scrolls stacked every which way on the shelves, the desk on the far wall by the window also covered. But now, a large metal bucket sat in the middle of the room, and the charred smell in the air told him that it wasn't dirt filling the thing more than halfway. "No..." Twilight whispered it this time. "He...he burned his notes..."

"We don't know that." Yue advanced into the room, his magic extending ahead to alert him in case—well, he didn't know in case of what, actually, but he felt it best to be prepared.

"That's all it can be." Every bit of sparkle was gone from her voice. "He knew we'd come here after the portal failed, so he put the remains right there where we wouldn't miss them. So we'd know that...that he doesn't mean to come back."

Yue whirled on her. "We don't know that!" But the tears in her eyes slapped the anger clear out of him. "Please, Twilight!" He dropped to his knees and took her hooves in his. "Bomu wouldn't do this! He couldn't! No more than you could! I mean, locking another pony out of her world so she can never return? That's—!"

"Lock?" Twilight's face uncrumpled, her eyes widening and her mouth opening. "Of course!" Suddenly ablaze, she grabbed Yue's head. "Yue! You're a genius, and I'm an idiot!" Pushing herself forward, she kissed him thoroughly and deeply before spinning away and vanishing in a crackle of purple lightning.

It took a few seconds for Yue's knees to unlock, but when they did, he leaped up, sent his magic into the swirling turbulence of hers, felt her arrive at her destination, and almost lost control of his knees again. She had teleported all the way back to Man Pao Cheng!

Not that Yue couldn't do that as well, of course. But he did have to take another couple of seconds to gather his wits, extend his focus, and whisk himself away.

He materialized in his workroom, Twilight once again standing in front of the giant structure into which she'd embedded the mirror last night. This time, though, she wasn't channeling enough power to warp the very strings of space: as Yue watched, she sent a single ball of magic up to touch the top of the mirror's original golden frame.

A circle immediately popped into being there, a circle with regularly spaced marks along the outer rim and a pointer reaching out from the center. "A timer," Yue said.

"Yep." Twilight turned to look at him, and while it wasn't a happy face she wore, it wasn't a sad one, either. "The first mirror I traveled through had a timer that only allowed it to open for three days every thirty moons."

"Thirty moons?" Yue was fairly certain he was now displaying the very same mixed emotions—how terrible that she wouldn't be able to leave for thirty moons, but how wonderful that she wouldn't be able to leave for thirty moons!

"No, no," she said exactly as Bomu so often did. She nodded to the circle. "From the amount of time that's passed since it last opened, I would guess it'll open in another 28 days." With half a smile, she cocked her head. "Looks like I'm your Princess of Friendship for the next moon."

---

Yue offered to juggle the heavens for her to see if they could trick Bomu's timer, but while she smiled broadly at the offer, she also shook her head.

They discussed with Tian Shang how to handle her presence and finally agreed to stick with Bomu's original plan: quiet and low-key. So Yue flew with her once more to Xiao Ma Cheng and announced that Twilight would be filling in for Bomu in Jiao Qing Li Palace for the next four weeks: "Think of it as a cultural exchange program," she said, once again adding to his explanation.

The village, more accustomed, Yue knew, to the peculiar than any other spot in Qi Ma Shu, readily accepted her, and stopping by every evening and every morning, he found her full of stories. "Even the map knows me!" she exclaimed two weeks into her stay. "Lin Lang, Po Yong Xi, and I got called this morning to, oh, we call it Appleoosa where I come from: I can't recall—"

"Ping Pu Cheng," he told her.

Her smile shone, and he basked in it as she told the story. That was the night she fell asleep nestled against his side, Yue draping his dark blue wing over her and vowing silently that no matter what else might happen, he would remain devoted to this pony, so strong and so gentle, for the rest of his days.

A week after that, they sat nestled together again on her balcony under a not-quite-midnight moon and shared their second kiss. "This place," she said, the hills beyond Xiao Ma Cheng all silver and shadow. "It's gotten to feel just like home." She stirred, and he looked down to see her looking back. "But the scenery is so much nicer."

Bending his neck, he met her lips rising to meet his—

And the next week, it was time for the portal to open.

He stood beside her in his workroom, the timer a mere two marks away from pointing straight up, and tried to stroke the tension from her back with his feathers. "You know why they did it," he said.

"Yes, yes, yes." She gave the base of his neck a nuzzle, her eyes never straying from the timer. "I just want to hear her tell me herself."

Yue nodded. "Before or after you kick Bomu in the head?"

She chuckled. "I haven't decided yet."

The timer gave a loud click, and the silver of the mirror whisked away like morning dew, the frame becoming a doorway into a room beyond: a room in which stood a tall, dark, lovely alicorn mare with a wing draped over Bomu Huo Hua in almost exactly the same way that Yue was holding Twilight. The two over there, however, Yue was sure, looked a great deal more uncertain of themselves...

Twilight crossed the threshold, and Yue followed, nopony saying a word until Twilight settled just inside the other workroom, Yue taking his place beside her. Then— "How?" was all Twilight asked.

Bomu glanced up at the alicorn mare—Princess Luna, Yue assumed—and she began to tell of her search for another mirror universe with a Sombra for her sister Celestia to love: "When our Sombra returned and chose to forsake the path of evil, it was for love of the unicorn Radiant Hope. I could see how this silently tore at Celestia, and I determined to alleviate her suffering. But when I cast the spell through the mirror, I found only silence until—" She looked down at Bomu, and Yue recognized all too well the shimmering smile in her eyes. "Until I met Bomu's spell coming the other direction. And he— That is, I—" Her gaze fell to the floor, all trace of a smile gone. "I'd had these dreams, Twilight, ever since you returned me to myself from the depths of the Nightmare, dreams where...where you...where I—"

"Yes," Yue said, knowing exactly what Luna didn't want to say. "Twilight and I have discussed my similar dreams."

Luna nodded. "The more Bomu and I talked through the interface, the more I knew that I had to—that we had to..." She scratched one front hoof over the stone floor.

Nuzzling the side of her neck, Bomu gave his familiar sideways grin. "And the more we talked, the more I know it, too." He laughed quietly. "Just my luck, right, Yue? The mare of my dreams, and she lived in another dimension."

Silence settled over them, Twilight again breaking it after a moment. "And?" she asked.

With a stomp, Luna gave a snort. "And we needed to maintain the balance! That was what doomed Celestia's romance with the alternate Sombra: the imbalance it caused between the universes! So for Bomu and I to be together, we...we had to...to—"

"To get us together," Twilight finished, poking Yue in the side.

More silence, then Bomu sighed. "It was the only way." His voice broke. "Luna said you thrived in adversity, Twilight, and Yue's never happier than when he's helping someone in distress. So Luna and I, we engineered the mirror, and...and..." He trailed off.

Yue was finding it more and more difficult to keep a straight face. He'd promised Twilight that he would follow her lead, however, and she was still standing there as stony as a statue.

"All right," she said after another long moment. She raised a hoof and pointed it at Luna. "But you owe us! And I mean a double date with all the trimmings! Right now! At Pony Joe's!" She leaped forward to wrap a hug around the startled Luna. "And thank you! Thank you! Thank you!"

Letting all the laughter he'd been holding in burst out, Yue leaped right behind her and scooped Bomu up in his magic. "Change the worlds for the better, I believe you said!" He spun the younger alicorn around. "It's a good thing you so often know what you're talking about, Bomu Huo Hua: that's all I've got to say!"