Ok to quote sans here "Lets just get to the point" this story is actually a crossover of sorts, more specifically between Fallout and UnderTale; and i actually have no clue what i am doing because i haven't beaten UnderTale yet and i have been completely spoiled as far as the endings are concerned. But I know fuck all about everything in between so all my information I got is coming from a few undertale FanFiction's I read so yeah.

Anyways, i liked UnderFell so much that i wanted to write a fanfiction for it and i liked Fallout so enjoy my attempt at making a story that crosses them over sorta. Anyways, the story might seem a bit rushed for this chapter, thats cause this chapter is more of a 'proof of concept' sorta thing, if more people are interested i will work on the story; only reason its here and not in crossovers is because more recognition ya know?

please read, review, and please tell me where i need to improve as it will help this story.

War, war never changes.

A phrase that many are familiar with by now, since the dawn of human time; when our ancestors learned of the killing power of rock and bone, blood had been spilled in the name of everything imaginable: for the sake of war, for god, to justice to simple, psychotic rage.

Many times during these times of war, we more or less remembered our enemies; sometimes the enemies have forgotten us when beaten and sometimes our enemies history is forgotten: completly overshadowed by the history of the victor.

In a age long since forgotten there existed a species simply known as Monsters capable of using tricks from making the ground shake, to creating flames out of mid-air known as only magic; and yet despite their skill in magic humanity had defeated these monsters sealing them away in Mount Ebot. Away from the river of blood spilled by the destructive nature of man, unaware of the great war of 2077 when fire had consumed the world destroying most of the land above, and leaving mankind devastated but not destroyed.

However it was not the end of the human race, instead many survivors decided to try and learn from the mistakes of their ancestors; to build towards a better future for mankind, perhaps some soul shall be lucky enough to find this long lost civilization of monsters one day and maybe the monsters long since forgotten to time shall be a step forward to rebuilding what humanity has lost.

Perhaps these monsters will not help humanity, nobody knows for certain because war, war never changes.

Under The Fallout

Chapter 1 Fallen

'Shit shit shit shit!' Was there only thought as bullets whizzed by their head, the thundering echo of gunshots still roaring loudly as ever but not as loud as the multiple voices that were screaming at them. Of course it wasn't exactly their fault you see; they always had a hard time trying to do the right thing in a very fucked up world, course stealing someones food even if it is irradated garbage that might have a possibility to kill you is still probably not a smart move.

Especially when it was meant to be split up for a small group of mercenaries.

'Whoosh!' Another bullet sped past their head and into the tough rocks next to them, in terms of how fucked their situation was they would say their situation would be 'total fubar'

"Just a bit further wanderer you can do this you can..do..this" Their words died when they saw that there was just a cave that they had climbed into while dodging enemy fire. The problem was as spacious as this cave was it wasn't exactly a good spot to hide out or even run from since there's 1 way into the cave; and no way out of the cave. Minus a hole in the ground that could remind you of Alice In Wonderland; and finally the rest of those bastards were about to jump them.

"Ah fuck"

The wanderer quickly turned just in time for those brutes to walk right into the cave, the world went by in a blur, the familiar thundering sounds of gunshots rang in their ears, the sounds of yelling and swearing were almost loud enough to distract them from the sight of the world tilting .

They didn't even recognize they were falling down that same hole, or how truly far down the rabbit hole they were going as darkness took their vision….

The human let out a gasp as they woke up, letting that sweet air into their lungs again. This sensation of they are alive didn't last too long as they let out a groan in pain, remembering all of their injuries...and let out a small yelp in pain as they tried to get up.

"Oh hello pain my old friend, how I have not missed you in the slightest" they spoke as they tried to stand up, just barely able to stand not even properly but enough that they could walk at least with a limp.

They took the time to look at their clothes a little noticing how their favorite vault101 jumpsuit was still attached to them although in a battered status, thankfully the glove on their right hand was still intact. They had a duster on them going down to their legs, and their mountain shoes seemed to oddly fit well with their current clothing. Not that they were complaining as style was the least of their worries, like if any of the gear in her backpack was busted; or worse the miniature computer wrapped around their right arm commonly known as a pip-boy.

They shook their head before looking at the ceiling as they drew their 10mm pistol from their pocket, the familiar cold steel feeling great on their hands again. But what should have felt even better was the feeling they survived, and yet...that feeling was replaced by confusion of 'how?'.

"How the fuck did I survive that kind of a fall?" They said noting that the fall by all odds should have killed them, perhaps it was the flower bed that stopped them from dying? Though that thought didn't seem logical, or maybe it was the bits of blood seeping from their injured right arm; and maybe the head injury doing all the talking.

"It sounded like it came from over here" a voice? In English? That means that there are people down here oh looks like their luck was turning around after all!

"H-Hey c-can you help me out I'm a little hurt and-" They let out a yelp as they tried walking forward and feel to the ground letting out a hiss in pain, the blood coating one of their eyes as they layed their trying to keep focus on the voice ahead of them as the figure walked into the room.

"What the hell?" Was their response as they noticed a rather humanoid looking goat teenager of terms of height the human reached up too the goat's chest kinda made them only slightly more intimidating if they didn't look sofucking adorable. The goat seemed to walk and talk like a normal human, their shirt being red with black stripes, and they seemed to have horns on their head and wore black pants. The goats long floppy ears could only add to the cuteness factory, and those fangs didn't seem to help make him intimidating..though the yellow eyes and red iris in both eyes certainly tried to help.

"Well...fuck"

Asriel didn't know how to react to the human on the floor, he had been told by his parents over and over again that humans were the enemy and needed to be killed on sight. Well, at least his dad had told him so often throughout the years, his mother was more reluctant to teach him anything about humans and let his father do it for her.

He had been told that humans could disguise their emotions at any point in time, and judging them by appearance can prove to be a fatal mistake just as much as getting close to one.

But this human, it didn't seem like a threat to him, their injuries are severe to the point it was painfully obvious to him that this human couldn't be a threat to even a froggit.

Then they moved again.

This time they started twitching at first, as if trying to get used to movement again after staying immobile for a while. Before they tried to push themselves up from the ground as if they were attempting a push-up of sorts, before their arms gave out from their injuries and they flopped onto the ground with a groan.

It was a impressive and slightly pathetic sight to the prince.

"H-help me...please?"

Please?

Asriel's ears would have peeked up if they were able too as soon as he heard that word, please was not a word that was commonly used down here in the underground; a world where being nice like that can be seen as a weakness to many of the monsters in the underground. And down here, having a weakness means others can take advantage over you.

But when was Asriel ever going to get a chance to own a human?

The mere thought of having a human to boss around and give orders to made him feel a bit giddy inside; the other benefits started to pile up in his mind before shoving them aside to focus on his primary goal at the moment.

He calmly walked over towards the human, whom growled in pain as they once again tried to stand up, and like before they failed the goat monster couldn't help but be impressed with how they were trying their best to get up from the ground despite their injuries. Perhaps the stories about humans being tough were true after all, then again humans were the ones who had trapped them down here in this forsaken hole.

At the thought of the hole he had looked up from where they fell, the young prince had to admit this human was lucky enough too only have a messed up leg from a fall like that. A fall that would most certainly kill more than a few of the monsters down here, made him wonder how lucky a human can be.

"M-mi-mind helping me up? D-don't think I can walk by myself" They admitted with a tone that had underlines of 'you don't help me I will get up on my own' something Asriel chuckled at as the goat monster reached down and helped them to their feet. He let the humans arm wrap around his shoulder, God humans were heavy or maybe that he eight was from the strange bag they were carrying as well?

Once he had gotten the human's arm on their shoulder he was able to get a closer look at those injuries more specifically the big spot of blood on the humans chest. That wouldn't do if this human was going to be his pet, with a small sigh and closing his eyes to concentrate a small green fireball had formed in the air just long enough for him to push it right into the humans chest.

The response was instantaneous as the human let out a loud yelp in pain from the steering heat in their chest for a brief moment. They didn't know about the magic healing their worst injury apparently, then again considering how long monsters have been down here it wasn't a suprise they didn't know Asriel had thought to himself.

"Wh-wha-what the fuck was that?" The human gasped out once the pain disappeared and the burning in their chest was gone.

"Magic, all the monsters down here can do it now shut up and let's go" Asriel said with a blunt tone just wanting to get out of the ruins as quickly as possible, that and they oddly found this humans voice irritating for some reason.

"Lead the way then" That was the only 4 words they said as they began traversing the ruins; Asriel couldn't help but notice that some monsters were staring at them oddly and choose not too attack.

"Tra la la we are off" the river person's annoying voice said once more as they started to leave the ruins after what felt like hours of walking. The goat monster always hated how the river person would say strange things like 'have we met before?' Or 'it's a beautiful day outside' both lines gets on his nerves, and almost made him thankful that the human seemed visibly irrateded at the river person and that might be why they had there head in the water the past minute.

Asriel quickly shifted his gaze to the human as they brought their head out of the water with a loud gasp for air. Asriel rolled his eyes at the human, what was the point in saving them if they were gonna try and drown them self after listening to the river guy?

"So um, how many bottle caps do I owe you for helping me?"

Wait what?

Asriel broke out of his thoughts when he was asked that and stared at the human with a questioning look on his face. The human had simply dug into their pocket for a brief moment and brought out...a bottle cap?

"Why would I need bottle caps for?" Asriel asked both out of curiosity and also finding the human rather stupid for thinking he wanted something as simple as bottle caps. The humans face twitches slightly as if they were suddenly realizing something terrible for them.

"...you don't use bottle caps as a currency down here do you?"

"...you use bottle caps as a currency?"

The human groaned and brought their face into their hands, not really paying attention to the water splashing onto their clothes a little. Asriel couldn't help but take great enjoyment that this human was apparently broke and that there life savings had no value down here.

The thought didn't last for too long as Asriel needed to think of how they were gonna convince his parent to let the human live, perhaps he could have the excuse that having a human could wield more information about the surface world and maybe after they take time to learn all they could they can simply steal the human's soul?

Asriel didn't get to focus on his idea for very long as the river boat finally stopped near the castle. Thankfully for him the human was actually feeling at least slightly better to walk on their own, though it was obvious they were trying not to appear weak though their attempts only made them look more and more pathetic to Asriel.

He brushed those thoughts aside as the guards opened the door to the castle, the human began to look around the place in awe upon entering it. The sight almost reminded Asriel of the time a few children were allowed into the castle for a tour the look of amazement and awe upon seeing the castle for the first time. The human eventually stopped looking to face two figures that Asriel knew only as mother and father, the queen Toriel and her husband King Asgore.

The king's cape moved at least slightly to reveal his father dangerous looking heavy armor. His white fur doing nothing to hide those dangerously long fangs from them, his horns normally pointing up seemed to appear only slightly curly as the thought of killing a human was so close to becoming a reality right now.

Queen Toriel on the other hand had a much simpler appearance, only wearing a black and red robe that is frayed in the bottom as if she had been in a fight before. Just like her husband and son she had yellow eyes and red iris's.

"My son tell me, why have you brought a human into our home?" Asgores voice oozed with anger and disappointment at Asriel for bringing them into there home.

"Father I know that we need something from the human, but we have been trapped down here for a long time; what little we know or remember from the surface might be irrelevant information-"

Suddenly Asgore had summoned a trident from a vortex of flames and it had launched directly towards the human. Asriel had not anticipated this in the slightest and was practically frozen at the actions of their father, the human on the other hand had reacted quickly and pushed Asriel out of the way in time before dodging the trident to the left, the fire just barely capable of leaving a small burn on their ear. Their free hand pulled out their 10mm pistol and aimed it at Asgore, ready to shoot to kill if they had too.

Nobody in the room dared try moving again, besides the human who licked two of his fingers and pressed down into the flame on their ear putting it out instantly. Asgore stared at the human who looked at Asgore with a bored yet analytical expression on their face; the king growled at the human who seemed rather too calm for this situation as if they had seen plenty of battles before.

Asgore once again summoned a trident and was about to begin an attack on the human, who still looked calm before letting out a exasperated sigh and glared at Asgore.

"Your son patched up my injuries ya know"

Whatever thoughts Asgore had were gone in a moment they said that, his stance faltered for a brief moment the human letting out a sigh of relief that Asgore was listening.

"If your son didn't patch up my wounds I probably would have bled to death, or gotten a fatal infection. In short terms your kid saved me" the human narrowed his eyes at Asgore show they were not afraid of the goat in the slightest "and from how things work in this fucked up world I am indebted to him...and unless you're an imbecile I think you know where I am going with this" the human finished and put their hands in their pockets shifting their eyes towards Asriel whom got up from the ground.

"It's true father, I thought we could use information for when we one day get out of here and what better source than from a human themselves?"

Asgore glared at the human for a few moments before shifting his cold gaze to Asriel, that look of pure calculation with zero regard to life was something Asgore had demonstrated throughout Asriel's childhood and he knew his father acted like this when deep in thought.

It just made him more intimidating in his honest opinion.

"Very well, human" said human tilted their head never stopping their glares at the king "you are now property of my son Asriel, what happens to you is his responsibility" Asgore turned towards Asriel before he had continued his small speech "do not forget the law of the land Asriel"

"I know, it's Kill or be Killed" Asgore nodded to his young son, proud that he has remembered that law; and took note of the thinking look on the human's face a question to be asked another time for sure.

Asriel picked himself up from the floor, not bothering to look at his father's eyes as he got up and walked out of the throne room. He swear he saw the human glare right into Asgores very soul for a moment, the anger in their eyes aimed directly at Asgore, it made him feel fortunate those eyes were not staring at him instead.

Asriel shook those thoughts out of his head, that feeling right now only made things more complicated than things needed to be; right now he was tired and he could figure everything out once they get some sleep.

The human on the other hand made a mental note that if any of these monsters were going to try and kill them; the king would be the first to die.

For now they wanted rest, and something in their gut told them they will need it.