A Big Brother's Duty

by PingZing

Rating: everyone
Tags: Alternate Universe, Comedy, Shining Armor, Slice of Life, Twilight Sparkle, My Little Pony: Friendship is Magic, Princess Cadance
Length: 3899

When you meet an alternate version of your younger sister from the future, what's an older brother to do? Tease her mercilessly, obviously.

Shining Armor's younger sister is many things: studious, awkward, devastatingly brilliant, neurotic, and occasionally, the rebellion's unwitting premier magical researcher in the fight against Nightmare Moon.

What she is not, is an alicorn from the future.

No, this Twilight Sparkle is not Shining Armor's younger sister.

That doesn't mean he's not going to tease her mercilessly, After all, she is still Twilight Sparkle.

A side story to For Want of a Horseshoe. The events herein happen concurrently with Chapter 7. The other stories in this series can be found below.

1. For Want of a Horseshoe
2. A Big Brother's Duty <-- you are here
3. Healing

Published 2019-12-08 02:00:01 UTC
Last updated 2019-12-08 02:00:01 UTC

Giving Grief

"Don't say it."

She could hear the smile stretching across his face.

"Don't."

Nevertheless, she kept her gaze locked forward. To make eye contact would only hasten her inevitable capitulation.

"I can hear you thinking it. Don't even try to deny it."

It would be easier if he would say something. That way she could at least draw him into a verbal conflict—she'd always been better at those. Unfortunately, even a distance of one universe and several years wasn't enough to make him unaware of that fact too.

"Are the bats in the belfry?" he asked, glee coloring each word.

"I might be your younger sister, but right now I am older than you, buster!" she hissed.

"I said are the bats in the belfry?"

Twilight growled. "No," she ground out between clenched teeth, "they are roosting in a cave because a belfry would be far too noisy for a creature with such sensitive hearing."

There was the sound of a barely-swallowed snicker. "Gosh," he replied in a clearly-rehearsed cadence, "that sure is batty!"

Twilight groaned and finally turned to look. The version of her brother that called this particular timeline home was practically prancing in place, and wearing the biggest, dumbest smile that she'd ever seen on any iteration of his face.

With a sigh and roll of her eyes, Twilight relented, and allowed herself a smile at Shining Armor. "You know, my Shining is going to be furious that I let someone else have a chance at our secret time-travel code phrase before him."

Shining's grin widened. "I'm sure he'll live. After all, I'm guessing he had plenty of opportunities to tease you about actually pulling it off." At her confusion, his grin grew sharklike. He looked around, before lowering his voice and continuing, "Come on, you know what I mean. Your Royal Radiance, Lady Morning Shine."

Twilight's eyes widened and she leaped for Shining Armor. She jammed a hoof into his mouth, and looked around wildly. "Shush-sh-sh-sh!" She glanced through the open doorway she and Shining were standing in front of. Inside, Equestria's two princesses and reigning queen were sitting around a table, deep in discussion. Thankfully, none of them appeared to have noticed the scuffle outside the door. "We swore, Shining! I know that still happened in this timeline!"

He wriggled his way free of her hoof and continued grinning. "Ah? No, I recall I made a promise to my little sister. Who, I must note, is not you. Technically."

Unbeknownst to Shining Armor, Twilight's looks actually could kill--she had once spent a week patching up burned holes and wearing thick sunglasses until she had figured out how to stop—but even without that knowledge, he was still comfortable describing her glare as murderous. "Remember who cleaned under your bed when you moved out? Except, oh no," she said, holding a hoof to her mouth in feigned dismay, "I made that promise to my older brother. Who I must note," her tone sharpened, "is not you."

Shining paled and retreated. "Erk."

"That's what I thought," she said with a final glare. She inhaled deeply, then straightened up and let the breath out slowly. "Okay. Ground rules. You don't mention Lady Morning Shine, I don't tell Cadance about your Horstler magazines. Deal?" She held up a hoof in invitation to shake.

Shining Armor glanced nervously at his wife in the other room. Then, he nodded at Twilight and shook the proffered hoof. "Deal."

Twilight nodded back, and returned to the other side of the doorway and resumed what she had been doing before Shining had so rudely interrupted. Namely, ponywatching. The curious palace staff bustled about in the hallway outside, many of them passing by more often than was strictly required by their duties. Twilight couldn't blame them—she was a heretofore-unknown fully-grown alicorn. She and the leader of the rebellion against Nightmare Moon (and captain of the recently-restored Royal Guard) were standing guard in a small receiving room outside an airy, sun-drenched meeting room with enormous south-facing windows, Prench doors and a sweeping balcony. Inside said meeting room, Celestia, Cadance, and Nightmare Moon were seated at a round table, discussing the imminent transfer of power from Nightmare Moon to Celestia in quiet tones over small serving plates and cups of tea.

Celestia had tried to refuse any service whatsoever—it was hardly fair to ask the kitchen or serving staff to return to work on virtually no notice, in a palace that had been all but abandoned for years, she'd protested. They had been adamant, however, and tea and scones had happened. Nightmare Moon had just pulled the curtains enough to drape her side of the table in shadow and glowered. Night Guard Captain Rainbow Dash, meanwhile, had ignored the way Twilight and Shining tactfully remained outside, and taken up position against the wall behind Nightmare Moon.

Twilight hummed thoughtfully. "Before I go, remind me to give Raven a raise when I go home, would you?"

"What, you mean Miss Inkwell?"

Twilight nodded. "If she can resurrect a functioning palace staff after—what, three, four years?—of inaction on zero notice, I have clearly been undervaluing her."

"Well," Shining said, scuffing a forehoof against the floor, "I wouldn't say inaction, exactly." At Twilight's side-eye, he continued, "She's been acting as chief secretary for the Canterlot arm of the rebellion, and liaison between it and other arms. I'd bet she knew what was happening before you even arrived."

Twilight gave him a flat look. "She's your spymistress." Then, her eyes widened, and she slapped a hoof to her forehead. "Oh my stars, of course. I am an idiot. She practically told me when I met her, and I still didn't get it."

"What did she say?"

"Oh, I just know everything that goes on around here," Twilight said in an imitation of the secretary's measured tones. "She even winked!" She groaned and massaged the bridge of her muzzle.

"Okay, so... I know this is 'against the rules'," Shining said, making air quotes, "but I have to ask: what it is you do in your timeline? You work with the royal secretary, you're chummy with Celestia and Nightmare Moon and, well... clearly, things have gone off the rails if Twilight Sparkle," he said, framing her with his forelegs, "is an alicorn princess."

"Hey! I resemble that remark!" Twilight said, jabbing Shining's side with a wingtip. "And to answer your question... understand that I'm trying to avoid spoilers. Our timelines diverged some time ago from your perspective, but a number of things are still going to happen more or less the same way. That said... princess stuff!"

"Princess stuff," Shining replied flatly.

"You know. Diplomacy, wrangling the nobles, ribbon-cutting ceremonies, saving Equestria from looming existential apocalypse. That sort of thing!"

"Could have used some of that last one a few years ago," Shining said with a grimace.

Twilight winced. "That was how I started, actually," she said quietly.

She glanced into the meeting room. Cadance was glaring at Nightmare Moon and speaking firmly, wings bristling and tail lashing. Nightmare Moon was looking away, with shoulders hunched and forehooves crossed, a grimace upon her face. Celestia was clutching a teacup between her hooves and staring into it with a frown. Twilight looked away, and turned to Shining Armor.

"I was Celestia's personal student. Once I graduated from CSGU and started studying under her full-time, I..." she sighed. "I became a shut-in. Did nothing but study. Then, just before the thousandth Summer Sun Celebration, I found a prophecy about Nightmare Moon's return. My reward for telling Celestia was to be sent down the mountain to Ponyville. Celestia told me I was responsible for planning the Celebration, and to 'make some friends'."

Shining raised an eyebrow, and grunted. "Huh. Pretty different from my Twily. She was just a talented student at CSGU, and now she's a grad student." he said. "So, you find a prophecy about an ancient evil's imminent return and you get told to go organize a party?"

"Yes!" Twilight hissed, ruffling her feathers. "Thank you! I was furious all day. But it turned out for the best. Nightmare Moon returned that night, and I was terrified. But Celestia's advice had been good; I had made some friends. They calmed me down, helped find a way to stop her, and joined me on a crazy journey through the Everfree forest to find some ancient magical artifacts."

Shining gave her a long blink. "Uh-huh."

Twilight shrugged. "It worked. We used the Elements of Harmony on her, and it restored her to her normal self. More or less." She glanced into the meeting room. "Though actually spending time with her as Nightmare Moon in this timeline raises some very uncomfortable questions," she murmured, half to herself.

"Your Elements of Whatever feeling uncomfortably mind-controlly?"

Twilight fixed Shining Armor with a bewildered stare. "Wha—how did—you don't even know what they do!"

Shining rolled his eyes and scoffed. "Please. Ancient magical artifact that 'fixes' whoever it's used on? I've read that issue of Power Ponies. That's some real morally gray stuff there, Twily."

She gaped at him. "You did not just compare the life-and-death struggle against a powerful evil to some comic book."

He shrugged, and failed to hide a grin. "If the horseshoe fits..."

She cuffed him with a wing. "You are the biggest nerd! And this is me saying that!"

"Ow!" he yelped, snickering. "I mean, on the one hoof, I'm a little jealous that things worked out in your timeline. But... come on! It's like you lifted that story straight out of the Y-Ponies." He held up a placating hoof before continuing, "I know, I know what you did was real. But you have to admit that it sounds pretty crazy! I mean, look at you right now. You're literally visiting from the future! I'm pretty sure the only reason I'm not freaking out right now because I'm used to the ridiculous premises from reading all those things. It's just like," he rolled a hoof and paused, considering, "well, a real-life comic book."

Twilight lay down on crossed forehooves, covered her head with her wings and groaned. "On one hoof, I have so much ammo for my version of you when I go home. On the other hoof, I think this conversation is doing permanent damage to brain."

"You could always go in there, instead," Shining said, nodding at the meeting room.

Twilight peeked out from underneath a wing and grimaced. "Ugh, no. I think I'm almost done meddling here, and I'd really rather not do so any further. I feel like if I got involved now, it'd be like influencing the control group in an experiment."

She was met with a raised eyebrow as Shining Armor leaned against the doorframe. "Aaaand what you've been doing isn't meddling?"

Twilight uncovered her face and stood. "Oh, no it absolutely is," she admitted, her tail lashing once. "I've tried to keep it to a minimum but, well..." she gestured, vaguely indicating herself and everything around her. "And for what it's worth, I am sorry that you all suffered for so long. I bear at least some of the responsibility for this," she said, grimacing and pinning her ears back.

Shining Armor acknowledged her apology with a nod. "Oh? How's that work, anyway? Time-traveling and all that?"

"What do you mean?"

"Well," Shining said, shrugging, "you keep talking about 'my timeline' and 'this timeline'. So, are we talking about a form of time travel where the grandfather paradox isn't an issue?"

"Oh!" Twilight said, laughing. "Definitely. This isn't a closed loop. I'm not actually from your future. This timeline got knocked off the rails about ten years ago. Which was kiiiinda my fault. Kinda not."

Shining Armor raised an eyebrow.

"Because my student came back in time to try to prevent me from ever stopping her evil plan—this was before she became my student, obviously—and altered the course of history. I followed her back to try to stop her, but it didn't work. When I came back to my present, everything was different. Nightmare Moon had won, and eternal night had fallen over Equestria. That was about... oh, two weeks ago? From your perspective."

Shining Armor's eyebrow developed a twitch.

"Couldn't let that stand, so I went back into the past again. Took a couple tries, and a few more less-than-ideal versions of the present before I was able to talk my student down, and convince her to stop. We head back to the restored present, about ten years pass, I find out that all those alternate timelines are still around, and now, here I am!" she finished, smiling brightly.

Shining Armor furrowed his brow and slowly tilted his head to the side. "Okay. And you found a way to travel here in a way that didn't influence your timeline?"

Twilight nodded. "Untangling the chrono-matrices from each other was the hardest part of writing the spell formula. It wound up being a three-stage cast sequence, and each—" She noticed that Shining's eyes had begun to glaze over. "—well, the point is, we did it!"

Shining paused for a long moment, and slowly nodded to himself, brow furrowing further. "Twilight?" he asked quietly, all levity now gone from his voice. "Can I ask exactly how you became an alicorn? I mean... you remember all the old myths. About how alicorns only appear when things are getting bad. Like... Cady gets her horn, and only a few years later, Nightmare Moon reappears. And I... I think about my little sister, the shy, brainy grad student... and then I look at you, and I wonder how she gets there. What happened in your timeline that needed a brilliant bookworm to become a dimension-hopping immortal?"

Twilight's expression had fallen as Shining spoke, and she was now frowning deeply. She stood up and walked a few steps away and stood in silence for a moment. She turned to face Shining directly, and he had to bite back a gasp. If not for the familiar shade of violet, he would have sworn he was looking into Celestia's eyes. Within them were the same depth of wisdom, serenity, and unshakable certainty that he recognized in the solar princess's gaze. He swallowed heavily.

"Like I said, Nightmare Moon was only the beginning for me. Afterward, Equestria faced a number of threats, even before I became an alicorn. Some of them actually apocalyptic in nature. I still have nightmares about a lot of them." She took a deep breath before continuing. "But. I've never been alone. I have the love and support of friends and family. I get to keep those important to me safe, and do meaningful work." Her gaze softened as she continued, "I know you want to keep your sister out of harm's way—"she glanced away and rolled her eyes, "—my Shiny did exactly the same thing when he found out about the whole Nightmare Moon thing. And the thing with Dis—uh, the next thing. And, I guess, all the other things, too."

Same old Twilight. Shining Armor raised an eyebrow, and gave his tail an expectant swish.

Twilight coughed and attempted, with only moderate success, to resummon her earlier gravitas. "My point is that I'm happy and have no regrets. Even about the terrifying parts. I'd bet that your sister has the same capacity to do similar things. I don't think my transformation came about because I was chosen by Harmony, or because," and her voice grew dramatic, "a champion of the light was needed to stand against the darkness!"

Shining matched Twilight's self-deprecating eyeroll with one of his own. "Okay, I take your point. Imagining little Twily going through all that still makes me uncomfortable though," he said with a shrug.

"Well..." Twilight paused, "if it makes you feel any better, I don't put any stock in those myths. Not after my transformation. It was pretty much an accident. And I can think of one more example that pretty firmly debunks the whole 'alicorns are harbingers of dark times' myth," she said, directing a fond smile at the occupants of the meeting room.

Brow furrowing, Shining Armor followed Twilight's gaze and found himself looking at... Cadance? His frown deepened. "What do you mean? She ascended just before Nightmare Moon's return. It would match up with..." He trailed off, as he saw Twilight's smile continuing to grow.

He looked back at Cadance. Then again at Twilight, whose smile had graduated from merely amused to gleeful.

The bit dropped. Shining's eyes widened, and his ears folded back.

He looked back at Cadance. A very pregnant Cadance.

His head whipped back toward Twilight. "No."

Twilight just gave a smug smile and turned her nose up. "Sorry, Shining. Spoilers."

Shining gaped. "You can't just dangle that in front of me and then clam up!"

Twilight's smile grew fond, and she giggled. "I'm sorry, that was cruel of me. I really shouldn't even hint at things like that—I have no idea if what happened in my timeline will happen here."

"But... you weren't serious, were you? We didn't really have an alicorn foal in your timeline, did we?"

Twilight just winked, and mimed zipping her lips shut. She trotted a few steps away, and made a show of looking out of the receiving room's small window. Behind her, Shining sighed and lashed his tail once. When it became clear he was going to get nothing further from the alicorn, he resumed the default stance of guards everywhere. Eyes forward, expression blank, posture straight.

Eventually, Twilight broke the silence. "Shining?" she asked quietly, "What's your sister like?" At Shining's silence, she continued, "I think about the pony I was before Celestia pulled—yanked, really—me out of my shell, and she... wasn't a pony that handled change, much less total societal upheaval, well."

Shining gave a thoughtful hum, as Twilight turned to face him. "Well... the first few weeks were bad everywhere. When the sun disappeared..." he trailed off. He joined Twilight at the window, and looked out across Canterlot shining brightly in the early-afternoon sun. "It still doesn't feel real to see it like this again." He sighed. "To answer your question, she's... okay. After all the chaos at first, life more or less went on as usual. She went right back to work on her doctorate in applied arcanics. But she won't talk about anything to do with Celestia or Nightmare Moon. She'll just change the subject, or leave the room if she has to."

"Does she know what you've been doing?"

"No. She thinks I'm just captain of the city guard. I did consult with her occasionally on some spells we needed, but she never knew why. I was afraid that if Cady or I got captured, and they found out she'd been involved..."

"Of course." Twilight hesitated for a moment before continuing. "You know that if you'd told her, she would've wanted to join up instantly, right?"

Shining eyed her. "Think so?"

"Definitely. And... a word of advice. She's going to find out that you and Cadance were the leaders of the rebellion. Make sure she finds out from you. Tonight, if possible, after the announcement."

Shining winced. "That's not going to be a fun conversation, is it?"

"Probably not!" Twilight said with a cheery grin.

The sound of scraping chairs came from within the meeting room, and the volume of the conversation grew from a distant murmur into distinct words. Twilight stayed by the window, while Shining made his way back to the doorway.

He arrived in time to meet Cadance as she waddled out of the meeting room. She gave him a brief hug and a smile before moving to the side, to make room for Celestia and Nightmare Moon, who were still deep in discussion. Rainbow Dash trailed at a discreet distance, and gave Twilight a nod as she followed her queen out of the room. Twilight returned the nod and remained at a polite distance to give Shining and Cadance's whispered conversation some modicum of privacy. Eventually, they drew apart, and Cadance turned to Twilight and beckoned her over.

"Sunshine, sunshine...?" she prompted, uncertainly.

"Ladybugs awake," Twilight responded with a wink. "But you don't look much like you're up to clapping your hooves or doing a little shake, if you'll forgive my saying so," she said, eyeing Cadance's swollen belly and the dark circles under her eyes.

She laughed, and turned to give Shining a quick peck on the cheek. "You were right. Definitely Twilight." She turned back to Twilight. "I saw you lurking in the back when we came in, and I said to Shiny 'Oh my goodness, she looks just like Twilight!' And then we saw your cutie mark, and, well..." She giggled. "Anyway! I hear we have you to thank, at least in part, for Celestia's return and Nightmare Moon coming to the table to talk."

Twilight shuffled her hooves and looked away. "Well... I'd say I just sort of moved the timetable up a little, that's all."

Cadance reached up and wrapped her hooves and wings around the taller alicorn. To Twilight's surprise, Cadance was trembling slightly. Twilight returned the hug, squeezing as tightly as she dared. "I don't know if we could have made it much longer. Thank you," Cadance said, voice thick with emotion. Cadance held on for a moment longer before taking a deep breath and drawing back. She held Twilight by the shoulders for a moment and gave her a watery smile before letting go.

The trio spent a moment collecting themselves, sniffling, and sharing smiles. Finally, Shining Armor managed to speak. "Wait until you hear the rest of her story," he said, "It's a real tale."

"I'll bet!" Cadance chirped. "And speaking of tails, Twilight, I love your mane and tail. That orange tinge you have at the edges is so pretty! In fact..." she said, drawing back and brining a hoof to her chin in thought. "They remind me of something... oh!" she exclaimed, stamping a hoof against the tile floor. "You look just like those old pictures of you drew of Lady Morning Shine!"

There was a yawning, sucking silence as Twilight's expression froze, and she slowly turned to face Shining Armor.

"Shiny?"

Shining Armor gulped, and weighed his odds of escape against a powerful alicorn from the future and—worse—his wife. One of the most important things he'd learned in the Royal Guard was when to give ground.

"Yes, Twily?" he squeaked.

"I have a wonderful story to share with Cadance!" She turned to Cadance with a bright smile on her face, and ushered her toward the hall. "Has Shiny ever shared the story of when he moved out for Royal Guard training?"

Cadance shot a sly grin toward Shining Armor as she followed Twilight. "You know, I don't believe he has!"

Twilight's eyes flashed. "Well then!"

Author's Note

When Twilight returned home, she paid a visit to the Crystal Empire for lunch with Cadance and Shining Armor.

"Cadance, do you remember those pictures I drew as a foal? Of... oh, what was her name?"

"Oh, Lady Morning Shine! Oh those were adorable! Shining showed them to me!"

Shining choked on his drink. Twilight grinned. Gotcha.

"There's a funny story there, actually..."

And I've published a small retrospective blog post, that talks about possible upcoming stories.