The light faded, and Cold Reason slowly floated back downward towards the circle of her rainbow-powered friends. For several silent moments they looked at her expectantly, her pale form hovering mere inches above the rock. Her eyes opened when her hooves touched the ground, and she looked around at all the others – the six around her, and the seven watching from nearby.

“Thank you,” she told them, bowing her head slightly as a soft and genuine smile graced her lips. “I know now what must be done, and you have given me the strength to do so.” Those words seemed to erode the remaining tension in the air around them, bringing smiles to her friends even as their power faded and they touched down upon bare stone.

Cold's smile faded into a solemn look as she turned around to face the valley, her gaze soon finding her grief-maddened other self as she launched a salvo of magical bolts that arced around and struck all over her own body. Cold closed her eyes and shook her head, then with the barest of effort launched herself into the air. She streaked through the sky like a shooting star, and flew all the way to her rampaging other half.

The Oathbreaker stopped mid-charge and looked straight at her, ears alert and eyes wide. And as Cold stopped directly in front of her, she took in a breath and bellowed. It lasted for minutes before her massive lungs finally ran out of air, but all through it Cold simply floated in place and weathered the wind and sound without changing her expression – her muzzle blank, but her eyes filled with sadness and regret.

“No,” Cold said, her voice as calm and steady but not devoid of emotion as it had once been. “I need to stop this.”

“I CAN'T!” the Oathbreaker wailed louder than thunder, folding her wings and dropping from the sky like a stone. She plummeted head-first to the barren land below, Cold flying down alongside her and disappearing into the cloud of dust she kicked up on crash-landing. The cloud dissipated in an instant, though, revealing the Oathbreaker lying on the stone and thorns with her head buried in her legs and wings. “WON'T END! EVERYTHING DEAD! ME! MY FAULT! WANT END! 'M SORRY!”

As she wailed and sobbed, Cold flew in through her limbs and hair and landed on the top of her muzzle. “I have to stop this,” she repeated, her voice still calm but more forceful than it had been. “This isn't helping.”

“CAN'T! NOTHING! WORTHLESS! ALL DEAD! MY FAULT! ALWAYS! JUST LIKE!”

“No. I cannot let myself do this. They do not want this. This is not justice.”

“THEN WHAT IS? DIE! END! MY FAULT! ALL MY FAULT! I SHOULD-”

“NO. I have to keep living. I cannot give up on life. They do not want this. It is not justice.”

The Oathbreaker wailed, and Cold closed her eyes and laid her head against her glowing head. “I have to keep living. I cannot give up on life. They do not want this. It is not justice.” And in her mind a door was flung open, and she flung herself at herself, and inside and out Oathmaker was consumed by light...

Those watching from the mountainside were forced to avert their gaze from the blinding flash that swept across the valley. It seemed to linger around them, dispelling the gloom they'd felt in the air since arriving and replacing it with a curious stillness. And then, at a pace that felt far slower than it could truly be, the light faded and the darkness of night took over.

The ponies blinked and Discord took his eyes out and rubbed them on his chest, and the group looked around as if seeing the valley for the first time.

“...the clouds are gone,” Applejack said softly, looking up at the shining moon and the star-filled sky that surrounded it.

“What happened?” Starlight asked, stepping closer to the edge of the cliff and staring at the large sphere of white light that was now sitting where Cold and the Oathbreaker had been.

“Oh, I hope it's something good,” Fluttershy worried. “I don't think I can take anything else bad happening to her...”

“I'm sure we'll find out soon enough, Fluttershy,” Twilight told her, gaze fixed on the sphere of light.

She heard a hoofstep behind her, and looked back to see Princess Celestia standing over her looking out at the light as well. “Yes,” she said softly, distractedly, her eyes squinting as though peering through the bright light. “I believe we will...”

And without another word she spread her wings and took off, her sister just behind her. Following their lead the others left the ledge by wing or by hoof, all headed towards the sphere of light. Only Discord remained behind, crossing his arms and snorting in annoyance.

Soon enough the twelve regrouped at the base of the sphere of light, which sat like an impossibly large egg partly buried in the ground. And, to their surprise, it was growing smaller – every second it seemed to pulse, expanding briefly only to retract further inward a moment later. The pulses came faster and faster and greater and greater, and then...it popped.

“Wow, that was a balloon the whole time?!” Pinkie said, eyes wide with amazement. The others ignored her, too fixated on the body of Cold Reason floating in the center of where the sphere had been.

She hung in the air for less than a second, then dropped like a stone.

A collective gasp, and the six and the two elder Princesses raced forward out of fear and concern – and for the second time, Rainbow and Twilight caught her before she got hurt. And as they gently lowered Cold to the ground, it struck several of the group how much different she seemed to look – fuller, more solid, more real. Her coat a warmer white; her mane a more vibrant black; her every breath more full of life. Gone was the trio of dots from her flank, replaced by a much more complex mark – the outline of a shield around the outline of two forelegs hooked together at the elbow.

She began to murmur and open her eyes, which only caused her friends to crowd around her even more. “Hey! Hey, are you alright?” Twilight asked.

“No, Twilight Sparkle, I am not.” Even her voice had changed, however slightly – still light and clear and almost monotone, but with a new-found sharpness about it as well.

“Oh no,” Fluttershy said, pushing past the others to get a better view of her, “nothing's broken is it? Where does it hurt? How are you feeling?”

Cold, trying to lift herself up on her forelegs, looked at Fluttershy with deep gray eyes and blinked. “No. My entire body aches but not to a particularly serious degree. And...,” she paused and looked down at her own hooves before answering the third question, “many things, it seems. Interesting.”

“Oh my,” Fluttershy replied, stepping back briefly with a frown on her face that the others shared. “I hope you're feeling better, at least.”

“Yes. I am, thank you,” Cold answered, still looking down at her hooves with an odd expression, as though she wasn't entirely certain what they were.

Several of her friends let out sighs of relief. “Well it's good to hear that that's all better then,” Applejack said. “I was afraid that even after all that, you'd still be beatin' yourself up over what happened all those thousands 'a years ago!”

Cold looked at her, gaze as blank as it had ever been. “You misunderstand, Applejack. My grief and guilt have not gone away. I am simply...,” she paused and briefly looked down before looking back up with sadness in her eyes, “no longer consumed by them to the extent that I was.”

Renewed concern swept over her friends. “But...even after all that, you're still...?” Twilight asked.

Cold nodded. “Yes. Your friendship has given me the strength I needed to continue moving forward, and I thank you all for it, but my pain can not be eased so quickly.”

Another silent moment passed before somepony spoke up again. “So...what now?” Rainbow asked. “Cause I gotta say, I wasn't expecting...,” she waved a hoof vaguely at Cold, “this to happen.”

“What were you expectin'?” Applejack questioned. Rainbow just stared cluelessly at her for a moment before shrugging. Applejack's face fell into mild annoyance.

Expectant looks fell back on Cold, who closed her eyes and shook her head. “I do not blame you for not expecting this. I barely understand what I've done myself, though,” she added with a distinct touch of bitterness in her voice, “that has often been the case for me. But...,” she looked back up at her friends, “I do know that this is the best path for me to go down. I have succeeded in sealing myself away as I had wanted since the beginning, though instead of stone the seal is...,” she looked down and put a hoof to her chest, “my self.”

“Your...self?” Rainbow asked, brow raised in disbelief.

Cold nodded again, keeping the hoof on her chest. “Yes. My body...my power...and much of my mind...all that made up the Oathbreaker has been sealed within this new body so that it might rest, and perhaps one day heal. So until that day arrives, I will live my life as Cold Reason.”

Behind the others Celestia and Luna shared a surprised look. “You...will not even take back your name, elder?” Luna asked.

“No,” Cold answered with another shake of her head. “I...am not ready yet. The shell named 'Cold Reason' will help me reconnect with the world in ways I do not believe I could do as Oathmaker.”

“And what of your magic?” Celestia asked, her expression betraying that she already suspected the answer.

“Under control,” Cold answered without hesitation. “I am certain of it. I used the excess that had...afflicted me...to recreate this body and fuel its seal. And I should be able to call upon my original form and magic at any time,” she suddenly looked away in shame, “though I fear doing so will not be wise for a great while...”

Celestia nodded. “I understand. Still, I must say that it's a joy to have you back, old friend, no matter what form you take,” she told Cold with a smile as warm as the midday sun.

“Agreed,” Luna added with a smile of her own. “There will be much rejoicing and merry-making!”

“Woo!” Pinkie cheered, leaping up and waving her hooves in excitement. “Get ready for the greatest 'Welcome Back!' party ever!”

That was enough to earn a short, small laugh from Cold. “Yes,” she said, “I suppose I'll join your celebration after all.”

Spirits lifted as the group went to rejoin Spike, Starlight, Cadance, and Shining Armor at the rim of the crater, the ponies expressing their joy at the well-earned and relatively happy ending and how much they were looking forward to getting to know – or reconnecting with – Cold Reason.

But before they reached the others, Twilight caught Cold's eye and hung back. “Sorry for asking this,” she said to Cold's questioning look, “I don't want to spoil your mood or anything but at the same time it's kind of bothering me, and I'd rather have it answered sooner rather than later...”

“What is your question, Twilight Sparkle?” Cold asked when Twilight trailed off awkwardly.

“It's about what you said before,” the Princess explained. “About having to...,” she waved her hoof vaguely before pointing it at Cold's chest, “recreate your body. What did you mean by that?”

Cold blinked. “The original form I took as Cold Reason was consumed when I reunited with my...other part. It was unexpected, but in hindsight I should have foreseen it. But, as with so much-”

Twilight cut her off with a smile and a hoof on her muzzle. “Don't worry about it. What you did, the magic you used, was something I've never seen before. I don't think anypony has. It's only natural that you didn't know everything about it. But you should still be proud that you were able to do it! If you hadn't, then, well...”

As she trailed off uncomfortably, Cold blinked and looked ahead to the rest of her friends. “I understand. Thank you, Twilight Sparkle.”

“No problem!” Twilight said, and the two quickly caught up with the others.

And there, at the edge of the crater surrounded by all of her new friends, Cold Reason bowed her head and smiled. “Friends,” she said, “I cannot express how much I owe to you all. For thousands of years I have been trapped in my own grief and despair, and at the thought of myself causing even more death and destruction my only wish was to trap myself further. But because of all of you,” she looked up and across their encouraging smiles, “all of your hard work, all of the risks you took to fix my mistakes, all of the friendship you showed to a stranger, I have been saved from myself. I have been given another chance at redemption, at justice, and at life; and this is a debt that I swear this day to repay you all in full.”

To the surprise of even the two eldest Princess, as she spoke a faint yellow magic swirled up around her, lifting Cold into the air even as she deepened her bow towards Twilight Sparkle. For a split second the image of a large and wild-looking alicorn, brown in coat and green in mane, overlaid her; but it was gone in an instant and eleven threads of glimmering golden magic shot out from Cold's heart and connected to the heart of each pony around her. A moment later a twelfth thread appeared, colored silver, and connected to Spike. And lastly, at a slow and extremely begrudging pace, a dull copper-colored thread extended away from the group and up towards the mountains...

And then it was over, the magic dispersed and Cold falling gently back down onto her hooves. The others gaped at her.

“Uh, what was that?” Rainbow asked.

Cold looked at her and blinked. “That was me making the oath I swore to repay all of you formal. I am aware of the risks posed by tapping into my true power right now, but...,” she looked down briefly, “I believe it best to try to resume the things that were once so normal for me, no matter how difficult they might now be.”

“Whoa, hold on there,” Applejack said, pushing her way forward. “I get that you're grateful and all, and that oaths are mighty important to ya, but that magic you just didn't ain't set in stone is it? 'Cause the last thing I want is somepony goin' around and bendin' over backwards tryin' to repay somethin' that I don't even consider a debt. 'Specially somepony that's bein', I don't know, magically compelled to do so.”

Another look, and another blink. And another for good measure as Cold finished coming up with an answer. “I believe you are mistaken, Applejack. I am no more compelled to fulfill my oaths than you are to fulfill your special talent. The spell I cast simply helps me keep track of them.”

“Wait, all that was just some...some kind of magical checklist?” Twilight asked in shock.

“Seems a bit dramatic if you ask me,” Spike chimed in, feeling the spot where the silver thread had touched him.

Cold looked at him and shrugged. “It is as dramatic as I like it to be. Though not, I suppose, as dramatic as it once was.”

“What, did you give even more of a speech during it?” Spike scoffed.

“Yes,” Cold answered without hesitation. “I have also tried adding magical sounds to the ritual, but I was never able to decide on a final score.”

Spike looked at her, dumbfounded, and blinked. “Oh. Well okay then.”

“No, not okay then,” Applejack spoke up yet again. “Cold, it's all fine and dandy if'n you aren't gonna force this with magic, but that doesn't change the fact that I don't want you runnin' around tryin' to do every little thing for me, or anypony else, as a way to pay us back!”

“You are mistaken again, Applejack. Small favors, no matter how many, do not repay a large debt,” Cold explained. She paused a moment, then looked out at all the others once more. “What I have sworn to each of you is to aide you in a moment of need as you have aided me. I do not yet know what tasks I will have to perform to repay you all, only that they will be equal to the part you played this night, and that I will know when each debt is repaid. And they will be repaid.”

It was a few moments before anypony spoke again. “Well then,” Celestia said, the corners of her mouth turned up in amusement. “I believe that settles that matter, right Applejack?”

Applejack looked at the Princess, then back at Cold. “Uhh...I guess so,” she said reluctantly, not quite meeting Cold's gaze as she kicked at the ground with her hoof. “I still don't like it, though...” she added under her breath.

“Noted,” Cold told her to Applejack's surprise. “Now then. May I ask that we leave? I am...,” she looked down sadly, “not comfortable staying here longer than I need to.”

“Of course!” Twilight said with a bright smile. “I'm sure we could all use some rest right now.”

“And a party!” Pinkie added, jumping up and blowing a party horn.

“That too,” Twilight told her she and the others laughed. “But let's wait until we're back in Canterlot.”

“So we're finally leaving this dreary dump then?” came the voice of Discord, who stuck his head out of the ground without warning and looked around at the group, Cold's expression immediately falling into level distaste.

“Yup,” Fluttershy answered him as he pulled himself out of the ground with a slight popping sound. “And we'd all really appreciate your help in getting back home.”

Discord crossed his arms and snorted. “You'd better, after how long you've kept me waiting.”

He raised an arm, snapped a claw, and the group was gone.

The fourteen arrived in the same place they had left hours before, the palace dining hall. They were greeted first by a few rather startled members of the cleaning staff, then a pair of palace guards, and eventually by Celestia's personal assistant, the mayor of Canterlot, and several other high-ranking diplomats and members of the Equestrian government. It was quickly explained that they'd been in an emergency meeting, called on account of the letter Spike had sent off after the first wave of attacks against the Oathbreaker had failed. For the first time since Tirek's attack, and thus the second time in centuries, old laws and protocols for a (presumed temporary) transfer of power had been brought back out, and preparations were being made to both reinstitute the full Equestrian military, as well as inform the other nations of the world of the threat they needed to be aware of.

Needless to say, the officials were all relieved that they wouldn't have to actually go through with any of it. Though, they eagerly informed the Princesses, they would have handled the situation perfectly if they'd had to. Celestia agreed wholeheartedly.

With lightened hearts the members of the government returned to business as usual, which for most of them meant a return to the warmth of their beds. Most of Equestria's Heroes followed suit, tending their wounds and retiring to the rooms they'd been assigned days ago. Even Princess Luna decided to suspend her nightly duties for an hour so she could rest.

And all too soon the morning came, Celestia raising the sun and the others raising themselves hours later. They took a jovial, if late, breakfast, and soon after broke apart for the new day's plans – Twilight, her family, and her assistants taking Cold to the Royal Library and Archives to try to catch her up on all that she'd missed during her self-imposed imprisonment; Pinkie and Rarity leading the rest of their friends (and several members of the palace staff) through the city to plan a throw-together party for that afternoon, with Discord spending most of the time either making trouble or pestering Fluttershy about whether or not she'd been impressed by his valor and power in the previous night's battle; and Celestia resuming the mantle of governance she'd held for so long.

Even the party itself was over all too soon, a large yet surprisingly modest and quiet affair – at the guest of honor's behest – held only for those who knew Cold's secret. Of course, Pinkie had loudly, enthusiastically, and repeatedly informed the others that it was only the first party she was going to hold for 'Coldie', with several more already being planned for their return to Ponyville.

It was after one such declaration that the question of Cold's living arrangements was brought up, with Cold herself promptly explaining that she would prefer to live close to as many of those that she needed to repay as possible – which meant Ponyville. Each of the Element Bearers volunteered to house her, but after Spike pointed out that most of them didn't actually have the room to board another adult pony (or in Rainbow Dash's case had a home that would be difficult for Cold to access), it was decided that Cold would stay in the rather spacious Castle of Friendship for the time being.

And thus, a few hours after sunset and moonrise, the party wound down and the guests began their journeys home.

“And that covers the bedrooms, the bathrooms, the kitchen, the library, the Cutie Map, and just about every other major room in the castle,” Twilight explained as she and her friends led Cold Reason on a tour of the place she'd agreed to stay at. Despite the late hour the full group had gone straight to the castle after having gotten off the train, the five non-residents citing a desire to help their newest friend get settled in as best they could.

“Yeah,” Spike said as the group walked down one of the many crystalline hallways together. “All that's really left is the lab where Twilight and Starlight do their more...practical research,” he added with a smirk and waggle of his claws.

“C'mon, Spike, all research is practical!” Twilight replied.

“Oh really?” Spike countered. “Even the research into historical organization methods?”

“Especially that!”

Cold raised a brow as the others giggled and laughed, and Starlight caught her eye. “What he means is that it's where we do the research that can't be done just with books,” she explained. “But it's mostly just equipment in there, there's not really any point in showing it off right now.”

“Oh, that's not true at all!” Twilight said with a happy smile, trotting back to the front of the group. “Even if there's not a lot to show off, Cold should still at least see it. Right?” she asked the mare in question.

Cold gave a noncommittal shrug. “I see no reason to put off seeing it.”

Twilight squealed in excitement and clapped her hooves together. “Great! Perfect! It's right this way!” she said with a wide grin, grabbing Cold and galloping off.

And soon enough, the whole group had reached the spacious room that Twilight had converted into a laboratory. As Starlight had said, it mostly held tables and shelves containing the equipment needed to measure or test various things, but set up on the far side of the room was a large mirror set in an elaborate crystalline frame shaped like an upside-down horseshoe. More horseshoes ringed the mirror's stand, and fixed to the ornamentation at the top of the mirror was yet another horseshoe shape with a piece of stained glass depicting a single rearing earth pony. The entire thing was hooked up to a bizarre contraption of wood and brass and rubber tubes and wires and various metal bits that didn't appear to be doing anything at the moment.

Cold stared at it inquisitively, walking up to it with Twilight. “Cool, right?” the Princess asked.

“Interesting...” Cold replied, her expression level as she examined the reflection of her manufactured body.

“It may look like just a mirror,” said with her eyes closed and more than a hint of pride, “but it's actually a portal to a completely different dimension!”

Immediately Cold's attention snapped her way. “...excuse me? I do not understand what you mean,” she said with a puzzled look.

“Heehee,” Twilight giggled. “I'm not surprised. I doubt even somepony as old as you has ever seen anything like it! Through this magic mirror,” she explained, looking into the mirror alongside Cold, “is a whole other world, parallel to ours but populated by humans instead of ponies.” When she got nothing in reply but a look of shock, Twilight smiled. “I know it's hard to believe, but trust me – I've had some amazing adventures with my friends in that world.”

“Uhh, Twilight?” asked Spike, nervousness rising in his voice. “Did you, uhh, heheh, you didn't leave the portal on, did you?” The room's attention quickly drew first to Spike, and then to where he was pointing – the book sitting on a small shelf at the very top of the apparatus the mirror was hooked up to. It was a thick brown journal bearing Princess Celestia' cutie mark on the cover, but more importantly it was glowing red and vibrating.

Twilight's brow furrowed. “No, I didn't. Starlight?” she asked her student.

“I didn't touch it,” Starlight answered with a quick shake of her head.

“Then who did?” Twilight asked, worry seeping in to every inch of her expression.

“Maybe it's related to the messages in the book,” Spike suggested, looking up again at the journal. “Maybe something happened?”

“Maybe you're right...,” Twilight said, reaching out with her magic to grab the book...only for magic to suddenly surge through it, down the wires and into the coils of the apparatus which sent out sparks of magic that collided and formed in the air between them a miniature maelstrom, which immediately surged into the mirror...

...and then a pony tumbled backwards out of it. Those who'd been standing nearby let out startled gasps and backed away, giving Twilight and Spike the room they needed to rush over.

Their mouths gaped when they saw the familiar-looking pony lying on the floor, dazed and confused and on her back. Between the amber coat, the vibrant red mane streaked with yellow, and the horn jutting out of her forehead, Twilight Sparkle came to a quick conclusion.

“Sunset Shimmer?!”

Author's Notes:

And thus, dear readers, we come to the end of this story - and the beginning of another. And also the end of another too? Yeah, keep that stinger in mind for when Synchrony debuts later this summer.

Either way, thank you all for suffering through staying with this story to the end. I get the feeling that it's...odd, and awkward, and unpolished, and alicorn OCs aren't generally liked by the fandom, but... Well, I enjoyed writing it, and I like Cold Reason/Oathmaker as characters even if I haven't quite gotten a hang of their voices yet. It's also opened up several doors in terms of potential future stories, mostly fleshing out the lore of the world of Equestria as it exists in my mind. And secondarily having what amounts to a genie in a (living) bottle around to (rarely) solve problems. Mostly non-canon problems, of course, as I'd rather not mess with canon character growth unless it either proves redundant or there's an opportunity I can't pass up.

And don't worry, any future stories featuring Coldie/Oathmaker will have additional...trouble...to compensate for having such a powerful pony around.

Let's see...one last thing I want to mention is not to expect any in-story explanations anytime soon for why the portal was active. Originally I had wanted it to be active by its own rules, but after doing some calculations last night I realized that was impossible by my own (still-unspoken) rules for its cycle, thus leaving a plothole in need of filling. It would be unreasonable in my eyes to assume that Twilight, Starlight, or Spike would simply leave the thing active when it had no reason to be and they were going to be away for some number of days, meaning that somepony else would have had to open it.

I don't yet know who that somepony else is, so please don't expect an answer to it in Synchrony, but I do intend on explaining it at some point in the future. I'll explain my reasons for all this later tonight, so for now...just treat it like Cerberus abandoning his post as guard of Tartarus.

That's about all I'd like to say right now. Despite my pessimism I do hope this story was an enjoyable read, and I look forward to hearing any thoughts and reactions regarding both the finale and the story as a whole.

I'll see you all in a few hours when I post the final SYNCHRONY short, 'You Wouldn't Understand'.

- Fangren