Opening Remarks
Please bear with me just this once.

This is the first time I try to publish something on Undertale. I made this decision after witnessing the sheer liveliness this fandom was enjoying on this platform. Inspired by the thriving artistic community I found here, well... I decided to pitch in myself, for how worthless my contribution may be. I always strive for perfection, and this is another chance for me to improve. Hence, I hope this will lead to positive conversation with other artists and readers worldwide - and, hey, I'm always up for making new friends.

Recently, I have been immersing myself in the Undertale fandom. The story is absolutely fantastic, and its underlying themes very deep. My heartstrings have been plucked particularly by Sans; I find the smol skeleton incredibly relatable, and my soul just starts stirring whenever I think about him, his desperate situation, and the way in which he copes with it. It should not come as a surprise if this fanfiction sees him as one of its protagonists, then. So far, I've seen a lot stories about what might have happened the monsters left Mt. Ebbott, and an impressive amount of fantastic AUs that revisit Frisk's adventure in the underground. I have, however, seen little fanwork on what might have happened before Firsk's fall. Indeed, Undertale's history is complicated, and at times deliberately obscure; trying to make sense of it or speculate too much about it might seem daunting. Yet, I feel that it is especially because of its vagueness that more work could, and should!, be done on it. So here I am, and here is my take on that. I do not mean to propose this as the absolute truth or as what the great Toby Fox had in store for the story, nor do I wish to necessarily dissipate the mysticism surrounding the monsters' history. Rather, I'd like to see this story simply as one of the many, many, many possible timelines that Undertale might have followed. Maybe it will gain popularity and become an official AU (I doubt it, especially since I inserted a new character in the storyline) - Pastale? (that was lame). At any rate, I hope you will enjoy this story for what it is - a story, a fantastic, subtle distortion of reality.

To make this story work, I work with a number of basic assumptions which I think I should make clear from the outset in order to avoid inconsistencies in the future. I do realise that some of these might conflict with some information supplied by the Canon, but that is one of the reasons why this is, in fact, a fanfiction. I hope these will not impact your appreciation of the story too much, and that they will not prevent you from enjoying it nonetheless. I think I have managed to keep these alterations fairly contained, though, and I hope I have succeeded in staying in-character throughout. These assumptions are:

1) Monsters have much longer lifespans than humans.

2) Time flows differently in the underground (as if it were a different dimension (which it is)), with time flowing much more rapidly on the surface than in the underground. Consider also that the lack of sunlight to mark the flowing of time in days contributes to the distortion of time.

3) Looking at the pictures illustrating the war between monsters and humans, I drew the following conclusions:

A) The humans seem to wear armours and use old-fashioned swords and spears, so I have placed the beginning of this story in the Middle-Ages. Mages are also mentioned, which would work well with the middle-ages beliefs in sorcery and so on.

B) The silhouette of the big monster leading the monster army strikingly resembles Asgore, so I have made him to be king before, during, and after the war.

4) For the purpose of this story, I have made all the monsters we know of in UT witness the war as young kids. Hence, they have lived with humans, albeit for a relatively short time

Should I feel the need to clarify anything else in the future, I will do so in an opening or closing note. If at any point something is unclear to you, do not hesitate to drop an ask or send me a message! I'd be happy to clarify. Also, this story is being published on tumblr as well (just erase the spaces: cenereasquill. tumblr post/154780693137/singularity-11); I am working on thumbnails and stuff, just in case you will want to ask questions to the story's characters later on... I'm not an artist - sadly - but who am I to stifle their voices?

Finally, I would like to dedicate this story to a very good friend who, despite having his own problems and being overwhelmed by work, has patiently listened to all my endless rants about this story ever since it was just a tiny idea and has wholeheartedly supported me in writing it. This is for you.

I have kept you for far too long. Without further ado, I present you Singularity.

I hope you will enjoy your stay.

Thank you.
- Cenerea


Part I: Family Friends

Chapter I

When Sans thought about it now, the memories that invaded his imagination most vividly were the sting of cold air on his bones, the comforting weight of his brother holding onto the back of his jacket, and the immense emptiness of the immaculate cerulean sky above them. He knew those were dangerous memories to unearth, especially now that there was nothing to gaze up to any longer; but whenever his mind began dwelling on those precious moments, treading the thin line between dream and consciousness, he found himself taking a deep breath like he had done then — the grassy wetness of rice fields mingled with the coarseness of horse sweat and the lingering sweetness of flower blossoms to crawl out of his memory and tickle his nose.

It always took several seconds for his mind to adjust to what his body actually registered: the stagnant dampness of the cave's humidity, the freezing bite of snow, and the watery scent of soaked wood that the forest surrounding Snowdin emanated like a slowly decomposing corpse. His eyes would slowly open to welcome the familiar scenery consisting of rows upon rows of trees and the untraveled path dug out of the perpetual knee-high cloak of snow that covered the land. Allowing his body to slowly tear away from the memory of sunshine and fresh air, he first lowered his eyes to the wooden countertop he had dozed off upon, to then raise them to the sky out of an unconscious habit he suspected came from an old longing that still stubbornly lingered in the most forgotten corners of his mind – and was greeted by oppressively uniform darkness.

Sans sighed with experienced resignation, wondering why a small part of him was still deeply deluded by the sight; he relished, instead, in the pleasure of thoroughly stretching his bones after a nap. There was no time to dwell upon trivialities like those: Papyrus would soon be there to scold him for sleeping on the job. As per usual.

.*.*.*.

"How long 'till we get there, Sans?" Papyrus gently tugged at his brother's black jacket, looking up at the back of his skull before the rare sight of a water buffalo caught his eye and attention.

"I dunno, Paps," heaved Sans. His shoulders tiredly slouched forward and he let his head loll to the side in time with the horse's ambling gait as he abandoned his upright posture. He momentarily let go of the reins to rub his aching neck and shoulders, taking the opportunity to shoot a sullen glare at their father's back, who was leading their small company on his grey mare a couple of steps ahead. They had been traveling for weeks, and the elder skeleton brother was pretty sure they had gone through every single means of transport the age had to offer: they had started off on a carriage, switching to individual horses after about four days of travel; they hitched a ride on a traveling company's caravan, and walked the remaining distance to the mainland's coast when they could not find any animal-powered vehicle for hire; there they boarded a wooden ship, sailed for at least an entire week, landed somewhere else, and were back to horseback riding. This was the fifth day of travel in that new land, and, in all honesty, Sans had just about enough of that entire ordeal's absurdity. Who in their right mind would take two kids on a voyage across half the globe just to visit an old "family friend" he had not seen in ages? What an irresponsible parent theirs was.

Sans clicked his tongue in disapproval as he regained his former rigid posture. "Don't fall off the horse, Paps," he cautioned when he felt his younger brother's grip on him slacken as he turned around to stare at the placid animal bathing in the paddies' cloudy water. Papyrus flinched at the warning and instantly hugged him with all the strength his tiny body could muster, earning a couple of muffled cracks from the elder's spine, who could not suppress a pained hiss. Papyrus loosened his grip to whimper feebly a string of apologies which Sans nimbly cut off with a calm "It's alright, bro. I guess a hug is what I needed to crack on with this journey."

"It's not funny, Sans," complained Papyrus as his brother chuckled softly at his own pun. The elder could perfectly imagine him badly concealing a smile behind a determined pout, his bony arms crossed in front of his soft hide jacket. "Seriously now, don't fall off. Hold on to me gently," Sans repeated as soon as he felt the other slowly slide off the side of the saddle behind him. He shifted a couple of inches forward to let Papyrus have a little more space as the latter once again circled his waist in a lax embrace. Having made sure his brother was not in any impending danger of falling off the horse and breaking his neck in the process, Sans spent a moment just taking in the scenery, mainly to move his thoughts away from the black hole of frustration and tiredness they seemed to be constantly sucked into.

The place was indeed beautiful, with glistening rice fields stretching as far as the eye could see on both sides of the dusty path they trod upon and the hazy outline of a white mountain piercing the cloudless sky far off in the distance in front of them. Just beyond the fields prospered a vibrant forest, barely contained by a single line of drooping old shacks, most likely used as storage units for the rice trade's tools. He suppressed a shiver as the chilly air of mid-autumn kissed his cheekbones and wove its fingers between the folds of his clothes. Not a leaf stirred in that glassy-clear air – even the tiny soundless ripples of water striders seemed out of place; not a bird seemed to break its thin layer of frost with its bubbly chirping, if not for the occasional subdued sloshing of turbid water as it was disturbed by the slight movement of the figures submerged knee-deep in it, sharply bent over the younger rice sprouts. And in that surreal stillness, the cloudless, infinite sky weighed heavily on them like a lead cloak.

As they lazily rode along the only strip of dry land that cut through that emerald grassy sea like a ship's solidified wake, some of the women stood up from their toil to cast a glance at them, the strangers dressed in funny dark clothes. Some poised their wicker baskets on their hips and tipped their conical hats back to stare at them as they passed by; others stole furtive or strained glances as they tucked their skirts further up their knees to avoid getting the dirty fabric wet. While Papyrus returned their inquisitive looks with his own curious gaze, Sans did not fail to notice the hostile glares – brows knitting in deep, sun-charred scowls beneath a veil of shadow, and eyes narrowed to suspicious slits quietly burning holes in their backs even after they had passed them – or the wide-eyed gapes of pure, silent fear. He felt his own forehead crinkle with bitterness at the antagonism humans met them with regardless of geographical location or cultural heritage, and instinctively lowered the wide brim of his black hat over his face to hide it from view. "Papyrus," he whispered gravely, and his brother needed no further words to stop staring at the women and bury his face in Sans' back as his tiny fists balled up in his jacket. Sans awkwardly shifted a hand onto Papyrus' back to shield his sibling from any potential attack while his eyes impulsively fell onto their father: he rode on, heedless of the looks of hate and mute terror they were collecting with each step, his shoulders relaxed, his back straight, and the tail of his long black coat loosely bobbing in time with the horse's steady trot.

The tall grass rippled in a soft breeze; the gentle rustle of those emerald waves filled the eerie quiet surrounding them, an instant of movement in a bubble of stasis. Sans took a deep breath – and waded through.

.*.*.*.

Sans almost cried with joy when he heard his father pronounce the three magic words: "We have arrived." The last stretch of their journey had not been too disagreeable, with trees and bushes replacing humans and pleasantly filling up the space with their swishing branches and their countless shades of green, yellow, and brown. The soft scrunching of the horses' hooves on a golden carpet of fallen leaves as they ascended a slope even put him in a good mood, to the point that he had taken off his hat and had begun to exchange idle chit-chat with Papyrus regarding what sort of creatures would live in this kind of forest and whether they resembled the ones from home at all. Paps had begun talking about the surrounding flora and fauna to take his mind off the fear he must have felt as they crossed the rice paddies, no doubt; Sans obliged him with a couple of puns and made-up stories which, despite the initial irritated grumbling, earned a couple of giggles from the younger monster.

Thus distracted, the brothers barely noticed the tall wooden gate, once dyed a bright red, they passed under, and their cheerful voices gradually faded into curious silence as their horse came to a stop in a wide courtyard dominated by an imposing one-story building with a pointy tiled roof, a forked finial, jutting gutters, and what seemed to be gridded cream-coloured screen doors. Sans did not get a chance to examine that complicated piece of foreign architecture further as his father stepped into view, picked him up from underneath his arms and carefully lowered him to the ground, soon to be joined by a mildly excited Papyrus. Both brothers' legs were wobbly from almost an entire day spent on the saddle, and as they thoroughly stretched their tired bones their father knelt down on one knee to address them in his usual low, tender voice. "Good job making it through that long trip, boys!" The two kids stopped moving around to look up at him upon receiving a gentle caress on their skulls as prize for their bravery and endurance. "It must have been draining, and I do apologise for that. I'm sorry, Sans, Paps."

Sans felt a small smile stretch his invisible lips with a soft sigh: for how frustrated he could get at his father and his somewhat bizarre ideas, the man always knew how to ask for forgiveness. He was conscious of how weird or demanding his requests turned out to be, and was painfully aware of the strain that sometimes they placed on their small family of three – so he ended up apologising to his sons most of the time, and making up to them for the rest. He was a sweet man, their father; how could Sans be angry at him for more than an hour or so?

"This is my friend's home; I'm sure you will, but just remember to behave, ok? It's autumn now, but this is usually a very beautiful place." The adult skeleton raised his head to beckon his sons to look around, wordlessly inviting them to gaze at the weather-beaten but nonetheless masterfully carved lion-like statues guarding the entrance, at the beauty of the late-afternoon sunlight filtering through the foliage of two unbelievably tall camphor trees in thin golden festoons that shifted and swayed in the soft wind. Again there was silence – but a comforting feeling of peace came with it, as if the branches overhead were indeed hands protecting them from harm in an airy embrace, or sustaining that heavy sky in their place, catching any shard that might fall down before it could hit them. As Sans' eyes lingered on the white plaits woven around the trees' barks, his father began talking again, gently squeezing their shoulders where his hands had drifted as they took in their surroundings. "You will have a chance to rest and enjoy the natural beauty of this place, don't worry. Also, this friend of mine has a—"

"My friend!" An unfamiliar male voice came from behind them, cutting off the adult skeleton's sentence and making him turn around, while the two brothers leant to the side to peek from behind him. The kids' father instantly beamed at the sight of a fox monster dressed in a light brown tunic-like outfit approaching from the building's direction with one furry arm raised in greeting. "Sou!" the older skeleton replied, smoothly standing up and eagerly walking up to meet him. The two embraced and patted each other's back; when they separated, they still held their hands locked around the other's elbow.

"D'you think he's nice?" Papyrus whispered to Sans, leaning closer to him without taking his eyes off the stranger as he gleefully chatted with their father.

"Hmmm…" Sans did not really need time to think about it: the monster's warm smile, despite the sharp canines peeking out from under his muzzle's lips, as well as his clear golden eyes screamed friendliness – without mentioning the bushy tail wagging excitedly behind him, brushing away a stray golden leaf or two that had fallen on the flat stone tiles. "Yah, he seems cool. He's dad's buddy after all," the elder finally concluded with a light shrug.

"Think his fur is soft?" The young skeleton continued, eyeing fist the swishing tail and then the glossy mahogany fur covering his arms and what the fold of his tunic left exposed of his chest. Noticing the curious detail that the monster did not have paws but human-like hands which nonetheless retained animalistic claws and light pink pads, Sans simply replied: "Dunno bro; guess we could ask him if we can pet him later."

"That would be soooo cool!" exclaimed Papyrus, jumping up and down on the spot. His brother chuckled, pleased to see him so happy after the unpleasant experience of a few hours ago. "Well Paps, you sure do look bright-eyed and bushy-tailed about it."

Before the younger skeleton could protest at the bad pun, a definite shift in the tone of the adults' conversation made the two monster kids turn. The fox guy was sighing and shaking his head resignedly, his ears demurely going limp at the sides of his head. "I am really sorry I was not here to greet you the moment you arrived, but…" He sighed heavily as his shoulders slumped down. "I was looking for my child. I haven't seen her all day today, and I did tell her that we would be having visitors soon…" His head turned toward the forest encircling the courtyard, almost as if his daughter would magically run out of the woods at any moment.

His attention was immediately brought back to the skeleton when he placed a hand on his shoulder and squeezed it reassuringly. "No need to overthink it, Sou. We had only just arrived when you showed up." He smiled at his distressed friend, hoping he would stop blaming himself for a fault he did not have.

"I…" The fox monster stuttered, a look of grateful surprise relaxing his furrowed brow. "I don't know what to say. Thank you for understanding." He put his own padded hand on the skeleton's shoulder. "She's a total wildcard, you see. Can't bear to stay indoors for more than forty minutes at a time. No matter how many times I told her not to go into the forest unaccompanied, she just runs off with her satchel and a stick, screaming something about exploring and who knows what else," he concluded with a slightly exasperated, yet amused huff. "I'd bet my hide that she's in the forest right now." The other adult monster knitted his bony brow and hummed in response, surely in the attempt to think up the best words that might bring his friend comfort.

"Exploring?!" echoed Papyrus, catching both the fathers' attention. The tiny skeleton was holding his balled up fists in front of him, bobbing up and down on his heels out of sheer excitement. "That sounds like the coolest thingever!"

Their father's invisible eyebrows immediately went up as an idea zapped through his skull at the sight of his younger son's sparkling eyes. "Hey kids, d'you feel up for some exploring yourselves?" He asked with an eager smile. His fox friend gave him a confused look, to which the skeleton replied with a childlike glint in his fluorescent blue eye – "We'll help you look," he quickly explained before going back to his sons. "Stretch your legs and stuff in the meantime. Get your blood pumpin'."

"Oh, no, I could never ask you to do that, I can't possibly impose—"

"Sure, dad." Sans cut off the fox monster's flustered protests with his typical calm composure and a half-grin, much to the latter's thankful surprise and Papyrus' joy (which Sans, for once, did not wish to deflate with the pun he had wanted to reply with).

"Very well then!" The adult skeleton planted his feet on the ground, placed on hand on his hip and fully extended the other arm to heroically point at the forest to their left, a challenging smile animating his bony features. "You're officially on a mission, kids! Sou and I will hold fort here and look around the temple grounds just in case the little one is hereabouts. Time limit's sunset, boys! Make sure to come back before it's night, alright?"

"Cool," Sans replied. He began walking in the forest's direction, only slightly picking up the pace when Papyrus shot ahead with a euphoric war cry. "Keep an eye out for danger!" came their father's concerned voice from behind them, followed by a deep chuckle from the other adult monster. The elder brother raised a hand in reassurance; "Don't worry, I've got Paps' back."

"I see you haven't lost your knack for puns," commented in a low voice the fox monster, clearly amused. "And it seems like it carries on in the genes."

"Tibia honest, my son has already outdone me more than once before…" The skeleton's voice trailed off as the two adult monsters turned around to begin their own search. Sans snickered briefly, grateful that Papyrus was distracted by the hype of their new "mission" to hear their punny exchange.


God I'm bad at puns...
The reason why I have omitted a detailed description of the skelebros' father is because this is mainly a memory and some bits of it might be a bit... blurred. Rather than remembering faces, I thought actions, attitudes, and some particular details would instead stay a bit longer with someone.