With the horrible experience of the hospital behind her for the moment, Celestia's focus had once more returned to the Summer Sun Celebration and what had to be done.

She needed to prepare for 'her' return, and the horror of earlier had thrown quite a wrench into her plans. The Solar Princess was under no delusion that this strange and unsettling event was over, but neither would she allow it to get in the way of her long awaited meeting.

Still...

Day Court had ended early today in preparation for the festival, allowing Celestia time to make her own personal preparations in private. The sun would still rise and fall without Celestia's guidance but, as a lasting effect of Discord's reign, it was a chaotic affair.

If Celestia didn't regulate the rising and setting of the sun and moon, days could last anywhere from fifteen to thirty-six hours. As such, she had long ago devised a spell that would passively monitor and auto-correct the path and speed of the sun's trajectory.

She only took over personally during the early hours of dawn and the late hour of dusk. Once, long ago, she had shared this task with another, but had since grown used to doing it alone.

These were the thoughts Celestia ruminated on as she sat in front of her vanity. There were the thoughts she preoccupied herself with, as she tried not to think about what she'd witnessed earlier.

Still, those other thoughts resurfaced despite her efforts to push them away. Those mares, their horrible 'words', their eerie message and its ominous meaning. Like clockwork, the words and images came back again and again.

What happened to those mares?

Who or what did this to them?

Who was this 'Dead Goddess' they spoke of?

They couldn't have been talking about 'her', could they? That wouldn't have made any sense, it's not like she was dead. She was merely trapped—banished and bound to her lunar prison... for one thousand years.

A sentence that was soon to expire.

All these questions and more swirled around Celestia's head, pushing back thoughts of the festival and the inevitable arrival of the one she cherished the most—the one she had wronged so many years ago.

And if they weren't talking about her, then who or what where they talking about? Who was this Dead Goddess, what manner of creature was she to be involved in whatever happened with those mares?

As she observed her features in the mirror, Celestia flicked an ear worriedly. She didn't know what to make of the situation, and knew she'd have to deal with whatever was going on sooner rather than later, but surely it could at least wait until after the festival?

As she thought about it, she realized the obvious answer.

Everything had been set in motion regarding Twilight and the festival, and Celestia could only wait for the results. She had faith that her student could get the job done, and that left the Sun Princess herself to wait for the outcome.

No, something told Celestia this new matter would end up becoming much more of a problem not too far off into the future, if it hadn't already. She flicked her ear again and frowned.

Wait... what is that sound?

Celestia furrowed her brow and turned away from the mirror of her vanity. She scanned the room, but saw nothing out of the ordinary. Everything looked as it should and she was alone, yet the sound persisted, and she couldn't put her hoof on what the sound was.

It was muffled slightly, but after a few moments of confusion, the sound gradually became clearer, and Celestia was able to identify the noise. Her ears continued to twitch and her bemused scowl deepened as she picked out the strange sound.

Is that... humming?

Indeed, it sounded like somepony was humming some sort of tune. It was a strange, unfamiliar, and haunting melody that seemed to come from everywhere at once.

It was faint at first, but slowly grew in volume, and it made Celestia's fur stand on end. Hackles raised, Celestia stood up and took a step back from her vanity, a tight frown adorning her face.

She thought to call out to the intruder, but decided against it. Instead she waited—watching and listening for anything to make an appearance. She waited for whoever had invaded to make the first move... yet, aside from the humming, nothing changed.

Then something did change.

Up until now, Celestia hadn't been able to discern whether or not the eerie, echoing voice was feminine or masculine, but then the tone shifted to a slightly deep, but still clearly feminine voice.

What's more, it was a very familiar voice—one Celestia would've recognized anywhere.

It was her own voice.

"Such a sad and mysterious tune, wouldn't you agree?"

Celestia whipped back around to face the mirror and saw herself reflected as she was. She stood, her body facing away from the vanity while her neck twisted around slightly to face that reflection.

That reflection that was so much like her, yet not at all.

That reflection that stood the same as she did, twisted around the same as she did, gave the same warm, knowing smile she herself was wont to do when addressing her little ponies.

None of this would be out of the ordinary if that reflection's expression had matched Celestia's own... but it didn't.

Celestia stood frozen, her own face was a mask of shock and confusion. The reflection turned and sat, fully facing the stunned Princess, but Celestia didn't move a muscle.

"No opinion?" The reflection chuckled airily, "that's fine, I personally hate the tune myself, but I can't seem to get it out of my head."

"Who... what are you?" Celestia asked, narrowing her eyes. She turned and took a cautious step back from the mirror, "how have you come to be here, and what are your intentions?"

Celestia had lived quite a long time, and had seen her fair share of odd and mysterious events and circumstances. Even something like this wasn't too far out of the realm of believ, but all the same, she was wary—more so than normal given what she'd seen and heard earlier.

That had been something truly out of the ordinary. She felt like she could still sense their foul aura, even from this distance. Just thinking about their horrible gaze made her shudder slightly.

"Please, Princess, I mean you no harm," spoke the reflection in a reassuring tone, "in fact, I'm here to help you, believe it or not."

Celestia didn't believe it, not for a moment. Nevertheless, she allowed the reflection to continue speaking. The reflection shifted, making itself more comfortable as it rested itself onto its stomach and wrapped its prismatic flowing tail around itself.

"I'm sure you've already noticed by now," the reflection began, "but something has made it into your world—something unnatural to your kind, something that doesn't belong, something that's causing problems even as we speak."

"Something a lot like you, I'd imagine," Celestia replied, once more furrowing her brow, "I'll ask again, what are you, creature, and what do you know of these... abnormalities?"

"I'm no one of consequence, Sun Princess," the reflection replied dismissively, "as for the abnormalities... well..." the reflection smiled thinly, "I'm afraid you're in the midst of a subtle invasion—one that's going to get a lot less subtle as time goes on."

Celestia's eyes widened slightly and she took a step back. Images of the three mares in the hospital came to her unbidden, their ominous message replaying itself in her mind.

She'd known something was amiss, and had even entertained the idea of another potential Equestria-wide disaster waiting to happen... but an invasion?

"What do you know of this... 'Dead Goddess'?" she asked, regaining her composure, "if Equestria truly is being invaded as you say, is it her that leads this campaign?"

"Oh?" the reflection replied, raising an intrigued eyebrow, "you surprise me, Princess. I doubt there are many records of her existence in this dimension. Regardless, the answer is yes, you have her to thank for the push into Equestria."

"So I was right," Celestia muttered, lowering her head with a concerned frown, "whatever this is... it is not of this world, or even this realm..."

The reflection had alluded to as much, but to have it confirmed like that...

And what of this creature in her mirror?

"You said you were here to help me," Celestia continued, narrowing her eyes, "yet you take my likeness and hide behind the veil of this mirror, and what's more, I know nothing of your origins. To put it frankly, why should I trust your word? What do you have to gain, creature?"

The reflection stared back at Celestia with an unreadable expression, then gave a long suffering sigh and rose back up into a sitting position with an impatient frown.

"Were I to reveal my true form, Princess," the reflection replied with a hint of annoyance, "even a being as old and powerful as you would most likely be reduced to a screaming, babbling idiot devoid of any semblance of sanity. If you believe anything, then believe that I contact you in this manner for your own good."

Celestia considered the reflection for a moment. She thought back on how Doctor Steady Beat had reacted once those mares had started speaking. It wasn't all that hard to believe, so Celestia let it go for the moment, but there were still many questions left unanswered.

"As for my motivations," the reflection continued, "I simply don't want to see our worlds mix. I'd rather everything remain as it is—uphold the status quo as it were, and there are forces at work that seek to change that for the worst."

"Such as?" Celestia pushed.

"Our beloved dead goddess for one," the reflection replied, shrugging it's shoulders, "she's already made her way here, and as you've no doubt already seen, she's already worked her... ah... magic on your fair equine subjects.

"As I've said before, it's not me you need to worry about—not when the real threat is already on your doorstep. I tried to stop her from leaving, but it seems I'm unable to enter your world. As things stand now, I can only warn you from beyond this 'window'."

"And do you know where she is now," Celestia asked, taking an urgent step forward, "what does she look like? Do you know what her current plans are?"

"For now, I believe she means to turn your subjects into hers," the reflection answered, sitting back up with a serious frown, "make them into something horrid and unnatural by your world's standards, and on that front she's already made a small bit of progress."

Celestia matched her reflections frown.

Celestia still didn't trust the creature in her mirror, but for the moment its info was all she had to go on, and she had no other leads and no clue where to even begin searching for any.

If the creatures words were indeed the truth, then she had less time than she originally thought. It was a gamble, but she really had no other choice at the moment.

"Is there any way I can reverse whatever she's done to my little ponies?" she asked worriedly, "can I still save them?"

"No, you can't," the reflection stated bluntly, "once they've been Awakened, there's no going back to being a simple pony, and the longer the Awakened remain in her presence, the more they... change."

"Change?" Celestia questioned, "change how?"

"Oh trust me, Princess," the reflection replied evasively, "you don't want to know. Let's just say, that it'd best to stop this fiasco sooner rather than later."

"I... see..." Celestia muttered, hanging her head, her ears folding back against her head. She stood in a sullen silence for a brief moment before her ears perked up and she stood a bit straighter, "then there's no time to waste. I must find this 'Dead Goddess' and put an end to this madness before it truly begins."

The reflection gave an amused chuckle and shook its head at Celestia's words. Celestia frowned, but the reflection didn't elaborate, instead opting to move on.

"And on that note, I suppose I should actually tell you where—or rather who the dead goddess is," the reflection responded, "you see, in order for any of our kind to survive in your world for any period of time, we need to take on a host, and if you want to know who the host is..."

The reflection paused just as an urgent knock sounded from the bedroom door behind Celestia. She gave no visible response, all of her attention fully focused on the reflection's next words. The reflection smiled a wicked smile and ice cold dread flooded Celestia's veins.

She knew.

Somehow she'd realized it moments before the reflection had even spoken her name. It made no sense, and yet, for some reason, to Celestia at least, it made all the sense in the world that it was her.

The necrotic aura Celestia had been feeling in the back of her mind suddenly pushed itself to the fore, causing the Solar Princess to shiver involuntarily.

Another knock, this one more urgent than the last and accompanied by a panicked plea to open the door. Celestia continued to ignore it as the rest of her world drained away, leaving only her, the creature that was her reflection, and its next words.

"...you need look no further than Twilight Sparkle, your own faithful student, Princess."

Somewhere in the distance there was a deep sigh, and the mountain rumbled.

Author's Notes:

For those wondering what Celestia was up to.