He looked out upon the streets of the crystal city, the wind gently blowing through his window. Shining Armour, prince of this Empire, was in his office, having just finished much of his daily paperwork, and was thus taking a short break to admire the scenery. One of the perks of this job was getting quite a view from his office, as it gave him a magnificent look over the shining crystal buildings of this city. Despite his role as head of the Empire's military, it had been relatively quiet here, with only the Empire’s restoration having caused any major difficulties.

As he began to turn away from the window however, he glanced at somepony down in the street. He gave the window his full attention once more as he saw that there, walking in the streets, was his younger sister, Twilight. She was out amongst the other ponies, whom had all become used to not bowing as they would do with other princesses, owing largely to Twilight's general discomfort with such behaviour. But what caught Shining's attention more was that she was not alone, and seeing the one she was walking with caused him to narrow his eyes somewhat.

"Sentry". He grumbled

Flash Sentry. The stallion had his back to him and was clad in the usual golden armour of the guard, but there was no mistaking him. There was no other guard that Twilight would ask to accompany her down the street like this. Despite Shining's protests, Flash had been chosen by Twilight to act as her personal escort while she was here. Shining knew fully-well that Twilight didn't really need an escort while she was here, and that her real reasons were for her to be closer to her colt-friend. On the one hoof, it brought a smile to Shining's face to see Twilight become more comfortable with exercising her authority. On the other, having it to be used to do this sort of thing irked his "protective big brother" instincts.

He knew he wasn't being fair to Flash by thinking that way. The guy was, after all, a stallion of decent character, and had been a solid and dependable guard during his relatively brief time here in the Empire. And from what he'd heard, he and Twilight were really happy together, which was something Shining could never be angry about. If he was, in some way, making his sister happy, then that was something that Shining couldn’t begrudge him about. And so, sighing heavily, he turned and began to sit down to resume some of his work.

But, as the minutes rolled by, his mind began to drift towards Twilight and Flash once more. It was not so long ago, only a few months by Shining's count, that he'd first brought Flash here into his office, wanting to question him about his relationship to Twilight. Fortunately for Shining, Twilight had not been too angry about him doing that. However, Shining recalled all too well that Flash had said something to him that day which had piqued his interest. A thought which had buried itself into Shining's mind and never let go.

According to Flash, Twilight had approached him shortly after the attempted theft of her crown by Celestia's former student, Sunset Shimmer. Shining himself had not been here for that incident, but had learned all about it once he'd returned to the palace. Regardless, Flash had told him that Twilight first approached him after that incident and the two had hit it off rather well. But, during Shining's interview of him, Flash had said that there was an important reason why Twilight had gone to him specifically, rather than some other guard, but that it was a personal reason she wouldn't want others to know about.

That information had set off more than a few alarm bells in Shining's mind. The notion that there was some big secret behind his sister's relationship didn't sit well with him. What could she be hiding? What's worse is that it seemed to be only him who was being kept in the dark about this. When ever the issue of Flash had arisen in conversation, Twilight's friends had always given each other knowing looks, as though they were in on some secret that Shining was oblivious to. The white stallion knew that Twilight was close enough to her friends to know that, if there was some big secret, they might well have been in on it.

But why would she want such a secret kept from him? He was her brother, her own flesh and blood. Did she not trust him? No, Shining thought. Twilight DOES trust me. But even so, she was keeping something from him regarding Flash. Was she afraid of what he might do if he found out? If that was the case, then was there something he SHOULD be afraid of? Shining did his best to bury such thoughts. He had, after all, poked too far into his sister's personal life already with Flash. To go any further might make things worse between them. And after what happened between them prior to his wedding to Cadence, he was in no hurry to risk such a split between them anytime soon.

Still, as he looked out of the window, at the sight of Twilight and Flash, happy in each other's company, a thought arose in his mind once more.

"Twilight goes her whole life never showing an interest in stallions. Then she goes through the magic mirror, and after she returned she's suddenly going out of her way for this one guard."

The magic mirror. The doorway through which lay a whole other world. It was there that Twilight had gone to pursue Sunset Shimmer and retrieve her crown. That mirror was the key to this mystery, Shining knew it. He took a deep breath and gained a look of determination on his face. He knew that Twilight would be more than a little angry with him if she found out what he was doing, but the elder stallion had convinced himself by this point that he had little choice in the matter. And so, putting down his papers on his desk, he made his way out of his office.

He'd walked these elaborate halls many times before, having lived here for almost a year now. As he passed the entrances to many other rooms, the guards stationed there, pegasi, unicorn and earth pony alike, all saluted to him as he walked by. Ever the solider, Shining saluted them in return. But he couldn't allow himself to be distracted by such things. Not today. And soon enough, he found what he was looking for. The royal throne room. This massive chamber was quite a sight, forged from the same brilliant crystal as the rest of the palace, the light from it's many windows filled the room and caused them to glisten.

Shining took a brief moment to reflect on just how fortunate that he and his wife were to live in a place like this, affording himself a small smile as he did so. But that smile faded as his eyes darted to something near the throne itself. It was tall and etched with many strange symbols, it's reflective surface glistening like the crystal walls which surrounded it. It was the crystal mirror. Shining's eyes narrowed as he approached the magical object. He walked towards it before stopping just a foot away from it. Staring at the surface, Shining raised a hoof and placed it against the reflection. Not being the proper time, his hoof did not pass through it like a portal, but merely touched it, like an ordinary mirror.

"This is the source of it." He said to himself.

Twilight had passed through this mirror into a whole other place. A place in which he had no knowledge. As far as he knew, only two ponies had ever passed into that world. One was Sunset, and the other was his sister. With the time being wrong, he knew he could not simply walk through and get the answers he wanted, which was more than a little frustrating for him. Instead he hoped, perhaps in vain, that simply staring at the thing long enough might give him the insight he was looking for.

And, in a strange way, doing just that did indeed lead to something, for it was not long before Shining hear the sound of gentle hoof-steps approaching him from behind. Being in front of a mirror, Shining didn't need to look behind him to know who it was, as he merely glanced at the reflection. It was a young alicorn, pink in her mane and fur and bearing a tiara upon her head. Cadence, his beloved wife. Seeing her, her beauty, always brought a smile to Shining's face, but that smile faded a little once his wife began to speak.

"Shining, honey......what are you doing?"

Shining realised just how much trouble he would be in if Cadence knew the full extent of his presence here. She was, after all, the princess of love. So the very idea that he would in some way be interfering in the romance of another couple would be inherently upsetting to her, especially since she'd gone out of her way to support the idea of Twilight and Flash being together. So, thinking fast, Shining turned around and forced a smile.

"Well, dear, I was just thinking about what Twilight went through, going through this mirror. As you know, I wasn't here when Sunset tried stealing her crown, so I'm a little sketchy on the details."

One look at his wife's face, at her raised eyebrow and piercing eyes, made it clear that she wasn't buying a minute of this. The married couple stood there in silence for a while, Shining's eyes darting back and forth, before Cadence finally broke the silence.

"Prince Armour, you wouldn't, by any chance, be trying to learn something about Twilight would you? Perhaps something to do with her new beau?"

Shining tried his best poker face for a few seconds, contemplating outright denying her claims, but he knew that at this point such an action would be useless. Instead, he exhaled deeply, his ears now drooped in defeat as he nodded. Cadence shook her head, clearly a little disappointed in her husband's actions. She'd have probably hoped that he would have moved past this whole issue with Twilight and Flash by now. And in truth he had done to a great degree. He'd been quite accepting of it at this point. But that one nugget of information that was being kept from him was eating away at his mind, and was something that simply would not let him be.

Realising this, he decided that the best course of action was to be upfront about it.

"Alright. You caught me. This IS about Twilight and Flash. But it's not just me being over-protective. I think there might be some other reason why she decided to get together with the guy. A reason she doesn't want me to know."

Cadence's expression softened somewhat as she kept on listening to her husband, who was now turning around to look at the mirror once more.

"It all began with this. Twilight went through, got her crown, then, out of nowhere, wanted to get together with this specific guard pony."

He turned and looked at Cadence with a slight frown.

"Something happened to her in there, and I don't know what."

Cadence stared at him for a while before sighing. Despite her disapproval of his actions, she understood that it was, at the end of the day, out of love. Shining and Twilight had been very close throughout their lives together, closer perhaps than any other siblings she knew about. It was only natural that he'd be protective of her, especially if something had happened to her without his knowledge. After all, it was clearly a family trait, as Cadence had heard that Twilight was similarly dogged in her actions towards the disguised Queen Chrysalis prior to her and Shining's wedding. These two were always out for each other, so it would have been wrong for Cadence to just accept that he'd roll over and forget about something like this.

She approached her husband and gently placed her hoof upon his shoulder.

"I understand. But you have to realise that if Twilight's fine with all of this, so should you."

Shining looked away reluctantly before sighing.

"I know that. And I feel terrible that I'm going behind her back over this. But if I only understood what happened in there better, I might be able to get past this."

He looked upon the mirror once more.

"What do you know about the world beyond that mirror dear?" He asked

Cadence shook her head as she now stood alongside Shining, now looking at the mirror herself.

"No more than any other pony I'm afraid. Twilight said it was a world inhabited with strange creatures on two legs."

She glanced over at Shining before continuing.

"What did interest me though was that, according to Twilight, those in that other world were almost note-for-note duplicates of those here in our world."

Shining raised an eyebrow as he turned to face his wife.

"What do you mean?"

Cadence scratched her chin before answering.

"Well. All the people over there are in many ways the counterparts for the ponies in our world. Twilight met five such beings that were more-or-less exactly like her friends here, like Rainbow Dash, Fluttershy and all the rest. Even Celestia and Luna had doppelgangers over there. So for every pony in our world, there was one of these two-legged things over there who were exactly like them."

Shining turned away from Cadence and looked at the reflective surface of the mirror. What Cadence was telling him was, without question, fascinating. An entire world, filled with unknown creatures that perfectly mimicked the ponies of our world. He mused over the notion that he himself and Cadence might have such copies over there, or that there may indeed be another version of his sister out there in that world somewhere. Though he was certain that if such a person existed, Twilight would have surely told him about her.

But, as he dwelt on this notion a new thought occurred to him. It was only after Twilight had returned from this world that she began to show an interest in Flash, a pegasus she'd never met before. But then it hit him. What if she HAD met him before? Cadence had just told him that Twilight said every pony had a counterpart in that world, and whose personalities matched their exactly. If that was true, then that led Shining to the only reasonable conclusion he could reach, and it put this entire situation with Twilight's relationship in a whole new light for him.

"Did Twilight meet..........another Flash?"