The moment she'd stepped off the arriving train, she'd been running. Under normal circumstances, Twilight would be making more of a casual pace towards the palace of the Crystal Empire during one of these visits. But today, this was no mere vacation or visit to her brother. For something had occurred which required her full attention. It had been less than a day since she received the letter from her brother, informing her of what had happened, but even so, she could not believe it.

Sunset Shimmer had returned to Equestria.

There were so many questions that were plaguing her mind when she discovered that. Why was she here? How could she have come back through? Was this another attempt to seize power in some way? These an many others were buzzing about in her skull. It occupied her every waking thought, so much so that she did not even slow down to return the many greetings that the passers by in the street were giving to their nation's latest Princess. But Twilight felt nothing but concern right now. Sunset had once been a great adversary to her, and though she'd left her in the human world with the feeling that perhaps she could better herself, her return here cast serious doubt on that.

But regardless, she had to keep her attention on just getting there, and with the gates of the crystal palace in sight, she knew it was only a matter of time before these questions were answered. The guards at the gates saw her approach at speed and quickly used their magic to open the doors for her. Once inside, Twilight made straight for the lower levels of the palace, where Sombra's old dungeons were placed. Those old rooms had not been used ever since he was driven out, and even though they'd since been renovated to far more fitting accommodation, not once had they ever been used for the purposes of putting ponies in them. But, according to her brother's letter, that's where Sunset was being kept.

She did not like these lower levels, as they reminded her all too much of her first visit to the Empire a couple of years ago. Cold and still in an unused state, they were an unpleasant place for anypony. However, it did not take long for her to reach her place, as she saw Shining standing vigil outside one of the chambers. As she approached, Shining broke into a smile, albeit a small one, and Twilight did the same. When the two were within just a few feet of one another, Shining raised a hoof and placed it on his sister's shoulder affectionately.

But, as pleasant as this moment was, Twilight's attention was then drawn to the one standing guard by the door. Her smile grew even more as she saw that it was none other than her mate, Flash. The young pegasus couldn't help but return the smile to Twilight once he saw her, but it was rather brief as he returned to his previous stance, ever ready to assume his guard duties. Twilight would have loved nothing more than to catch up with Flash and her brother, but she knew that more important things were at stake right now.

So, with her expression now more serious, she looked up at her brother once more.

"She's in there?"

Shining nodded silently at that before turning his gaze upon the door, as did Twilight.

"Yeah. We don't know anything else about all this, but I figured you'd want to speak to her."

Twilight nodded back at her brother before returning her attention to the door. With that settled, Shining began to walk off, giving his sister one final glance before continuing back down the halls. No doubt he was off to make further arrangements regarding their new arrival, but whatever the reason, Twilight took a deep breath before moving forward, glancing one last time at Flash before raising her hoof and turning the knob of the chamber door. It creaked open loudly and the young alicorn stepped inside. Her eyes widened with shock when she saw that it was true. Her one-time enemy, Sunset Shimmer, was there, standing near the far wall of the relatively small room.

The moment Twilight entered, Sunset looked at her, with a mixed expression. At first it seemed like it might have been disdain, as one would expect when looking upon the one that had once defeated her. But, that soon changed to a look of resignation, as the unicorn let out a sigh. If she was here to start a fight, she wasn't showing it. However, as Twilight stepped inside, she caught sight of another pony standing near Sunset, and the moment she saw him she had to fight the urge to have her eyeballs pop out of her head in sheer shock.

It couldn't be, she told herself, but her eyes did not lie. For there, standing before her, was Flash. She stared at him for a few moments, as he did to her, and once she broke herself out of her daze, she immediately backed up out of the chamber, looking to see her Flash still standing outside. Her Flash, who unlike the one in the chamber was clad in the armour of the guard, turned to see Twilight's confused expression. He knew just from looking at her what she'd seen in there and let out a deep exhale, nodding to her, a sign that he knew what was going on in her mind and that this was no illusion before her.

That did not help things however, as it soon dawned on her exactly who it was that stood in the chamber with Sunset. For this was none other than Flash Sentry's human counterpart, no doubt transformed by the power of the magic mirror, much like she and Sunset had been made into humans when they passed through it. But even with that point being as easy as it was to figure out, it still left a very important question. Why was he here, and with Sunset of all people?

This silence from Twilight had lasted for quite some time, and Sunset had been patiently waiting for her to speak the first words. However, as time passed and Twilight just stood there with a dumbfounded look on her face, her patience wore thin, and she stepped forward and spoke in her usual commanding tone.

"Yes, it's me. Yes, this is the Flash from the human world. And yes, we both came here via the mirror."

Her old rival's word's did a good job of getting Twilight out of her self-imposed daze and the young Princess cleared her throat, out of sheer embarrassment if nothing else, before speaking.

"Yes, well...um. I must say...I wasn't expecting to see you again."

Her eyes darted from Sunset to the formerly-human Flash.

"Either of you."

Sunset gave a rather annoyed look at Twilight before replying.

"Believe me, when we last met I wasn't planning on coming back either. But...things change."

Twilight looked at her as she said that, as her eyes turned away from the young alicorn, as though trying to hide something. She then noticed the other Flash walk towards her and placed a hoof on her shoulder, gaining Sunset's attention. The two looked at each other for a few moments and, to Twilight's surprise, Sunset cracked a small smile. They way the two were looking at each other was very familiar, as it was often the way that she would look at her own Flash. But, she shook herself out of that thought as Sunset stepped forward.

"Truth is...I've missed this place. I may have lived in the human world for a few years now, but Equestria is my home. The thought of never coming back here was...too much. So, one day, I put my hand against the statue by the High School, out of foolish hope that something would happen."

Sunset then let out a small chuckle.

"Imagine my surprise when my hand actually passed through it."

Twilight nodded at that. it would have certainly been a surprise to her had their positions been reversed. Such a thing was not even supposed to be possible. And that thought led to Twilight's next question.

"But how? It hasn't been that long since I left, and the portal should still be closed."

Sunset nodded.

"That was what I thought too. But then I realised something. You and I weren't the only things to pass through that mirror."

Twilight tilted her head in confusion over that, not quite sure what Sunset was saying. But the latter merely stared at her in silence, waiting for her to figure out her meaning. It did not take long however, and soon Twilight's eyes were wide with surprise.

"You don't mean...the element of magic?"

Sunset nodded at that, and Twilight's mouth was agape. She did not know exactly how, but the element must have affected the magic of the portal somehow. That thing was created to allow the passage of people between worlds. Those who made it in ages past probably never considered having a powerful magical artifact travel through it also. And the element of magic was one of the most powerful there were. It then dawned on Twilight that the element may well have made the portal open permanently now, allowing free travel whenever the need demanded it. The possibilities of this revelation were mind-boggling to say the least. To have the worlds of ponies and humans open to each other forever? It could change everything.

For a brief moment, Twilight lamented the fact that the element was no longer in her possession. Had she and her friends not been required to return those artifacts to the Tree of Harmony a few months ago, she would have wanted very much to test just what kind of effect the element truly had on that mirror. Looking up at Sunset once more, it was clear from her expression that she too knew just how momentous an occurrence like this was. But even so, Sunset carried on.

"Once I realized that I could go home, I knew I had to. There a few...loose ends back here I needed to take care of."

Twilight wondered for a moment what those loose ends might possibly be, but her gaze then fell to the other Flash who spoke for the first time in this entire exchange.

"Sunset told me about this a few days ago, and I said I'd go with her."

Twilight raised an eyebrow at that.

"Why? The last time we met you two weren't exactly on the best of terms."

Through the corner of her eye, Twilight could see Sunset give a somewhat annoyed look at her, but even so her attention remained on the other Flash, who was responding to Twilight's words with a nod.

"True. But, like she said...things change."

Once he'd said that, the other Flash turned to look at Sunset, who smiled back at him. Looking at the two of them, at the way they were behaving around each other, Twilight could only describe such gazes as affectionate. It then dawned on her that some time had passed since she last saw these two, and though things might not have been the best between them last time, the situation may well have changed. Perhaps the two had grown close for a second time? She knew that it was a very personal thing, but even so, she knew she had to ask.

"So...are you two...you know...?"

The two looked at her for a moment before glancing at each other for a second time. After that they turned back to her, both wearing big smiles on their faces, Flash breaking the silence.

"It took a while, but yeah...we are."

To say that Twilight was shocked would have been an understatement. After all, it was hard for her to grasp that Sunset could have changed so much that Flash was willing to be with her again for a second time. But, even though she'd only known him for a brief time, Twilight knew that Flash was not fool enough to want to be with her if she was still the same as she was when they first met. But, even putting that aside, there was her own involvement with him to consider.

All three of them knew that Twilight and Flash had grown close during her time in he human world, and it was that closeness that had led to her approaching her world's Flash in the first place. And even though she'd been able to separate her feelings for the human and pony Flash's, it would have been a lie for her to say that there wasn't some small part of her that felt somewhat down for having learned of this. Even so, she'd moved past her feeling for him, however brief they may have been, a long time ago. So, looking at the two ponies before her, she too broke into a smile.

"I'm happy for you. Both of you."

The two smiled back even more, casting each other a loving glance before turning their attention back to Twilight. It staggered her to think that so much in that world might have changed in her absence. And that thought led to another, one that she was more than willing to voice.

"But why did you ask Flash to join you instead of somepony else? One of the girls for instance?"

Sunset looked away from Twilight, her expression a little uncomfortable.

"I though about it at first. After all, I knew they'd want to see you again. But...things between us haven't been perfect. They've accepted me, to an extent, but I did a lot to them. It's going to take more time than this."

Twilight's ears drooped a little upon hearing that. She was rather disappointed to hear that she wasn't going to see her friends form that world anytime soon. But, her attention was drawn to Sunset once more as the latter spoke up.

"Besides, I didn't want to bother them right now. They've got a lot of rock practice at the moment."

Twilight raised an eyebrow at that.

"Er...rock?"

Sunset shook her head, chuckling a little.

"It's a long story."

Twilight was tempted to ask further about that, but decided against it. But still, her fears from earlier were beginning to fade. When she'd first heard about Sunset's return, she feared yet another plot of hers to gain power in some way. Now though, she could see that this was not the case, and could let out a sigh of relief over it. And even though seeing her with Flash was unexpected, and at first a little disheartening, Twilight was willing to accept her old rival's return to Equestria.

The young alicorn looked on as Sunset began to step forward, opening her mouth as though she were about to speak. But, to Twilight's confusion, she stopped before a single word left her mouth, and she looked right past Twilight. The young Princess did not know why, but for some reason all the colour in Sunset's face began to drain away, as though she'd just seen a ghost. It was here that Twilight began to hear the sound of approaching hoofsteps from behind, and turned to see who it was.

Her expression became one of great surprise as she saw that there, standing with a look of utter seriousness upon her face, was Twilight's beloved mentor, Princess Celestia herself. The elder alicorn was not looking at Twilight however, but at Sunset, and her tone of voice matched her serious expression as she spoke.

"It's been a long time...my student."