The music room was, without question, the most popular hang-out spot of Sunset and her friends. And yet, today, during the lunch hour, it sat nearly vacant, with it's many instruments simply placed by the side, ready to use when their owners arrived. However, the place was not entirely empty today, as there, sitting in the corner, was none other than Twilight Sparkle, a recent transfer student from Crystal Prep. At this present moment, the spectacled girl was busy, holding a notepad and writing down furiously, with a strange blush upon her cheeks as she did so. However, as she absent-mindedly chewed on the end of her pencil, the door of the room flew open. Immediately, Twilight got to her feet, hiding the notes behind her back as if embarrassed, and it was here when she realised who it was that now entered this place.
"What the...?" she started.

Looking on, Twilight noted as all of her friends from this school, Rainbow, Applejack and the rest, all came flooding into the place, with Sunset at the rear. Though curious, Twilight nevertheless gained a small smile as the girls noticed her, with Pinkie especially seeming as happy as ever to see her. However, as Sunset looked back into the hallways behind her, making sure that there was nobody else about, she finally saw Twilight, gaining a look of curiosity as she did so.

"Twilight? What are you doing here?"

Hearing that, the girl held onto her notes even tighter, her blush returning from earlier as she attempted to answer.

"Well...um...I was in the middle of research and...well...I felt like I just needed a quiet place to do it."

Sunset raised an eyebrow, already feeling suspicious about the way in which the girl had answered her. The others too were curious, though they remained silent, instead watching as Sunset began to approach the former Crystal Prep girl.

"Twilight...this research? It wouldn't, by any chance, happen to be of a...personal nature, would it?"

Twilight looked to her, at the almost-piercing gaze Sunset was giving her, and found herself stunned. Though the words had undoubtedly been vague, there was just enough of an edge to them so that, in an instant, Twilight understood the subtext behind Sunset's question. And yet, there was no sense of accusation behind them, merely curiosity and concern, which, over time, led the girl to eventually nod, still looking hesitant to do so. Slowly, she brought out her notes, causing Sunset to regard them carefully, before nervously behind handed them by Twilight. With a grateful expression, Sunset accepted, and soon began looking over the notes. As time went on, and the other girls were looking increasingly impatient, Sunset's expression changed many times, eventually settling on what seemed to be acceptance, as evidenced by the sigh she let out.

"I thought so. You too, eh?"

Twilight, adjusting her glasses, gave a brief nod. Sunset, maintaining a neutral expression as she finally turned to face the other girls, and it was here when Rainbow, tapping her foot against the ground, finally spoke out.

"Okay, are you gonna tell us what's going on or what?"

Sunset exhaled deeply, looking pretty concerned throughout. Her eyes, for a moment, seemed hesitant to look at her friends, but, in the end, she finally got her words out.

"This...this is going to sound incredibly invasive on my part, but...I want you all to think back over the last year. When was the last time any of you experienced...well...your time-of-the-month?"

Immediately, the room broke out into all of the myriad expressions Sunset expected, from surprise and shock to such a bold question, to outright disgust and embarrassment. Many blushes and avoided gazes were had as a result of that question, not to mention a deep and uncomfortable silence. But, after a good long while, it was Rarity who finally broke the silence.

"My dear Sunset! What on earth would make you ask such a question?"

Sunset turned to her with a look of utter seriousness.

"Trust me on this Rarity. Because if I'm right, it's very important for me to know."

Rarity, much like the rest of the girls, seemed sceptical at such a statement, and yet, if only to humour their friend, they stopped and considered the question for a moment. Another silence followed, during which, many of the girls, perhaps as Sunset expected, began to look curious, and then confused, looking to each other to gauge each other's reactions. Eventually, and after a great deal of hesitation form all of them, it was Applejack who spoke up next.

"Well...actually...now that ya mention it...ah don't think ah've had mine since...since..."

But Sunset finished her words for her.

"Since you first ponied up?"

Applejack closed her mouth, giving a single nod in response, prompting Sunset to sigh.

"I thought so."

Rainbow took a step forward, frowning slightly and placing her hands upon her hips as she spoke up.

"Okay, that's it! Enough mystery already! What's going on, Sunset?"

For a moment, there was another silence, and Sunset looked over to Twilight, who seemed just as reluctant to speak as she did. However, after giving each other mutual nods, Sunset looked back to her friends and started speaking.

"I've had my suspicions, but...after recent events, I think it's pretty much confirmed. Our use of Equestrian magic has...changed us."

The other girls all took on looks of confusion, with the exception of Rainbow.

"What, you mean like when we grow wings and stuff?"

Sunset shook her head.

"Not just that. I think...I think the Equestrian magic has altered our bio-chemistry, making us more akin to the ponies of Equestria. At least...one part of our biology."

Raising a hand, Rainbow grabbed the bridge of her nose and groaned a little.

"Ugh! In English, Sunset!"

Taking a deep breath, Sunset gave the direct answer that was demanded of her.

"Girls...I think...we've all gone into heat."

The silence that followed was one that, if anything, utterly dwarfed the ones that had come before. All of the girls, as soon as they'd heard that, stood as still as statues. So silent was this room now that, had a pin dropped, it would have sounded like an utter clamour. They looked to Sunset, bearing looks that made it clear that they were hoping desperately that she was joking in some way. But, as the silence continued, and Sunset maintained that look of seriousness, they knew, in their hearts, that this was no joke on her part. Slowly, they began to look at each other, except for Fluttershy, who had taken to hiding her face behind her long, pink hair. A good deal of time finally passed before someone said anything, and, as before, it was Applejack.

"Um...heat? Ya mean like...?"

But, again like before, Sunset spoke her words for her.

"Yeah...mating season for ponies."

The girls continued to stare at her, perhaps out of some need for further explanation, or maybe in the hopes that, if they stared long enough, they'd all just wake up form whatever bad dream this was for them. Sunset elected to go the former route, and so cleared her throat a little before starting to explain things further.

"Look...back home, in Equestria, once a year, mares would go through a period of about two weeks when their bodies would basically encourage them to find a mate and, well, you know."

The blushes that crept onto all of their faces made it obvious that they did, indeed, know. Seeing this, Sunset continued.

"There's a lot of technical stuff about it, but, bottom line, their hormone levels would shoot through the roof and they'd be more, for lack of a better word, affectionate than normal."

At long last, somebody spoke amongst the other girls, and as before, it was Rainbow.

"That...that...that sounds like the lamest porno story ever!"

Instantly, all eyes were on the athlete, with Rarity especially looking astonished by such a remark.

"Rainbow!"

Turning to her, Rainbow shrugged her shoulders.

"What? You're all thinking it! A group of young girls all getting hit by some magical whatever, making them all horny and stuff? That sounds like the start of every single badly-written fantasy porn out there!"

Looking to her with a raised eyebrow, Applejack replied to that.

"And how, exactly, do ya know what a bad porno look like?"

Looking back to her, Rainbow gained a somewhat mischievous smirk.

"Let's just say my old friend Gilda wasn't as clever with her hiding places as she thought she was."

Most of the girls, understandably, simply shook their heads in a vain attempt to get that particular train-of-thought out of them as fast as possible. But, after yet another pause between them, another of their number spoke up to Sunset, though to her surprise, it was Fluttershy.

"And...um...you've...you've been through this before?"

Sunset gave a nod.

"I did. Back home. But ever since I came here, well, it's been replaced with what human girls go through instead, at least, until now."

Folding her arms, she turned away from them and took on a ponderous look.

"To be honest, I've never been able to decide which was worse."

As she turned back to them, it was Rarity who spoke next.

"And...you believe we're all going through this...heat?"

Again, Sunset nodded.

"I think, when we all used our Equestrian magic, it changed us, made us closer to ponies on the inside, as well as the outside. Changed us to the point that, now, we have reproductive cycles more in-line with what those in Equestria have to go through."

At that, Rarity looked utterly aghast, flinging the back of her hand up to her forehead, and began speaking out in that dramatic was she was so known for.

"Oh! This is terrible news! This is it! This is the end!"

Sunset raised an eyebrow at that.

"Rarity..." she started.

"I'm going to end up in a one-night stand with some stranger!"

"Rarity..."

"I'm going to be with child! I'll turn into one of those too-young mothers and end up on one of those dreadful talk shows!"

"Rarity!"

The young fashionista was taken aback by Sunset's suddenly aggressive tone, but the latter, taking a few calming breaths, took a few steps closer to her, holding onto her hand and trying to look as reserved as possible.

"Rarity...none of that is going to happen."

Rarity, looking quite hopeful all of a sudden, spoke to her with a somewhat shaky voice.

"It...it's not?"

Smiling, Sunset shook her head.

"Not if I have anything to say about it."

Placing a hand upon Rarity's shoulder in an attempt to further calm her, Sunset then looked to the rest of her friends.

"Look...I know you're all worried about this, and I can completely understand that. This is new territory for all of you, but I promise I can help you through it."

Raising an eyebrow, Rainbow took on a more sceptical look as she regarded her friend.

"No offense, Sunset, but how? I mean, according to you, we've all got this crazy magical mumbo-jumbo going on that's gonna make us wanna...ya know...hit the sack and stuff."

Needless to say, Fluttershy, upon hearing that, took to hiding her face again, all while Sunset gave Rainbow her response.

"I know. But, back in Equestria, there were many ways by which young mares, like me, could help to avoid all that. We never had contraception, at least, not like this word does, since pregnancy only ever really occurred during heat. But, we did have means to lessen the effects of heat, and dull it's edge to the point where we could control it."

As one would expect, all of the girls turned to her with hopeful looks, with Applejack stepping forward next.

"Okay then, Sunset. If ya say ya can help us, then we'll wait fer ya."

Sunset smiled, looking more than a little appreciative of that, especially when she looked around, seeing similarly-trusting look from the rest of her friends. However, before she could say or do anything, she was interrupted by the sound of knocking on the door. Sunset, like the rest of the girls, was both taken aback and confused by this, but the former nevertheless walked over, turning the knob and opening the door. There, on the other side, a familiar, blue-haired face was smiling back at her.

"Hey there, Sunset," Flash remarked.

Smiling a little, Sunset responded.

"Hi, Flash."

But, as soon as her smile had come, it vanished, replaced instead by a look of shock and realisation.

"Gah! What...what...what are you doing here?!"

Flash was a little confused as to this reaction from his friend, but even so, he gave his answer.

"Well...um...Rainbow invited me?"

Immediately, Sunset turned to the girl in question, who only now took on a look of realisation, slapping her forehead as she did so.

"Argh! Right! Guitar practise!"

Flash nodded at that, patting the guitar case he was carrying in one hand.

"Yep. So, is this a good time, or...?"

Looking back to him, Sunset seemed to mentally debate with herself for a few moments before letting out a sigh.

"I'm sorry, Flash, it's just that-umph!"

To Sunset's shock, a familiar blue hand clasped over her mouth, with Rainbow now standing to one side of her and nervously chuckling at Flash.

"Could you excuse us just one minute, Flash?"

To that, Flash simply shrugged his shoulders and nodded, prompting Rainbow to smile back at him before dragging Sunset off to the side. There, the other girls congregated around them as Rainbow finally released her. And while angry, Sunset nevertheless kept her voice down to a hush as much as possible, lest Flash hear them.

"Rainbow?! What are you...?"

But Rainbow soon interrupted.

"Look. We don't want Flash or anybody else getting wise to what's going on right now. I mean, can you image what would happen if this kinda thing was leaked to anybody else? If we start cancelling plans and stuff, people are gonna start suspecting that something's off."

Sunset rained an eyebrow, but looked around as Rarity then added her voice to the mix.

"While I'm usually loathe to agree with Rainbow on most matters, I feel that, in this case, she has a point. Discrepancy is probably the best course of action."

Sunset looked around at the rest of the group, to Twilight, Applejack, Pinkie and Fluttershy, and saw that all of them seemed to be in agreement over this. Thinking over the matter for a bit, Sunset eventually let out a long sigh before giving a nod, consenting to the matter.

"Alright. We'll keep going on as normal for now."

But, she soon looked up more seriously to Rainbow.

"Rainbow...are you sure you're going to be okay here with him?"

To that, Rainbow snorted a little.

"Please, Sunset! I've gone pretty much my whole life without ever chasing a guy. I think I can handle being around Flash until you get that medicine or whatever sorted out."

Again, Sunset seemed thoughtful, and again, she gave a nod, agreeing to Rainbow's position. The group then parted, looking over to Flash, who seemed to be patiently waiting at the door still.

"So...can I come in?"

The girls all looked to one another for a moment, culminating in Sunset speaking up for all of them.

"Sure."

Smiling, Flash began walking over to one side of the room, wherein he started setting up his guitar. The girls all gave one final glance to each other before, in the interests of secrecy, starting to make their way out of the music room, leaving only Rainbow behind for her pre-arranged guitar session. For a brief moment, Sunset gave a glance to her friend, which was responded to with a casual thumbs up by the latter. Smiling, Sunset joined her friends and left the room, closing the door behind her as she did so. Once outside, she looked to each of her friends, and after a while, they nodded to one another, before starting to part ways. Once alone, Sunset looked over in the direction of the library, a look of determination upon her face.

"Okay then...time to get to work."