Once upon a time, in the magical land of Equestria, there were two regal sisters who ruled together and created harmony for all the land. To do this, the eldest used her unicorn powers to raise the sun at dawn. The younger brought out the moon to begin the night. Thus, the two sisters maintained balance for their kingdom and their subjects: all the different types of ponies.

But as time went on, the younger sister became resentful. The ponies relished and played in the day her elder sister brought forth, but shunned and slept through her beautiful night. One fateful day, the younger unicorn refused to lower the moon to make way for the dawn. The elder sister tried to reason with her, but the bitterness in the young one's heart had transformed her into a wicked mare of darkness: Nightmare Moon. She vowed that she would shroud the land in eternal night.

Reluctantly, the elder sister harnessed the most powerful magic known to ponydom: The Elements of Harmony! Using the magic of The Elements of Harmony, she defeated her younger sister and banished her permanently in the moon. The elder sister took on responsibility for both sun and moon and harmony has been maintained in Equestria for many generations.

But on the longest day of the thousandth year, the stars aided in Nightmare's escape and she sought to bring about nighttime eternal.

The elder sister, despite her great power, was no longer able to wield the elements. However, she was wise, and was able to bring a group of ponies, each a master of an element, in order to stop Nightmare. Together, the six friends were able to banish Nightmare, not only from Equestria, but from the younger sister, allowing her to raise the moon once again.

But Nightmare was not gone forever. Nightmare can not be destroyed, only driven back. And after a relatively brief wait, it was ready to return

-Fifty Miles West of Fillydelphia -

Though it may come as a surprise to Canterlotters and Manehattenites, there is more to Equestria than a few major urban centers and some forests on the horizon. One particularly picturesque example was Manenonite country to the west of Fillydelphia. Admittedly, the locals lived simple lives, forgoing modern conveniences like trains and electricity in favor of a more humble existence. However, there was something to be said for the plain elegance of rising at dawn, working to farm wheat, corn, mushrooms, and rocks for hours on end, doing one's best to maintain the home, and resting immediately afterwards. Few would call this a fun life, including the residents, but thousands would attest to it being one of the most satisfying forms of existence a pony could hope for.

It is on one of these farms where our story begins. A rock farm, to be precise. Here, two earth ponies, a mare and a stallion, had lived for decades, living off the (metaphorical) fruits of the Earth. Rocks weren't the best choice of food, but were always in demand in the cities, where good building material was always in demand. Plus, the occasional rock would grow into a fine geode, a fine delicacy which various species throughout Equestria would pay small fortunes for. Combined with the nearby river that allowed for easy transportation to the city and a smaller crop of plants for subsistence, the couple managed to live a decent enough life.

Comfortable as that life may have been, it was exhausting, meaning that by the time our story began, not too late into the night, they were already sleeping in their bedroom. There was also a spare bedroom where the couple's children once lived, but all their children were grown or dead. Currently, the room was occupied by a schoolteacher, who paid a small rent in return for a place to stay and a meal every day. On another night, he may have been awake to notice our story beginning, thanks to his habit of grading his students' work into the wee hours of the morning. However, this was the summer, meaning that the colts and fillies were too busy helping their parents on their farms to go to school. Therefore, the teacher lived the same schedule as his landlords, working all day to earn his keep and sleeping at night.

This is why nopony was around to see the strangest magical phenomenon to occur in Equestria for months. Admittedly, this was not the most impressive record, but considering the abundance and power of magic in the land, a temporary tear between worlds is merely an interesting event, not an astounding one. The absence of light, from the portal itself or the moonless sky above, did little to make it more impressive.

Of course, holes between dimensions are far from unheard of in Equestria. More than one talented young unicorn occasionally would attempt a spell beyond their abilities, leading to all sorts of other places. These talented young unicorns usually died in the process. It's surprising how few dimensions have breathable atmospheres. One very lucky mare, the unfortunate bystander in an experiment, managed to return to tell the tale a few years back, but was an unreliable witness due to the trauma that ensued. She unfortunately had to leave university and eventually found work as a mailmare.

Perhaps the dimension that she visited was the one that was temporarily connected to the farm miles west of Fillydelphia. The Foreigner that exited the portal was bizarre enough to belong to an insane universe. It was hard to see, what with it being night on both sides of the portal, but based on its low and wide silhouette, though it was probably not too much larger than a pony, it bore little resemblance to them, griffins, dragons, or even mythological creatures such as humans.

The Foreigner scuttled across the farm, stopping every so often as if to investigate rocks and dead trees around it. The lack of light seemed to have no effect on it, as it moved at a regular pace except when investigating something. Eventually, it headed towards the farmers' home, barely making any noise on the hard ground beneath it. About 20 feet from the house, the Foreigner stopped, staying still for a few long minutes.

Suddenly, it rushed around the house, being careful to keep its difference. On the other side, it approached a clearing. Unlike the rest of the farm, there were no pebbles or rocks small enough to hold in one's hoof. Instead, there was just one, large tablet, sticking out of the earth. The Foreigner went straight for the rock and, after a moment's hesitation, began digging.

The hypothetical audience of the Foreigner would still have trouble making out its shape, but would begin to notice some oddities about it. For instance, every so often, a limb would fly out, tossing away dirt, and then go back towards the ground. For another thing, the air around the Foreigner seemed to shift about, as if bits of the Foreigner were always moving, regardless of the digging.

But the thing that would stand out the most to somepony watching would have to be the smell. It was not particularly noticable at first, but as the Foreigner stayed in one place for minutes on end, a sour and sweet aroma would fill the air. For a griffin or dragon, this smell would remind them of a dinner that was never eaten. For a pony, this smell would be that of death.

Finally, the Foreigner has dug itself a hole that it could fit into. For the first time, there was a significant amount of noise, that of wood being torn apart. The farmers in the house could be heard stirring. Suddenly, once again for the first time, there was a flash of blinding from the hole. There were screams from within the house, as apparently everypony had been awakened. The Foreigner meanwhile, seemed to have disappeared. In its place was a small figure, much more pony-like, that ran off into the distance.

It was terrible day for the Cutie Mark Crusaders.

It had started well enough. The three fillies, Apple Bloom, Scootaloo, and Sweetie Belle, had met at their clubhouse after breakfast to plan the day's crusading. It was Apple Bloom's turn to pick the next activity, so the trio became the Cutie Mark Crusader Barn Builders. After all, every farm in Equestria needed a barn. Best of all, this activity was both innocuous sounding enough for Sweetie Belle and potentially exciting enough for Scootaloo.

Barn Building went pretty well at first, and Apple Bloom turned out to be fairly good at designing a small barn, hammering boards together, and giving her friends the guidance necessary to put in their share of quality work. Unfortunately, it turned out that the barn already on Sweet Apple Acres was not the best source of raw materials, and an angry Applejack chased them through a hole in the side of the barn.

Next, it was Sweetie Belle's turn to pick a Crusade. She proposed that they become the Cutie Mark Crusader Spa Ponies. Scootaloo protested, claiming that a Spa-related Cutie Mark would be a terrible thing to have on one's flank, but the two eventually struck a deal: the spa would come first, anything Scootaloo wanted would come soon afterwards.

Nopony ever knew exactly what happened at the spa. Somehow, the Crusaders had been split up by the enthusiastic yet naïve sisters who ran the establishment, and wanted to show the three around. Within half an hour, the tubs were overflowing with soapy water, the floors were covered in mud, a few mares were left shrieking, and the Crusaders were covered in cucumbers.

For the record, they blamed Spike.

Despite the intensity of these crusades, it was still only early afternoon when it was Scootaloo's turn to pick the next crusade.

She chose Monster Tracking.

"Is monster hunting even a real talent?" enquired Apple Bloom.

"It should be. With all the monsters in the Everfree Forest, there ought to be somebody who can keep track of them," replied Scootaloo.

"But there are no Monster Trackers! The closest thing we have is Twilight when she's doing research in the forest, and her talent is magic."

"Then maybe our monster hunters don't have it for a Cutie Mark. Some ponies don't have obvious cutie marks for their jobs."

Apple Bloom and Scootaloo sat down, hooves on their chins, wondering to themselves who around Ponyville could be a monster tracker. Sweetie Belle, who had been staying out of the conversation, stared at the ceiling. After a few minutes, she lit up like a candle.

"I know who tracks down monsters around here!"

"Sweetie, we've told you, the doctor is not really a-"

"No, not him"

Lyra Heartstrings was in what Rarity might have called "The Zone." Artists like her often had trouble creating new work, but for once, she was inspired. The notes were just coming out of her mind, into her horn, and through the lyre. Note after note flowed through her soul, as she constructed a melody that she could play for years to come. Nothing could stop such majesty! Not a th-

Ding Dong!

And with that, Lyra had left The Zone and ended back in the kitchen, sitting with her rump on a stool while her forelegs supported her lyre on the table. It was good while it lasted.

"Bon Bon!" shouted Lyra. "Somebody's at the door!"

Lyra's marefriend came running down the stairs and to the door. Lyra smiled to herself. The two of them had an understanding. Lyra took care of business while Bon Bon was inventing new sweets, and Bon Bon took care of business when she was composing.

Lyra pulled herself together and tried to get back into the zone, but soon became aware that she was being watched. Behind her were Bon Bon and three smiling fillies, trying their very best to contain themselves from shouting something. Sighing to herself, Lyra turned around to face them.

"These are the Scootaloo, Apple Bloom, and Sweetie Belle, remember Lyra?" asked Bon Bon

Scootaloo bumped in. "We are the Cutie Mark Crusaders and we're on a quest to find out our talents and we thought that you could help us because you track monsters in your free time and we thought you could show us how so could you take us monster tracking please?"

For a moment, Lyra was silent. She pointed her head towards the floor. Bon Bon began to frown, and the Crusaders' smiles faded somewhat. Then, Lyra began to speak.

"…did you say monster tracking? Young ladies, I don't know who you've talked to about this, but I have no interest in tracking down monsters. That Ursa Major a while back terrified me, and I have no desire to find chimeras or manticores. So I'm sorry, but I can't help you."

"Aw shoot," said Sweetie Belle. "We were hoping you could go human tracking with us and-"

"DID YOU SAY HUMAN TRACKING? Oh my Celestia, I LOVE HUMAN TRACKING!"

"Here we go" sighed Bon Bon.

Lyra opened a nearby drawer, and pulled out a map of the Ponyville area. It was covered with various markings and notes, decipherable only to insiders or the most determined of researchers.

"I have spent five years tracking down human activity in the area. They don't like to be seen by ponies anymore, but I believe they still check in on us every so often. Now, according to my calculations, most of the humans tend to appear around here, in the library, here, in the Everfree region, and here, east of Sweet Apple Acres. Celestia wants to control our affairs with the humans, so she sent one of her agents to secure the most vulnerable spot in town, the library. HOWEVER, the area east of the Acres is mostly unguarded, meaning I've been able to track human activities in that area. And just last week, I believe I discovered a human footprint. But I need help covering the whole area. Do you three think you could help me look for signs of human activity?"

"YES! CUTIE MARK CRUSADER HUMAN TRACKERS ARE READY!"

"Great, then we can start sometime next weekend."

…

"But miss Lyra," whined Apple Bloom, "we want our cutie marks now."

"I know you do. But I have to prepare for my concert tomorrow, and I want to surprise a certain mare with a romantic night out."

"And who would that be?" Bon Bon asked jokingly.

"Oh you know. A sweet lady friend of mine. Has trouble remembering her neighbors sometimes. Has a sweet flank."

"I hope you two have a good time," Bon Bon warmly replied.

Lyra gave a gentle kiss on the cheek. "Be sure not to tell her what I'm planning."

"Oh don't worry. She'll be absolutely shocked"

The Crusaders watched the sickening display of affection with growing disgust. Lyra remembered her audience, and pulled herself away from her love for a moment.

"Uh right. Anyhow, meet me here 8:00 next Saturday, after you're done with school for the week."