Dusk Shine's Fatal Flaw

by KeeMoo

Chapter 1 - Three Princesses

Dear Princess Celestia,

I know I promised in my last letter that I would leave my isolation in "just a couple weeks" after what had happened, but I am going to have to extend that period til the end of the month.

Spike has remained at my side within the castle and continues to be a rock for me to balance myself. He's gotten my flank in line more times than I can count and has made sure that I'm well fed. I'm definitely going to have to spoil him when things are said and done.

I've also talked his ear off to the point that I am sure that my last letter was just full of random non sequiturs. It's honestly kept me up more than the growing pains have. Regardless (and this may be wishful thinking), I feel my mind coming back into alignment. Slowly, but surely, I'll figure out just who I am.

Until then, I hope you may approve of me continuing to use this name. It feels the most comfortable and Spike's reminded me to not over think it. Besides, it would be easier legally. We will have to talk about my title, but that can come with time.

Please give my regards to my friends and condolences to Cadance. Promise them that I will do so in person at the earliest opportunity. Oh, and say, "Hi," to Luna for me. I miss our talks.

Sincerely,
Dusk Shine

. . . . .

Celestia's used her magic to roll the parchment one more time. She's read it over and over the past few weeks and was already feeling the itch to pour over it yet again. So many lines have kept her up at night. She tapped the scroll against her head a few times, pacing back and forth. Her metal shoes clanked loudly against the wooden flooring as she tried to get her bearings.

"Princess?"

"What did he mean by 'growing pains?'" Celestia said.

"Excuse me?"

The princess snapped her attention towards Mayor Mare, the smaller pony nearly falling back out the door in shock. Celestia quickly used her magic to gently right her and close the door.

"I am so sorry, Madame Mare. Both for the intrusion and the scare."

"It's not a problem at all. When I was told I had a visitor, I was not expecting the Alicorn Princess of the Sun." The Mayor dipped her head in respect before adopting a serious expression. "Is this about the castle?"

Celestia let out a sign and let her gaze wander out the window. You couldn't see the Castle of Friendship from City Hall, but she could feel the presence of powerful magic. Their magic. Magic that suddenly surged the day before.

"Not many of us noticed the barrier at first." The Mayor looked over her desk. "I had a few complaints from our pegasi about the skies around there, but the young prince has always been up to something, even before he ascended, so I swept them under the rug until his return. It wasn't until his friends came back without him that rumors began to circulate. Then word got out about something happening at the Crystal Empire."

The princess sat in silence, her mane waving in nonexistent wind and her eyes looked far away. The Mayor Mare had seen that look before.

"Celestia, what exactly happened to young Dusk Shine?"

The princess just slowly shook her head.

. . . . .

"Right this way, miss."

Cadance nodded in thanks as she left the train station. It had been a while since she had been in Ponyville. It was a pleasant little village that was home to a lot of interesting characters, but after her crowning ceremony, the Crystal Empire just took too much of her time. The last time she'd even been in this part of Equestria was to see-

Cadance quickly cut that thought out of her head before she could dwell on it. With a huff, she used her magic to affirm her transition spell and took to the Ponyville streets. Ponies milled around her as she did her best not to get in the way. It was very different than back home, where city crowds would just push pass each other like streams in a river. It was nice to be away from the corporate world and back to where families ran their own livelihoods. It was so much like the lower levels of Canterlot, where she spent so much time watching over-

'Stop.' Cadance urged herself not to get lost in thought, again. She'd been an utter mess for over a month. She's the alicorn Princess of Love and was yet reduced to a ruler barely capable of holding herself together long enough give commands to her trying nation.

Cadance felt disconnected from her body as she stopped herself in the middle of the street as two very familiar magical signatures hit her like a stampede.

She shouldn't even be here. Her people needed her, yet she's selfishly pursuing her own goals. If she pooled her magic now, then she could teleport back in a few trips before collapsing from magical exhaustion and waking up the next day. She would be out of this town and away from its horrifying implications.

She'd be away from that hideous signature, but also be away from the one she loved more than anything.

Cadance's breathing got heavier as she just stared straight ahead. If one looked at her closely, they'd see a double image as her spell began to unravel.

"High-Low, new friend that I've totally not seen before! I, Pinkie Pie, will do the thing I am very well known for and whisk you away for a happy welcome party celebration! 'Let's-a go,' as they say in Neighpon!"

In a puff of blue and yellow confetti, the two vanished from sight. Leaving a few confused residences behind.

"Looks like Pie's feeling better."

"Good for her."

Everyone went about their day after that.

. . . . .

"Are you sure, Princess?"

The hoofmaiden, a young mare who went by "Hearted," received only a glare. There was no real heat behind it, but its intention was clear. The maid had unfortunately grown very accustomed to interpreting her Highness' looks this past month.

"Forgive my questioning, but you already haven't been sleeping well. Now you're covering for your sister on top of your nightly duties? I'm worried for your health." She pleaded.

Luna, Alicorn Princess of the Moon, looked outwards into the morning sky, a glow fading from her horn as the Sun found its place. To most, she was still one of the most stunning and beautiful mares in the country, even as her mane hung low, but the hoofmaiden could only see a mere shell of the beloved princess.

She walked towards her vanity without a word. The maid was downtrodden, but got to work. They brighten sullen eyes, brush a tangled mane and don the princess in royal attire that seemed to grow looser by the day. With a finishing touch, the hoofmaiden cast a revitalization spell.

Luna stood up, fixed her posture and took a good long look at the mirror then an even longer one outside her balcony. The maid waited by the door for her to join them. When she did, the princess readied herself before giving the signal.

With a smile and gleam that would fool almost anyone, Princess Luna stepped out into the public.

. . . . .

"Which is why I stopped here first." Celestia said.

Her and Mayor Mare were talking over tea in her office. Mare had barely touched it as she just stared at the murky reflection.

"I trust you, Mare. Enough to be fully honest with the whole story. The ponies of this town may be in danger. If- if it comes to it, then I'll do everything in my power to stop it, but-"

The Mayor looked up at her friend as the princess' brave facade began to break down. With news like that, she was having a hard time just wrapping her head around it. As an earth pony, unicorn magic was already a step above her pay grade, much less the further reaches of what true masters of the craft could bring forth.

"Celestia, do you believe Dusk Shine would harm us? That he'd bring irreparable damage to the town and people he's grown to love so much? Even after what he put himself through, do you truly think he'd let anything like that happen?" Mare gave up on the tea and walked over to the window, forcing the princess to look at her. "Ask anypony in this town about Dusk Shine, Applejack, Rarity, Fluttershy, Pinkie Pie or Rainbow Dash, and while it wouldn't be all positive, I'd guarantee you that each and every single one of them would have utter trust in them."

The mayor saw the princess brighten up at her comment. For just a moment, she saw a look of pride and love that reminded her of Celestia the pony, not the princess, before that look disappeared when her gaze returned to the window.

"A lot has happened in just a few short years compared the thousand that came before it. So much of it because I refused to act decisively. Chrysalis, Discord-" Celestia's eyes narrowed. "Sombra and even my own sister were left to plan, escape and suffer over the course of those thousand years. My poor student and those innocent mares were forced into catastrophe after catastrophe to fix problems I found excuse after excuse not to handle."

Celestia abruptly turned to leave. "Not this time, Mare. My student followed my teachings to fix yet another one of my mistakes and has been left to suffer for a month too long. Whether it be to help or..." The words died in her mouth. She hated even the thought.

"Whether it be to help or handle the situation, you must act now." Mayor Mare finished. "I'll warn my messengers. If Prince Dusk Shine really is no more, then we will be prepared."

Celestia nodded. Her horn flared with a burst of illusion magic and a much smaller, cream colored earth pony stood in her place. "Thank you for your words and your time, Madame Mayor. I'll update you after everything is said and done."

. . . . .

"Are you sure she's an earth pony?"

"Eeyup."

"No horn or magic trinket hidden away?"

"Nope."

"Yeah, Pinkie's always had a knack for knowing when someone new is in town." Rainbow Dash said.

Cadance, in her true form, furrowed her brow at the pegasus as they lazily sprawled themselves across the couch in Applejack's home. The mare in question was in the kitchen nearby while Pinkie Pie was upstairs getting the others.

"But what about her seeing through my disguise?"

"You weren't disguised when you got here."

"Eeyup."

Applejack appeared around the edge of Cadance's chair holding a mug. She took it with a small thanks and stared at the warm cider within in awe. The earth pony gave a small smile before disappearing back into the kitchen. Cadance took a careful sip and felt to warm liquid nurture her soul. No wonder Sweet Apple Acres was so revered.

"What about the teleporting?"

"What teleporting?" Rainbow asked. "You two just walked in here."

"Really?" Cadance knew she was a bit out of it, but walking-several-miles-without-noticing out of it?

"You seemed troubled."

Cadance gave a yelp unbecoming of a princess at the sudden new voice. Only an instinctive use of magic kept her from spilling her drink.

"Oh, did I scare you?" Fluttershy's wings bent forward to cover her face. "I'm so sorry. I didn't mean to surprise you. I'm really really sorry."

"Darling, no need to lay it on so thick." Rarity spoke up from the stairs. She trotted over to gently pull Fluttershy's wings from her face. "It's absolutely grand to see you, again, your majesty. We haven't fully seen each other since the Crystal Fair."

"Oh, Rarity, it's just 'Cadance.' It's nice to get away and see you all, too." She turned to the yellow pegasus. "That includes you, Fluttershy. There's nothing to be ashamed of, I was just deep in thought."

"That's cool, now where's Pinkie?" Rainbow Dash asked.

"She's been working on her... hair."

"And failing!"

Pinkie Pie's abrupt appearance next to Rainbow Dash absolutely confirmed Cadance's suspicions that the pink earth pony somehow had access to some sort of greater magic. The princess felt the need to start questioning how, but couldn't bring herself to do so when she got a good look at her. The bubbly party pony still rocked the same wide grin she always seemed to have. She bounced lightly in her seat and even spoke with the exact same, recognizable cadence, but it still took Cadance a moment to equate the pony she was seeing with the one she remembered.

Cadance didn't know Pinkie Pie especially well, but she vividly remembered and associated the mare with bright pink coloring and hair as aloof as her personality. Seeing her coat, while still pink, darkened to an almost gray and her mane lacking even a single curl sent a maternal pang through the Princess of Love. It was a sensation she'd fostered ever since she took up looking after Spike while D-"

'Right.' There was an elephant in the room who didn't deserve to be ignored.

"Are we all here to see him?"

The whole house fell silent. No sounds from the couch nor the kitchen.

"We're all worried about him." Fluttershy said slowly. "It's not like we aren't used to him disappearing into his home every now and again, but with what happened-"

"Egghead's fine." Rainbow Dash interrupted. "Like she said, he gets caught up in his nerd stuff and we have to drag him out to touch some grass. If it weren't for that annoying barrier, everypony would've stop their crying already."

"Shame though." Pinkie Pie giggled. "I was this close to winning by finding a way inside after Dashie couldn't break it, but then the whole thing went kablooey."

"Kablooey?" Cadance tilted her head.

"Yeah, I bet he quit because he knew I was about to win."

"She's talking about last night, Cadance" Rarity clarified. "When the field went down and that, uh, signature started blaring."

"Signature." Cadance could feel the signatures she was talking about, especially now that she was so much closer to its source. "Wait, you can feel it, too?"

"Eeyup."

Applejack came back around the corner and took the surprisingly empty cup from Cadance's hooves. She turned and lightly prodded Rarity's horn before signaling towards the kitchen to the others.

"Yippie! Free grub." Pinkie jumped in such a way that knocked Rainbow Dash off the couch.

"Hey!" The pegasus gave chase.

"Please, don't run." Fluttershy followed the two as they went into the kitchen.

"Excuse the noise, Cadance. Would you do us the pleasure of joining us for lunch?"

Rarity didn't get a response as the princess studied the unicorn's horn or more specifically, the band wrapped around the base that Applejack had pointed out. She had the misfortune of being subjected to one of those and was confused as to why the white mare would willingly use one on herself.

"The signature." Rarity answered.

"Huh?"

"Oh, sorry, Cadance. You were speaking out loud."

The pink alicorn just sighed and sank into her chair. Between apparently walking several miles while completely unaware and speaking her thoughts without realizing, she believed she'd finally been driven mad.

"Nonsense! It's a fair question to ask." Rarity winced. "Oh, you did it, again. Moving along, I just couldn't bare that signature all night, so I donned this magic dampener that Dusk Shine gifted me to block it out. I may not be the most magically inclined, but those Elements of Harmony have a habit of boosting things like that. This dampener helps me until the effects wear off and I can comfortably control my magic.

"You used the Elements of Harmony?"

"No, not since a month ago. I felt absolutely fine up until last night."

Now that was news she'd have to process. As an alicorn, Cadance really didn't think about the signatures she felt beyond their abnormality. She had been trained in the art of sensing the signatures of other magically inclined creatures, but was also aware of how to block out signatures so that she wouldn't be overwhelmed.

As a unicorn who has chosen not to become a mage, Rarity shouldn't even be able to sense magical signatures without outside help, yet was so overwhelmed by a signature coming from halfway across town that she chose to remove her magic entirely?

Just what did that say about the signatures coming from the Castle of Friendship?

"I haven't the foggiest idea."

Cadance took a moment to look at Rarity, then at the ceiling. "I need food."

"Is that 'yes' to lunch?"

"Yes, please."

. . . . .

Midday court had progressed nicely, all things considered. There was some confusion when the guards announced Princess Luna's presence instead of Celestia's, but the noise was quelled and things proceeded. Luna had a sharper tongue and was much more blunt than her sister, but otherwise, she was well aware of the issues passed on from previous meetings.

"Next on the agenda is our continued relief for the Crystal Empire." A delegate said.

"Approved."

A small wave of mummers fill the air.

"Now, now, and please excuse any perceived rudeness, Princess, but we're going to need to have words about the events at the Crystal Empire."

"What words?"

"We've been offering relief to the Empire for over a month now. I, and I'm sure others will agree, full heartedly support taking kind actions for the simple sake of kindness, but we're heading in blind here. The Crystal Empire has been hit with what has only been described as 'a coup,' and as a reminder, this has all occurred less then a decade after the Empire reappeared from its unexplained disappearance nearly a thousand years ago."

The delegate looked to their sides to see others agreeing while the princess sat resolute.

"This is in addition to the Changeling Invasion that occurred at Princess Mi Amore Cadenza's coronation as ruler of the Crystal Empire. Now, said princess is rarely seen by her people and the Princess of the Sun has left us without warning. I want to reiterate, that the ponies have trust in you all, but I do not like letting what seems like a growing issue stew under our noses."

Luna narrowed her eyes before closing them entirely. She took a calming breath. "I will be convening with my sister before the Sun sets tomorrow and I'll be sure that we meet with her niece before next week's court. Until then, it is my promise to you that a full press conference will be held where all of our knowledge of the events that have taken place will be revealed."

After a moment of silence to confirm that that was the princess' final word, things moved on.

"Last on the agenda is relating to our Prince Dusk Sh-"

"No comment."

The delegate nearly crumbled the paper in their hooves as they screwed their eyes shut. "Please, Princess, our prince's disappearance coinciding with the events at the Crystal Empire has many of us worried about hi-"

The delegate doesn't notice their fellow ponies stepping away from them as a shadow loomed. A thud boomed as Luna landed in front of the pony. She craned her neck to eye level and stared directly into their soul and beyond.

"No. Comment." After a tense silence, Luna stood at attention, dismissed the court with a flap of her wing and stiffly left the room.

"I told you we should've scratch that off the agenda when the Night Princess showed up."

"Shut up, Scribble."

"Okay."

. . . . .

Everything mostly looked as it did when the castle was first brought into existence by the Tree of Harmony. Its purples were darkened and its blues dulled, but the structure and the crystalline tree it sat upon looked pristine otherwise. While walking through Ponyville, a part of Celestia hoped that her journey would never end.

However, she found herself in front of the Castle of Friendship far too soon.

The princess steeled herself and dropped her illusion. She flexed her wings and brought herself into the air around the castle. She could feel the magical signature as it wound its way throughout the castle's entirety to the point she couldn't pinpoint exactly were the true source lied.

It reminded Celestia too much of when her sister had succumb to darkness and became Nightmare Moon, of when the tainted signature filled every hall of their old home in Everfree. It was almost enough to cause the princess to pause and delay her actions even further, but instead she filled her lungs and let loose the Royal Canterlot Voice.

"Occupants of the Castle of Friendship -- one Spike the Dragon and The-One-Who-Called-Himself-Dusk-Shine -- make your presence known!"

"Hey, Princess, no need to yell. I- I'm right here."

Celestia dropped her gaze to the castle's main balcony, where the baby dragon in question was waving nervously before slowly moving to twiddle his fingers. She drifted down to hover in front of him.

"Spike, are you well?"

The dragon gave a little salute. "Yes, ma'am. A little stir-crazy, but nothing a nice camping trip can't solve."

Celestia felt a bout of warmth in her heart, but kept it in check. She couldn't be careless. With a glow of her horn, Spike glowed in kind.

"Wha- Princess?"

"It's a truth spell, Spike. I can't take any chances. Now, are you well?"

"Y-yes, Princess. I'm worried sick over my big bro, but I want to get out of here, but I would never leave him behind, but the gems here are all starting to taste the same, but he's going through something so much worst, but-"

"Spike." Celestia's voice was soft as picked him up with her magic and brought him towards her. It was a bit of a dangerous move, but she couldn't resist. She's avoided making contact with the castle at all in fear of traps or other dangers. It couldn't be discounted that the baby dragon wasn't part of some machination meant to lure her in, but Celestia would gladly risk her safety to reassure another. "You are exhausted, young drake."

"Yeah, I was up early today." Spike melted into the princess' embrace. "This reminds me of when Dusk would hold me, but softer."

Celestia giggled, but reminded herself of why she was here. "Spike, is there any reason I shouldn't set foot on the deck."

"No? Not that I can think of."

"What about inside? Any reason to be on guard?"

"I mean, other than the fireplace while it's lit, the laundry room on a bad day, the bathroom while I'm using it or the library while we're organizing it." Spike's face scrunched up. "Or my room, because my stuff is there, and while I trust you not to go snooping, I'd feel better if-"

"That'll do, Spike." The Princess of the Sun hovered over the patio. She placed a hoof on the flooring, then another until she was flat on the ground with the dragon on her back. She was probably being overly cautious, but if that monster had Dusk Shine's mind and a month to prepare, she wasn't going to trust any of the detection spells she'd already cast. She couldn't even take Spike at his word under the truth spell since the stallion had a whole month to orchestrate his memories.

Celestia entered the Castle of Friendship. She sent out repeated detection spells that pulsed around every corner. The signature had reached maddening degrees. It felt like the same individual was everything, everywhere, all at once. She despised how much she'd allowed herself to rely so heavily on sensing the magic of others. It only served to make her blind.

As the pair entered the main hall, the princess spoke quietly. "Where is he?"

Spike was confused, but answered in the same low tone. "Dusk was in his room last I checked. He didn't take any pain dampeners yesterday, so I'm sure he's sore and hasn't gotten up yet." His eyes widened. "Ohsh, I haven't finished breakfast yet!"

The dragon slid off Celestia's back and scampered off towards the kitchen. The princess' first instinct was to stop the young one in his tracks, but she was already in the middle of channelling another detection spell for her to redirect her magic. She went to physically snatch him with her wings, yet froze in her tracks.

Celestia's detection spell had gone off and had finally successfully found somepony. It was useless though as the magical signature that had been overwhelming her senses had now focused itself into one point. The princess slowly arched her head to the top of the grand staircase. Standing there, shrouded in darkness, was a silhouette that made her teeth clench.

"Sombra."