If anyone told me earlier that I would have to live like that, I would have laughed in their faces. I guess I'll never be able to, mused a young woman in her mid-twenties with unusual fiery-red and yellow hair.

Her name was Sunset Shimmer.

And the words "live like that" meant "live in the post-apocalyptic irradiated wastelands".

How, you ask, did it come to this?

Politicians' stupidity, Sunset would say.

Someone else may be more elaborate and tell a mini-story.

The wastelands Sunset Shimmer found herself in are all what remained of a powerful country known as United Federation of Equestria, or UFE for short.

Pretty ironic that this country in the parallel world bears the name "Equestria" as well.

The country owed its name to the fact that horses of various kinds were highly venerated among the inhabitants of the continent where UFE eventually rose. The equines helped a lot against dangerous beasts that used to prowl the lands, and against some medieval invaders that were defeated thanks to the fact that they never had horses of their own and did not have the tactics necessary to defeat the natives; thus, many cities bore "horse-names", and eventually they all united under the banner of UFE.

The technology went on, but the respect for equine companions prevailed among humans even in these days.

United Federation of Equestria was a prosperous and rich state, with post-industrial society and high level of life, but the prosperity came at a cost of various natural resources, like oil, natural gas, coal and so on. Unfortunately, many of these resources could not be replenished, and UFE was not the only country in the parallel human world which Sunset now called her home.

Thus, when it became obvious that the world faced an energy crisis, all countries, UFE included, tried to find a way to deal with it.

Alas, they settled on a way that Sunset's compatriots would not approve of: each country tried to hoard all resources for themselves.

UFE was not only prosperous, but also powerful, and it had a strong military. Several other countries, rich in natural resources but not as strong, feared that they would be annexed, and formed a military alliance known as TransOceanic Defense Coalition, or TODC for short.

United, TODC became a superpower which could rival UFE in strength. Both sides quickly became bitter enemies.

And the enmity led to a war between them.

Both UFE and TODC hoped for a quick victory over each other, but the hopes were dashed pretty quickly. While UFE held an advantage in terms of military technology and number of soldiers, TODC had some unique armaments and unconventional tactics of their own, and war came to a stalemate.

The rate at which natural resources were draining rose even higher. In the end, one of the sides (no one knew whether UFE or TODC were to blame for this) had enough, and unleashed the most powerful weapon one could conceive: atomic bombs. And the other side responded in kind.

The result: many cities were burned to the ground, the land masses were irradiated, millions of people perished, and United Federation of Equestria, as a state, ceased to exist.

Some of the people, however, were able to save themselves in underground bunkers known as "Vaults". Built by Vault-Tec, a well-known pre-war company, these bunkers could shelter their inhabitants from nuclear disaster, and provide them with clear water and other necessities for survival. One could live there for years.

Even then, there were simply not enough Vaults to shelter the whole civilian population of UFE. Sunset Shimmer was lucky enough to get a place in one of them - Vault 75.

Seven years after the disaster, however, the inhabitants of Vault 75 left it: surface radiation levels unexpectedly dropped faster than anticipated, and it became possible to live outside. As such, the Overseer of Vault 75 felt it safe to come out.

How wrong he was.

While not everyone who lived on the surface before atomic strike perished, many lost whatever dignity they had. Vault inhabitants who wanted to try and co-exist peacefully were attacked by raiders (people who had no sense of morals whatsoever), and the Overseer was killed.

The revenge attack led by Vault 75 security personnel on the raider village resulted in majority of officers getting killed, but they took out each and every raider they could in a pyrrhic victory. The survivors occupied the houses previously used by these dregs of post-apocalyptic society, and helped themselves to raider weapons.

Thus, Vault Village was born.

And Sunset Shimmer lived there.

Alone.

Before the apocalypse, she lost contact with her friends. She had no idea if they were even alive, but she always remembered their names.

Applejack. Rarity. Rainbow Dash. Pinkie Pie. Fluttershy.

Princess Twilight Sparkle.

Sunset shed a tear (which she rarely did; Wastelands did not tolerate weakness); she lost her magic book in a hurry to get into Vault 75, and she could not tell her royal compatriot what had happened.

She did not even know if the book survived atomic fire.

Sunset did contemplate to find the magic portal and go back to Equestria; but it was very likely that Canterlot High School and the portal were destroyed by nuclear bombs.

Meaning I am trapped here forever. Getting through the Wastelands to CHS would be a fool's errand anyway. Too big of a distance through the land filled with mutants, wild beasts, raiders and Celestia knows what else.

Sunset entered her house and went upstairs. Before going to sleep, she put her hunting rifle nearby.

You never know when you need a weapon in the Wastelands...

Ding-ding-ding-ding-ding-ding-ding-ding!

The annoying sound of metal hitting metal snapped Sunset Shimmer out of the dreamscape. After a split-second of unwariness (Wha? What happened? What's the commotion about?) she noted that the sun was still below the horizon, but it was not pitch-dark outside (Somewhere between 4 and 5 a. m., it seems), and she also noted the sound of gunfire.

Gunfire?

Any remnants of drowsy state disappeared as if washed away by a bucket of cold water.

The village is under attack!

Sunset immediately grabbed her hunting rifle and dashed downstairs. On the way to her front door she managed to check whether the gun was loaded (it was) and flip off the safety, making the gun ready to fire.

The fiery-haired woman opened the door - to be greeted with a hulking scorpion-like figure mere few meters before her.

Fortunately, the radscorpion (as these creatures were known) was turned away from her, and it was distracted by several men in the uniforms of Vault 75 security firing at it.

Sunset did not think twice before taking aim at radscorpion's "back" and firing. She was by no means an expert (not being one of security personnel, she, like any other Vault Village inhabitant, had only a month of experience in gun-firing), but missing at this distance was nigh impossible.

It was also impossible not to attract radscorpion's attention this way.

What. An. Idiot, the little voice told Sunset Shimmer reproachfully, as she moved the bolt, preparing to take another shot.

Need to act quick!

Before radscorpion came close enough for an attack, Sunset fired another shot. The bullet entered radscorpion's body (Blast! I was aiming to hit the eyes!), inflicting some damage, but not killing it. Radscorpions were tough to kill if you were not experienced enough, and security personnel rarely engaged one without arming themselves with assault rifles, and only if they had advantage in numbers.

The fiery-haired fresh-out-of-the-Vault Wasteland inhabitant had neither of those, and instead of wasting time to prepare another shot, she bolted back into the house and closed the door, locking it with a mere block of wood.

BANG!

The radscorpion apparently did not slow itself in time. Sunset moved to the side (standing in front of door that may get demolished by a mutated monster is pure idiocy, after all) and prepared another shot.

CRASH!

Radscorpion's tail made a hole in the door (great, now I'll have to repair that!), its poisonous tip in the place where Sunset's head was mere moments ago. Before the beast retracted it, Sunset managed to put the business end of her rifle to it and fire at point-blank range. The resulting BOOM was deafening, almost drowning out radscorpion's screech of pain.

Brat-tat-tat-tat-tat! BANG!

Unmistakable sounds of assault rifle and combat shotgun preceded the mutated animal's screech of pain, before its still-stuck tail twitched one last time and dropped lifelessly.

Just like in all bad action movies, last second rescue. But cursed if I am not glad.

"Miss Shimmer?" Sunset heard the voice of one of security guards, Swift Sentinel. "Hello? Miss Shimmer, are you alright?"

"Yeah," she replied, shaking a bit as adrenaline in her system went down, "yeah, I'm fine. No scratches. You boys came in the nick of time."

"Glad to hear it. Miss Shimmer, we really hate to ask you this, but could you please help us?"

Wow, it appears to be serious. Guards don't ask for armed civilian's help unless it's bad, thought pony-turned-human. She unlocked the door and came out (not without some difficulty - radscorpion's corpse presented a problem), face-to-face with her saviours.

"How bad is it?" she addressed Swift Sentinel, who just finished reloading his assault rifle.

"Half a dozen radscorpions went on a rampage and came to the village. We downed four of them, this one included," he waved his weapon's barrel in direction of freshly-killed monstrosity, "and two still remain in southern outskirts. Other guys can't handle them on their own, too lightly armed."

"Fine," Sunset replied, "I'll help. Just need to reload my rifle."

"Reload on the run, if you please. Follow us," the guard said and turned into the direction where they needed to go. His partner and Sunset followed him without further word exchange.

Unfortunately, this situation was not entirely unusual for Vault Village. The raiders chose an imperfect (to put it lightly) location for their base, which was close to habitats of various mutated beasts, and when security personnel of Vault 75 eliminated all of the raiders they were able to get to, they became a target of beasts' rampage instead. Fortunately, raiders had a decent enough arsenal, which was quickly put to use, but there were too few guards left to properly defend the village on their own, and it was decided that villagers should be taught self-defense with firearms.

The results were, shall we say, imperfect. While this decision boosted Vault Village's defensive capabilities, barely trained militia also took casualties against monsters and those raiders that survived the attack on the village.

Sunset Shimmer felt uneasy about this development, at least initially. Ponies rarely killed, even in self-defense, and mostly fought only if they had no other option. And in fights, they sought to incapacitate, not to kill. Wars were extremely rare in history of Equestria, and while border skirmishes happened from time to time, diplomacy virtually never failed ponies. Even before her reformation, Sunset never sought to kill someone, with one notable exception of trying to dispose of Twilight Sparkle when she turned into a raging she-demon. This added to her hesitation of using firearms with lethal intent, even in self-defense.

Alas, horrifying deaths of other people at hands of raiders and claws of mutants quickly taught her that deadly force often served as not the last means of saving her life and those of her neighbours, but the only one. And if there was one thing that Sunset Shimmer did well, it was learning. She was not Celestia's personal student at one time for nothing, after all.

And so, she went with the guards to lend a helping hand (this phrase did not feel strange to her anymore; she did not even think of saying the word "hoof" instead of "hand") to others.

Celestia forgive me for the blood that will coat my hands, and help me prevail, so I do not fail those in need today, Sunset prayed to her ex-mentor...

Author's Notes:

As you've probably guessed, the parallel human world of Equestria Girls is not our own real world in this fic, and not the copy-pasted world of Fallout, either. I thought on this and decided that simply using the pre-history of Fallout series word-for-word is too unoriginal. (And really, can you imagine names like "Ponyville", "Canterlot" etc. IRL? I can't.) As such, expect some differences.

Still, a lot of elements of Fallout universe will be present unchanged, e.g. factions, armaments, technology and so on.

I hope you enjoyed this chapter