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A Paradigm Shift: An Undertale AU SI

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Chapter One: The First Human, the Outworlder, the Doctor scattered across Space-Time, and the 7th SOUL


Chula Vista, California, 2018


You know for most people taking an hour long walk outside is usually pretty unexciting. Unfortunately for me that would not be the case for little old me. For those of you born in the wake of what happened next, I hope you sit tight and listen. For this is when everything in our worlds would start to change.




I was walking around Balboa Park and frowned as I passed by a small but happy family, it was nice to get out every once in a while but I didn’t feel in the mood to listen to other people’s conversations.


“Maybe I should put on some music or something.” I muttered as I grabbed my smart phone, an iPhone 7 with a battery case, and an additional portable solar panel I had bought for fun from somewhere. I put on some headphones and bobbed my head lightly to some music as I continued my walk. I took a look around and sighed as I realized just how big the park really was.


It makes sense I wouldn’t realize that since I’ve only been here like twice despite living here or near here for the past several years. I stopped at a large tree were there was a small event to let people pet reptiles.


If someone could see my eyes I’m sure they would have lit up in excitement. I hesitantly walked up to a girl who was two or three years older than me after putting my phone away. The tanned girl had wavy brown hair pulled up into a ponytail, and wore a red and black striped shirt with brown cargo shorts. She had a heart shaped face with almond shaped and almond colored eyes that twinkled with amusement. She was holding a rather large iguana like a giant scaly baby and beckoned me to get closer.


She smiled wide as I approached and slowly dropped the reptile into my waiting arms. That was about the time I noticed she was a foot taller than me and blinked in confusion. She looked puzzled at my reaction, but smirked as she realized why I was staring.  I focused my attention away from her and onto holding the big lizard and she quietly instructed me on the correct method. I wobbled a bit as I was put out off balance by the iguana’s wiggling. The girl giggled at my expression and I felt my ears heat up.


“Come on, don’t be shy he won’t bite.” The girl reassured me and gestured to her lizards head. I placed my left hand on his head and looked at her in question.


“He likes being pat on the head you know.” I nodded in understanding and started to pat the lizard’s head. The iguana rumbled in satisfaction and after a minute of that it started trying to crawl out of my arms. The girl swiftly grabbed the animal and I smiled nervously.


“Hah, it’s okay man! Greeny here doesn't really like being held for too long by strangers.” I nodded in response and the girl continued to talk with me. “But he does like you since he held out for at least twice as long.”


“Oh um thank you?” I took the complement with a small amount of confusion and the girl grinned once again. I paused as I felt my phone vibrate and pulled it out to look at the message.


Dad’s message read.


Ya te vamos a recoger. I texted back while the girl looked over in curiosity.


  1. I nodded as I read an extra message he sent afterwards and put the phone away after saying goodbye.


“Uh I sorta have to go now…” I fidgeted a bit under the girl’s gaze and she continued to look fairly amused.


“Oh ok it’s been nice meeting you…”


That’s new…


“Oh my name is Brandon.” The girl tilted her head and held up the hand that wasn’t supporting Greeny. She moved it up and down and raised an eyebrow at me.


“Oh right…” I started to shake her hand and the girl giggled as she noticed how stiff I was.


“My name’s Samantha.” She introduced herself and I started to smile back in response to her friendliness. Before we could continue anything else my phone vibrated with another text. I decided to end it right and there.


“It’s been nice meeting you.” I started to wave goodbye to the young women and she waved back with more energy and enthusiasm than myself.


“You too! If you ever wanna hang out I’m usually here at noon on the weekend.” I nearly stumbled as I started to walk away and I nodded nervously in reply. She smiled widely one more time and I gave her a final wave before picking up the pace.


I took a look around to orient myself and walked in the direction of the parking lot my dad had left me off on. I would have driven myself if I had anything more than a permit to my name, but what can you do. I started to hum out of boredom as I continued at a leisurely half jog.


It was a quiet rendition of His Theme, that had been stuck in my head along with all the other Undertale songs after I had finished the Pacifist route. Honestly I haven’t had it for long and I’ve practically fallen in love with its story and characters. Some of the fandom is a bit weird and occasionally creepy. But the the more normal members give me a sense of community that makes me feel nicer and warmer than usual.


As I reached the parking lot I started to slow down and finally paused and took in my surroundings. From above I could a vast dark red cloud that seemed to blot out the sun as well as the blue sky. I narrowed my eyes as I saw very odd red shapes come down like sheets of rain and ice.


They looked… like nines…?


A sudden almost insane realization came to me but there was no more time to voice them as the objects suddenly hit their marks. I collapsed to the ground and started to head a near constant roar of screaming as well as an odd crumbling sound and then—






W-where am I?


What is this place?


I only remember nines…?




Now I…




Reloading Dimension1.01.rom


Reloading Undertale.rom




Transferring Undertale.rom and Dimension1.01.rom to [Redacted].rom


What is this?!


Resetting FRISKchr


Resetting ChARAchr


Restore GASTERchr


Remove Universe Size limit


Remove True Reset




What the hell is going on?!


Altering Physical Law parameters


Adding anti-virus protection


This is the oddest dream I’ve ever had in my entire damn life, and that includes the time I dreamed I was a Reaper from mass effect, and got melted by lava in Star Wars.








I have a bad feeling about this…


Add Server Connectivity?




Reset BRANDONchr?




That sounds really bad, and the worst part is I’m only hearing some of the commands being made. Around the strange void I could suddenly sense a gooey and inky blackness surround me as the deep and reverberating voice continued to yell out it’s strange commands.


Continuing Data transference…


BRANDONchr successfully transferred


GASTERchr successfully transferred


CHARAchr successfully transferred


I felt an agonizing pain throughout my body, and the shadowy goop began to swell up, pushing past my knee height. I began to sink into the goop, and distantly heard other screams beside me. I was choking on that strange fluid and cried out.


“Please somebody, anybody HELP ME!”


But nobody came.



I opened my eyes as I heard a loud and irritating whistling noise rushing past my ears. Within a couple of seconds I instantly regretted my poor choice. Because down below was a vast green land a few miles below me.


“W-what!” I yelled out in frightened confusion. There was a large mountain but I ignored that as I fell to my doom.


“NOOOOOO!” I screamed endlessly as I fell for the next two minutes. I curled up in ball, and waited for the end to come. Of course as I fell I realized that I was over a small lake and I had a small chance to survive if I hit the water. But as I turned my gaze to the ground that hope was dashed as I noticed that my trajectory had already shifted away toward a yellow patch. As another half minute passed, despite my panic I noticed a massive field of golden flowers near a large green mountain that seemed oddly familiar.


My eyes narrowed as I heard what sounded like girlish giggling and unintelligible muttering. I looked around in panic but found nothing that would tell me where the strange sounds were coming from.


Wait… I’m STILL FALLING! The ground began to rapidly approach me and I loosened up and my limbs began to flail uncontrollably. I closed my eyes and braced myself for the end.


“AHHHH!!” I screamed out and waited for the splat of my body being strewn across the flowery plain.





What was that thunking sound? I had closed my eyes momentarily since I… You know was falling to my death and all. I opened my eyes and found myself floating one foot above the ground.




Which was when my brief defiance of gravity ended and I fell flat on my face. I lifted myself up with shaky arms and legs and stood up high as I looked around in confusion. I looked up, and off in the distance I could see strange white holes at least a few miles out from where I was. There was something that felt off about the air and I almost felt light headed just being here.


I felt the brief sensation of pressure behind my eyes and was moments away from bursting into tears.


“I… I’m alive.” I sighed in disbelief and relief and simply lay on the ground to rest from my ordeal.


‘This is very, very interesting.’ I was startled and fell back to the floor as on older and gentlemanly voice broke


‘S-shut u—‘ A much younger and feminine voice replied but it sounded somewhat distorted.


‘What do you two think?’ The man continued as if the child hadn’t spoken at all, and my eyebrows furrowed in open confusion. I had enough of this and decided to ask what the hell was going on.


‘Who’s there?’ I asked hesitantly and I heard the quiet grumbling of the child and the muttering of the man. I waited awkwardly for them to speak and I hoped I hadn’t just gone mad or gone on a drug trip.


‘Greetings I am Chara.’ I raised my eyebrows in shock at the familiar name. I looked around to see if I wasn’t somehow being pranked, but found nothing that would support my theory around here.


‘You may call me W.D Gaster.’


The fuck is going on!?




That voice from before, they mentioned both of their names as well as all those strange commands.


‘How rude.’ I huffed at the scientists indignity and found a clear pool of water in a patch of open grass. I took a look of myself for posterity, in case I didn’t see a mirror in the near future, I’ve also gracefully decided to describe my appearance for whoever is watching me. Clearly this is an Isekei fic designed to mess with me, for some interdimensional writers sick enjoyment, but let’s ignore that for now and get back to description.


I had an oval shaped head with lightly defined cheekbones, and I was rubbing my light black beard, with a few stray yellowish hairs. I had straight black hair swept aside to the right and it was of moderate length. I was wearing a slightly stained plain green t shirt with my loose dark blue jeans and dirty black Nike’s sneakers and white socks. I saw a brief distortion in the reflection and took a closer view.


I almost screamed when I saw two other people in the pool but covered my mouth just in time. On my right there was a confused red eyed and brown haired girl with peachy skin and rosy skin, and wearing a lime and cream colored striped shirt with brown pants and shoes. Her hair was the style as in the game, and her face was fortunately more expressive. She looked to be around 12 to 13 year old. Her round face was currently twisted into a look of confusion and fear.


On my left however… was something wholly different from the young girl who to my own consternation was only about 4 inches shorter than I was. The being seemed to be a skeleton of frankly immense height, maybe six foot eight. He wore a suit of some sort over a grey sweater and had a large scar that just touched the top of his right eye. He seemed oddly giddy, and somehow managed to smile without having actual lips. I turned around and cursed under my breath when the two beings were still there, if a little transparent. Chara wrapped her arms around herself in clear to see anxiety and Gaster did some odd hand motions I didn’t understand.


“Well this is perfectly normal, yep. There’s no issue with seeing ghosts or anything.” I heard the girl scoff and I began to walk toward that mountain.


‘What are you doing?’ She asked me as she and Gaster were dragged along on my hasty jog. Out in the distance I could see what looked like the ruins of a modern city, and the girl looked almost fearful at that damage. It made me stop as I saw from the distance what looked like deep furrows burrowed into the city’s foundations. It was like something had drilled through the city using plasma. I turned toward the girl and her eyes suddenly widened.


‘DUCK!’ I obeyed her with great confusion and threw myself onto the ground and paled as the sound of a bullet whizzing by my head could be heard.  I scrambled into a separate field of tall sunflowers and kept my head down. The girl screamed shrilly when a bullet phased through her, but sighed in relief when she felt no pain. I continued to crawl under the flowers as fast as I could.


“What do you see?’ I asked my two allies of convenience and I heard the doctor murmur in thought. The human stuck close to me, and I saw her shake in fear.

I waited for at least one of them to answer me, and I heard Gaster cough.


‘There are a sizable number of heavily armed humans 170 meters to your left, they are congregating around several armored wheeled vehicles. They appear to be screaming at a short human with a rifle of some design. Very interesting to see human weaponry in use.’ He replied coldly.


‘They’re trying to kill me you know that right?!’ I internally screamed at the doctor and I felt him shrug. I frowned and noticed that my phone was somehow in my pocket, but decided not to question it for now along with everything else. I heard screams and gunfire and decided I should really keep running.


I felt the earth shake as what sounded like missiles and artillery struck around the field. I ran toward toward the mountain in desperation, and almost fell to the ground as another quake was triggered.


‘Keep running you idiot!’ Chara screamed in desperation. I picked up the pace and the mountain slowly drew closer as I ran for my life. The light faded as I entered a small forest near the base of the Rainier like mountain. The gunfire and explosions started to grow quieter as I fled deeper into the forest and I collapsed onto the ground as my long hike finally caught up with me. I gripped my chest as I breathed in and out harshly.


“I…I’m alive.” I wheezed out as I rested against the side of a tree. I rubbed the sweat that had formed on my forehead and then wrapped my arms around my legs. The strange duo that had latched onto me remained quiet and left me to my thoughts.


Okay let’s think more on what’s going on here, and what I can do about it. Somehow I had been teleported into another reality and or planet and was potentially trillions of miles from home. Wherever I was seemed to be pretty post apocalyptic, with all the rogue psychos around. I need to get off of this planet right away and if I can’t do that, somewhere that could act as a fortress until everything calms down. Okay then that’s all of I’ve got right now.


Oh wait there’s also the fact it seems like my entire universe seems to have been exploded into a million little pieces and scattered across an unknown universe with unknown threats.



“I’m going to fucking die aren’t I?” I asked myself miserably. I flinched as I felt Chara’s tiny hands pass through my head. I glared at her and she glared back, her red eyes lighting up with anger.


‘Don’t be a baby, and keep heading up to Mt. Ebbot, I know a place you can be safe.’ She chided informatively. I huffed and stood back up on my feet. As I walked the path slowly grew steeper, and I decided to have a conversation with the two. There was really no harm, since this was either real or I had gone insane so whatever.


“Right so anything you can tell me about yourselves?” I asked the both of them. Chara looked surprised while Gaster looked almost delighted to speak with another being. Chara grimaced and I wondered why she looked so irritated.


‘Don’t you already know everything about us with that game?’ I almost tripped when she acidicly replied. Uh so I guess she somehow got the knowledge from my head then?


‘When we uh showed up Gaster received some of your memories of the game and told me about them” She answered quietly. I raised an eyebrow as I continued to trudge through the empty forest. So the doctor got my memory while Chara didn’t?


“It doesn’t mean I know everything about you, you know that right?” She muttered under her breath in slight embarrassment, and I heard the doctor quietly chuckle. Chara looked uncomfortable and sighed and I looked at her with some concern.


‘What’s wrong?’ I asked and I heard her mutter ‘Like you care.’ I waited patiently and she covered her face with her hand.


‘It feels like I’m supposed to be with someone else, and that you’re the only one who can take me to that someone.” Chara sounded confused and seemed to be pretty close to a nervous breakdown.


‘I’m sure everything will be fine.’ I reassured her, but based on the look on her face she clearly didn’t believe anything I said.


‘Come on I’m determined to see this through.’ Gaster looked curious and I took a step back as his hand began to rummage around my body. He couldn’t actually touch me but it was still really odd.


‘Clearly not a Determination SOUL, but perhaps one of Perseverance?’ He said as he continued to analyze me. I decided to back away from the crazy doctor and—




And then proceeded to trip over something behind me. I rubbed my head as the pain pulsed through it and groaned. I felt whatever I tripped on squeak and I crawled away in shock. I swear I saw Chara’s rosy cheeks grow darker, as the mysterious object came into view from a pile of leaves they had fallen into.


A girl of similar height and age to Chara emerged from the pile, gripping her head in pain. She seemed to be of Filipino origin mixed with something else, her roundish face twisted in an expression of fear. She wore a striped purple and blue shirt with blue pants and brown shoes. The girl had medium length straight brown hair, and although her eyes were half lidded, I could tell they were an odd if pretty lavender color.


“L-leave me alone!” She begged and I looked at her in confusion. I noticed that Chara had drawn closer to the girl, though she didn’t seem to actually notice this. The doctor retreated behind me and looked at the girl with a cold scientific curiosity.


Maybe we need something to break the ice and calm the girl down a bit. Okay what to say, what to say. Wait a minute I’ve got it, I know exactly what to say.


“Don’t you mean Leaf me alone?” I asked her and she gave me a look of confusion as she processed the question. Her scared face turned into a blank expression once she got what I meant.


‘Really, that’s what you go with?!’ Chara groaned at the pun, but froze as the girl giggled at the joke. I picked myself up off the floor and offered the girl my hand. Surprisingly she took it and I lifted her back up on her feet pretty easily. She brushed herself off, and pulled a few stray leaves out of her hair. The girl seemed much less wary of me, but I frowned when she turned toward Chara and shrieked. Chara jumped back, and flailed around as she started to float.


“AHHH!” Both girlishly screamed and my eyes widened when I realized that the girl could see Chara, and based on how she glared at something behind me could see Gaster too.


‘You can see me?’ She asked hopefully and the girl nodded. That was when I noticed a very thin red string that seemed to connect the two, as well as a purple string that connected Gaster and I.


That was also when I noticed a strange bird like creature that was closely following Frisk. It was maybe about half my height and had very long tail feathers extending out from a tail. It’s full coat of feathers were a mottled mix of brown, white and black. What I thought were wings started as a dark brown, to a cream color, darkened to dark brown and ended in cream feather tips. The wings were in fact just heavily feather arms, three fingers with sharp claws curled  together.


The animals belly, legs, torso and face were similarly cream. The tips of its mouth were lined in smooth black scales that made its snout look like a beak, but a small hiss revealed a great number of teeth. It’s legs were long and feathered and ended in three clawed toes with a single sickle claw on its second toe. It’s shining golden eyes glared back at me in a slightly aggressive stance.


Is-is that a…


The animals aggression was swiftly calmed by the girl, who began to stroke it’s back gently and I heard her quietly coo to it. The dromaeosaur relaxed and bounced from one leg to the other as it looked at me with a restrained curiosity. Frisk smiled at her pet’s(?) behavior and turned back to me but as her mouth opened to speak to me, a large and haunting booming sound stopped us. Frisk started to shake and her small bird like companion shrieked in alarm, it’s wing-arms flapping in fear.


I turned around and only looked at confusion at the appearance of what looked like a feathery trunk. That’s a pretty weird tree isn’t it? Especially with the three massive toes on its feet…


Oh crap…


I started to look up and paled as I made eye contact with massive searing orange orbs on a lightly feathered and boxy skull. It was tall, it’s head about 20 feet above the ground, and when it rumbled I felt my bones and organs shift around under the sound waves. I could barely see a dense coating of dark brownish black down that covered its back, head and neck, that then transitioned to a white coat that acted as a border between its primitive feathers and its smooth dark black scales. Most of its underside remained scaled and it was frankly beautiful, but I was more worried about the dozens of very sharp teeth in its open jaws.


“We should go.” I said with supreme calm and slowly grabbed the nearly comatose girl and began to walk away. The maniraptoran followed us with similar quietness, and we flinched as a branch was broken by Frisk’s footsteps. The Tyrannosaurus slowly and quietly tilted its head in our direction.


RUN!’ Gaster screamed and the super predator boomed. The trees started to tremble and despite the massive lurch in our stomachs we began to run. We twisted a path through the dense foliage, and I felt shivers run through my spine as infrasound vibrated the air. The Dromaeosaurus like being pulled ahead us but it’s odd chirps and hisses gave us something to follow, and it seemed to slow down whenever we got caught in a vine or bush.


The large dinosaur chasing us was clearly abnormal since it seemed to be continuing to follow us based on the very subtle vibrations of its footsteps. Since this isn’t Jurassic Park it should be ignoring something of our size, unless it has eggs nearby. But since it’s summer there shouldn’t be any, there could be some chicks nearby though. My thoughts were interrupted however when I felt my left foot trip on something sending us tumbling onto the ground. Our animal companion fidgeted nervously but stood its ground as the Tyrannosaurus knocked a tree over and walked out into the small clearing we were in.


I froze when I took a closer look at the citrine eyes of the massive theropod. It’s eyes blazed with a raw hatred tempered by a startling intelligence that juxtaposed it’s primitive bruteness and bulk.


We… were going to die here weren’t we? I started to hyperventilate as the beast drew ever closer, until its massive foot rested in the slightly damp soil one foot in front of me.


I…can’t die, I don’t want to die like this. But the… perhaps animal isn’t the best word for something this intelligent. The being stood perfectly still and I waited for it to just do something. It stared at something behind us and backed away and I almost breathed a sigh of relief. I felt a tug on my shirt however and a terrified Frisk pointed shakingly at the beings eyes and I shivered again at the sheer loathing within it, no her eyes. Something huge rushed past us and I pushed Frisk out the way of a thrown boulder.


“You missed!” For whatever reason I stupidly taunted the Tyrannosaurus and I gave it a look of confusion as it seemed to look smug.




Our little group flinched as the ground began to shift, and I would have facepalmed as I realized we were on the edge of a certain cave entrance destabilized by the literal ton boulder. We began to slide toward the entrance, and the two of us that were corporeal tried to scramble out of the collapsing area. I heard another crack and the entire section of ground broke off. The two of us were quickly pulled into the cave with no hope of escape. As the two of us fell into the mythical Underground of this humanities legends, I thought to myself.


Well Shit.



“well shit.”


Deep underground a certain pun loving skeleton fell off his bed in a heap as if waking up from a horrible nightmare. He grumbled on the dirty ground of his room and lazily picked himself up. He took a glance at his self sustaining trash tornado and yawned. A bright blue glow from his left lit up the room and was quickly shut with a growl.


“heh, guess the little duo really did a number of me didn’t they?”


sans took another look around his bed room and sighed. He stiffened up and suddenly vanished from his room.


Something had clearly changed. A cold sweat broke out on sans skeletal forehead as he grabbed a computer on his lab. Strange and previously unreadable code became perfectly legible and his eyes would have widened in shock if he could.


‘this shouldn’t be possible!’ sans thought in a strange mix between fear and relief as the computer suddenly spit out a tremendous amount of data.


“it’s only the last 100 resets that i’ve been able to remember even with a “true” reset. I couldn’t find a way to record the Anomaly before but…” sans trailed off as he read the data given to him by the blocky computational device. His breath hitched in horror as one particular statistic was read out to him.


“4,576,378 Resets huh…” The nihilistic monster bitterly chuckled as he grabbed a picture and stared at it with longing. In it stood a a young human girl widely smiling along with several monsters, sans, and his younger brother. He put the picture back down and it settled on the table with a soft “clunk” sound. He read out some more information and his breath hitched even more.


“this could be the last reset now, especially since the duo aren’t under the influence of that thing anymore.” sans muttered under his breath and his left eye glowed as his Determination and Hope rose for the first time in a very long time.

“they don’t have much if any memories of what they did before, and with that poor sap along for the ride, things are going to change.” A light popping sound could be heard as Sans took a shortcut back to his room


“i can’t afford to not care anymore.”