Dear Prince Bómù—
Twilight smiled as she always did at the little notebook, her quill pen's two shadows wavering over its final page in the light cast by her horn and by the candle on her desk. Originally, she'd planned on writing these notes to Celestia as a way of keeping herself connected to home, but the more she'd thought about it in the days following Tiāngǒu's defeat and Yúhuī's return to the palace as Tiān Shàng's student, the more appropriate it had seemed for her to buy a diary of the sort she always kept in her desk at home, fill it out, then leave it in the drawer for Bómù to find after he got back...
According to the mirror gate's timer, the way between our universes will open once again in less than an hour. The pages of this notebook will tell you many of the adventures I've shared with our mutual friends here over the past twenty-seven days—
Though not all the adventures, she had to admit with another smile and a certain amount of warm tingling. She'd heard Rarity talk about how a lady didn't kiss and tell, and now that Twilight had done some kissing of her own, she found herself agreeing entirely.
—but I look forward to meeting you in person to review the many notes I'm certain you've made concerning your stay in Equestria.
She hesitated a moment, then wrote:
Your soon-to-be friend,
And signed it. She'd almost given in to her first urge and written "Thank you, thank you, thank you, thank you" over and over across the remaining space at the bottom of the page. But this was a document for posterity, she couldn't forget, and—
"Twilight?" a hesitant voice called from the doorway, and Twilight glanced over to see Dào Gōu peering in. "You busy?"
"Just finishing up." Flexing her magic, Twilight tucked her quill into the inkwell, pulled open the drawer of Bómù's desk, and set the diary into the empty space where his should've been. "But you should be in bed, Gōu Gōu." With a grin, she wagged a hoof at the little dragon. "I don't want Bómù thinking I let you stay up till the middle of the night."
"I'm going, I'm going." Dào Gōu's annoyed look faded almost immediately. "I just...what you said at Bǐng's party earlier, how it wasn't really a going away party 'cause you're just gonna be in the universe next door and can come through the mirror anytime after you show Bómù how to fix it..." Dào Gōu's claws scritch-scratched the crystal floor as she shifted in place. "Did you mean that?"
"Well, of course!" Twilight couldn't keep from spreading her wings, hopping over, and giving Dào Gōu a hug. "I've had a wonderful time here this past moon, and my examination of Bómù's spell shows it to be remarkably stable for his first try at a mirror portal. Once we get the timing issues worked out, it shouldn't be any problem to maintain the connection. You could even come over and meet Spike!" Taking a step back, Twilight touched Dào Gōu's nose. "Though I don't know if any one universe could survive with both of you inside it."
"Ha, ha." Dào Gōu folded her arms, then started running her claws up and down along her shoulder scales. "But really, I— I mean, Bómù's great, and it'll be great having him back, but— Ever since Jīng Yíng Jiă married Prince Jié Zòu and moved up north, I...I've kinda missed having a sister, y'know? So these past couple weeks've been—" Her usual hot, dry scent grew humid in Twilight's nose, and she cleared her throat. "Anyway, I'm gonna make you your own bedroom down the hall so you'll have a place to stay any time you want to come visit."
Twilight had to clear her own throat before wrapping Dào Gōu in another hug. "Thanks, Gōu Gōu."
This time, it was Dào Gōu who pushed away. "And don't tell Bómù I let you call me that! 'Cause no one but him can call me that! And he can't, either!" She turned and stomped off down the hall as loudly as her little claws could manage. "Yeesh! Some ponies!"
A deep, wonderful chuckle behind her sent warm shivers rustling up Twilight's spine; she smiled, took a breath, and turned to see Mèng Huàn sitting with his legs tucked under himself on the balcony outside the open double doors, the moonlight shining soft and silver in his coat. "Might one be so bold as to say that you seem to have made some friends during your stay?"
And as much as she wanted to fly to him for a more interesting sort of hugging, she instead put on a semi-annoyed expression. "You mean the kind who spy on me through my bedroom window?"
Mèng Huàn blew loudly through his lips. "Amateurs! Those of us who really care for you spy on you in your dreams."
At that, she couldn't keep from jumping across the room to taste those lips, his perfect wings taking her and holding her. "You're lucky you're so cute," she said when she could. "Because otherwise, you'd be pretty creepy."
"Well?" He shrugged, her wings riding up and down where they rested on his shoulders. "I am a fiendish creature of the night, after all."
"Speaking of which—" She tapped his chest. "I stopped by Fēng's cottage this afternoon before Bǐng's party to check on Tiāngǒu. He's getting along well with the other puppies, but I...I'm pretty sure he still remembers everything that happened." She couldn't stop a shiver. "We'll need to work extra hard to make sure he doesn't grow up just as mean this time as he did the last time."
"Indeed." Mèng Huàn cocked his head. "Perhaps I should consider adopting him. Wēi Fēng Fǔ is an excellent veterinarian, of course, but I'm led to understand that a permanent home is much more conducive to a youngster turning out right."
Twilight blinked, the idea feeling absolutely right to her. "Of course! And having a pet'll be great for you, too! Why, Luna's opossum Tiberius is—" Saying Luna's name made Twilight's voice freeze, her thoughts snapping back to how soon the mirror was going to open and—
And send her home.
She looked past Mèng Huàn at Xiǎo Mǎ Chéng, the windows mostly dark, the town and the woods beyond bathed in moonlight.
"Twilight?" Mèng Huàn nuzzled her neck. "Is everything all right?"
"Yes, but—" She pressed the side of her head against his. "I don't want to go."
"You're not really going." His lips found her ear, and she had to close her eyes as he gave it a little nibble, his next words coming to her as the slightest of whispers: "That's what I've been telling myself all week so I wouldn't fall weeping into my oatmeal every morning. We'll be just steps away from each other. Just steps."
"I know, I know!" Unable to keep still, Twilight leaped from his embrace and started pacing back and forth across the balcony. "But we'll still have so many tests to run on the mirror's interfacial mechanisms! And even if they are as stable as they seem to be, it'd be sheer foolishness to risk multiple crossings! I mean, the passage between the universe where King Sombra was good and Celestia and Luna were evil stayed open for more than a thousand years, sure, but only because hardly anypony ever crossed through! And even then, every time Celestia used it, it grew more and more imbalanced till the flux rate ratios finally caused it to—!"
Mèng Huàn loomed up before her and gently pressed a hoof to her lips. "You'll fix it," he said, the confidence in his voice making Twilight's heart flutter. "You and Bómù together, I'm firmly convinced, will be well on your way to solving every problem in every possible universe before the next week is out."
Smiling, she gave his hoof a kiss. "I don't know, though." She put on her best phony pout. "I'm still thinking I might have to kick him in the head first."
"Always a popular option." He stepped back and spread his wings. "Still, we do have an appointment."
Twilight nodded, and looking up at her coltfriend, she had to swallow against the tightness in her throat. Four weeks ago, the idea of being in love had rarely if ever tickled its way into her thoughts. But now?
Now she couldn't imagine living another moment of her life without this amazing pony beside her.
And if she everything went right, she wouldn't have to. Spreading her own wings, she leaped into the night sky, felt him rising with her, his magic reaching out. She met it, twined her magic with his, and together they slipped into the spaces between space.
And so it came down to this in the end.
No, not the end! Mèng Huàn could barely stop himself from stomping the floor of his workshop. This was only the beginning, and barely even that!
Standing beside him, Twilight glanced up. "Looks like it's my turn to ask," she said, turning her attention back to the mirror, the timer floating above the glass having swept its pointer nearly all the way around its entire circle over the course of the previous four weeks. "Is everything all right?"
"It is." He draped a wing across the sweet curve of her back, felt the tension there, began stroking his feathers back and forth in a way he knew she enjoyed. "I do have to wonder, however, why you're so determined to play this out in this fashion. If your theory is correct, then you know why they did it, so you've no reason to—"
"I know, I know!" She squirmed under his wing, but then he felt her shoulders relax; with a sigh, she leaned against him. "I just want to hear them say it. That's all."
He nodded, and something pinged from the mirror. Looking forward, he watched the same silvery glow come over the reflective surface that he'd seen there four weeks—and a lifetime—ago.
This time, though, the glow began to ripple, and as he watched, it whisked away like a morning dew, the frame becoming a doorway into a room beyond. That room looked very much like his own workroom, Mèng Huàn could see, and in it stood a tall, dark, alicorn mare—Princess Luna, he assumed—with her wing brushing Bómù in almost exactly the same way that he was brushing Twilight.
Stepping away from him, Twilight stomped across the room and through the portal, Mèng Huàn following her. And while nopony said a word, when Mèng Huàn met Bómù's eyes, his friend's gaze darted away more quickly than any hummingbird.
Twilight settled to the floor like a thundercloud just inside the other workroom, Mèng Huàn sitting beside her and trying very hard not to let his astonishment show. He'd thought, after all, that getting to know Twilight and coming to appreciate the wonderful differences between her and Bómù would've prepared him for meeting his own doppelganger.
But instead of the sort of distorted reflection of himself that he'd expected, he found himself blinking at a flesh-and-blood pony. Yes, she was an alicorn mare, but Twilight had gotten him used to that once novel idea, and yes, her magic crackled the air around her in ways he'd never felt before. Still, his overall impression was less of meeting his mirror universe duplicate than of meeting a sister he'd never known he had...
The silence continued to thicken, Mèng Huàn keeping his promise not to say a word, then— "How?" Twilight asked.
Bómù glanced up at Luna, and she stuck her chin out. "I take full responsibility for what occurred, Twilight Sparkle, and I'll not have you placing any blame upon—"
"Umm, hello?" Bómù raised a front hoof. "Co-conspirator right here."
"Nonsense." Luna sniffed. "I instigated the crime; therefore, my guilt is greater."
"Not necessarily." Puffing out his chest, Bómù tapped it. "Without my technical know-how, none of this would've been possible."
Luna rolled her eyes. "Please. You were at most an enabler of my—"
Twilight cleared her throat with a volume and precision that Mèng Huàn had never heard before, and the mouths of the other two snapped shut with a simultaneous clicking of teeth. "Once again," Twilight said, her own teeth clenched, "I'm asking 'how'?"
The two swallowed so loudly, Mèng Huàn could hear it. Then Luna stepped forward, her head bowed. "I began researching mirror universe magic after we all returned from our adventure in the Crystal Empire during which the love of the unicorn Radiant Hope revivified that arch-fiend Sombra and began the process of his reformation. I could see how this silently tore at Celestia: the love of her life, after all, had been the Sombra of Starswirl's now inaccessible mirror universe. So I sought to discover a mirror realm where a third Sombra might be found with whom my sister could perhaps strike up some sort of correspondence."
With a sigh, Luna raised her head. "Casting about the universes, however, brought me nothing but silence. I was almost convinced that I'd somehow fumbled the spell until—" She looked down at Bómù, and Mèng Huàn recognized all too well the shimmering smile in her eyes. "Until I met Bómù's spell coming the other direction. And he— That is, I—" Her gaze fell to the floor again, 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 you...where I...where we—"
"Yes," Mèng Huàn said, knowing exactly what Luna didn't want to say. "Twilight and I have discussed my similar dreams concerning myself and Bómù."
Luna nodded, and Bómù blushed. "The more Bómù and I talked through the interface, the more intrigued I became by him. And 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, Bómù gave his familiar sideways grin. "Just my luck, right, Mèng Huàn? The mare of my dreams, and she lived in another dimension."
More silence settled over them, and Mèng Huàn struggled not to break it. Even Twilight seemed to be wavering beside him, the storminess she'd been projecting slowly breaking up. "And?" she asked almost gently.
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 Bómù and I to be together, we...we had to...to—"
"To get us together," Twilight finished, poking Mèng Huàn in the side.
Bómù sighed. "It was the only way." His voice broke. "Luna said you thrived in adversity, Twilight, and Mèng Huàn's never happier than when he's helping someone in distress. So Luna and I, we engineered the mirror to strand you there, and...and..." He trailed off.
At this point, Mèng Huàn was finding it almost impossible to keep a straight face. Looking down, he was relieved to see Twilight finally smiling. "All right," she said. "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, Mèng Huàn leaped right behind her and scooped Bómù up in his magic. "Change the worlds for the better, I believe was the last thing you said to me!" He spun the younger alicorn around. "It's a good thing you so often know what you're talking about, Bómù Guāng Shǎn: that's all I've got to say!"