AN: Welcome to my Undertale AU fic! As alluded to in the summary, this is an AU where the monsters are angels, though they do retain their beloved original designs, just with the addition of some kick-ass wings, lol.

I'm planning nine chapters, one for each trial, plus an interlude and epilogue. They'll be quite long, and I'll update as I'm able. :)

Follow me on my side tumblr jolieburnsinfandomhell for updates, sneak peeks, and fanart!

Chapter One

First Trial / A New Friend

Sans' breath clouded the air before him as he sighed and resettled himself more comfortably against the door at his back. It was cold that day, and though lacking as he was in the usual physicalities that most possessed temperatures at either extreme didn't normally bother him, even he had to admit this was a bit much for comfort. He might not be a candidate for frostbite, but it was the sort of deep, penetrating cold that made even his bones ache.

"ah, got it," he said, grinning to himself as he pulled his shabby, threadbare blue jacket more tightly around him. "what did the ghost give his date to the prom?"

A moment of silence, and then, from the other side of the door a distinctly feminine voice asked, "What?"

"a boo- tineer."

The chuckle that came from behind him wasn't quite as energetic as he was accustomed to, making Sans' smile drop. Two hundred years they'd been trapped in the underground and for at least one hundred and fifty of them, he and his fellow seraphim, Toriel, had been meeting to exchange bad jokes in a sad sort of last ditch effort to keep their spirits up.

Toriel had remained in the ruins after everyone else had migrated deeper into the Underground after the fall, and locked the doors soundly behind them. He hadn't laid eyes on her since that day, though he had come to check on her regularly since then. It hadn't taken long for their little joking habit to start up as a way to pass the idle hours.

"c'mon, tori, you gotta work with me here," Sans said, his attempt at a chuckle coming out as a tired huff when he dropped his head back against the door. "i'm running dry on material here and you've barely managed a word. what's got your goat?" he asked in one last attempt to lighten the mood.

She didn't reply immediately, and the skeleton let his gaze drift upward to watch the small flakes of snow drift silently to the ground around him while he waited. All these years and he'd yet to figure out how it managed to snow in the underground; an eternal puzzle that would likely confound him until judgement day finally came around, assuming it didn't pass them by entirely in their exile. Maybe it had already happened and they hadn't even noticed here in the little purgatory Sans himself had long since considered a private hell.

Finally Toriel spoke again, though her question wasn't one he had expected. "How is your wing, Sans?"

The seraphim's shoulders tensed reflexively at her words, and for a moment Sans could only sit in silence as the snow fell around him with tiny, crystalline clinks that felt loud as thunder. Eventually, he started to breathe again, and gave his shoulders a practiced roll that unveiled the vast, pale wings that marked him for the angel he was.

It was a striking sight to behold. The wing that sprouted from his right shoulder was broad and strong, longer than his four foot nine inches in height by many times over. Its feathers were a soft, luminous white that made even the virgin snow at his feet appear gray by comparison. The left, though just as long, was a charred ruin made only more tragic by the untouched beauty of its counterpart. What feathers remained along its length were marred by a black ash that could not be washed away. Only those nearest his spine retained their former healthy luster, untouched by the misfortune that had mutilated the rest.

Sans stretched both wings to their full extent, stirring eddies of snow around him with every careful movement. He bit back a grunt of discomfort when pain inevitably lanced through his ravaged limb, compelling him to relax them once more.

"same as ever," he told Toriel, the white lights that served as his eyes dimming some as he spoke. He rolled his shoulders again, and his wings vanished from sight, tucked away where the ever present pain was less immediate. It never truly faded, though, not once in two-hundred years. "still looks like a reject basket of fried chicken wings," he joked half-heartedly, though he knew Toriel hated when he did so about his own handicap.

To his surprise, his fellow seraphim didn't chastise him as he was accustomed. Instead, in a soft, solemn voice he was only barely able to make out through the door, Toriel asked, "Does it still hurt?"

"nah," he answered without hesitation as he pulled his hood up over his bare head to fend off the chill and the thickening snowfall that was beginning to accumulate on his person. The flakes seemed to be growing in size by the minute. "barely even notice anymore," Sans added.

"Liar," she murmured, and Sans couldn't bring himself to contradict her, knowing it would likely only make her angry. When Toriel became angry, she often wouldn't return for their little get togethers for days at a time. Once, she'd gone two whole weeks without so much as a word to him, no matter how many jokes he'd made while sitting in front of the door to the ruins.

"well, at least my pants aren't on fire," the skeleton remarked.

"I wouldn't know," Toriel mused.

Sans turned a little where he sat so he was looking at the door now. It was huge, nearly thirty feet tall, at least fifteen across, and crafted of solid stone. Every detail of its arched frame was familiar to the skeleton thanks to many an hour spent examining it while speaking with his friend voluntarily imprisoned on the other side. "you could," he said, voice low, almost pleading. Her self-imposed exile was a long standing argument between them that they likely wouldn't agree on until the facade of the door itself crumbled under the weight of ages, leaving nothing to bar their passing but empty words. "-if you'd just open the door. you don't have to come out, i could come in, and-"

" No, " Toriel said, normally soft, pleasant voice harsh with emotion. "I will never willingly open these doors again. And neither will anyone else, not so long as I breathe."

The implications of the seraphim's promise were not lost on Sans. "but, if a human-" he began, fully turned to face the door now as he sat on his knees in the snow.

"I said never, " Toriel repeated, voice shooting up an octave. Before her friend could try to talk her down, she asked, "What happened to the last human that won their way through my trial, Sans?"

The skeleton hesitated, one hand instinctively held out towards the door, as though he might reach her despite its presence between them.

"Sans?" she asked sharply, though he had known her too long not to recognize the hint of tears behind her words.

The seraphim sighed and slumped forward until his head rested against the smooth, chill surface of the door, hand dropping into his lap. "I never saw them," he said, dodging her question. At her stoney silence, though, he admitted, "they never made it past the third trial."

"How many have made it to your trial?"

Sans grit his teeth, eyes slipping shut as he heaved a sigh of resignation. He knew there was no way he could avoid the conversation without getting up and leaving, and that wasn't something he was willing to do yet.

"one," he answered eventually, voice low and reluctant at the admission.

"And did they win their way past?" Toriel asked, though Sans knew for a fact that she was already well aware of the answer. She had been the only one he had told the whole wretched story to, after all. It had been over a century since that day, but he still recalled every detail, and he had no doubt that she did as well.

"no," he ground out. "i brought her heart to Asgore myself."

Bitter silence fell between them, and Sans might have gotten up and left had he not found himself rocked by the memory of the last time he had been forced to pass judgement on a mortal soul. No doubt the human woman he had cut down had once been a kind creature, but the pressures of the trials she'd been forced into against her will had twisted her into something looking only to survive. That did not absolve her of her sins, though, so he had carried out his god-given duty...

Behind the door, Toriel sighed, and while her voice sounded more controlled when she spoke again, it was clear she would not be swayed on the subject. "All those humans, and its never helped us, has it? Never brought us closer to freedom. Asgore has doomed us all, but it is not our place to punish the humans that fall into the Underground for his crimes." The seraphim took a breath before continuing. "I can't take anymore, Sans. I'll send no more humans to be slaughtered."

They fell quiet again, but the skeleton could think of nothing to say, knowing full well that Toriel was never one to change her mind easily. It'd take someone greater than himself to do so.

So, instead, he asked, "hey Tori?"

"Hmm?"

"why was three afraid of two?"

A beat of thoughtful silence and then, "I don't know. Why?"

"because he killed every one!"

More silence.

"Too soon, Sans."

"Can't you see that I'm doing this for your own good?" Toriel begged as she watched the child before her hastily dodge a gout of flame that consumed the stick she had taken to carrying around everywhere. The little girl yelped and dropped its smoking remains, making the seraphim's heart drop into her stomach as she fought the urge to rush to her aid. "Please, just go back upstairs! You can be happy here, I promise. I'll take care of you, I'll teach you how to make cinnamon butterscotch pie...you can have a life here!"

"Please, please stop!" the child cried, shying away from a fireball that veered too near. Instinctively, Toriel guided it away from her, the seraphim's broad, cream colored wings fanning the air in her distress. "I don't want to fight, but I can't stay. This isn't my home!" the little girl insisted, tears spilling down her soot-smudged face.

The sight of the child's tears broke Toriel's heart, and she knew she could not possibly win. Not against this human, not at the cost she would have to pay to keep her there. "Do you...do you really hate me so much, Frisk?" the seraphim asked in a small voice as she let her fire die out around them. "Would staying here be so awful? Awful enough for you to risk facing all seven trials?"

Frisk lowered her hands, hesitating until she realized the fires had well and truly faded. Then, she stepped forward, hands outstretched to Toriel. "I don't hate you, Toriel," the little girl insisted tearfully. "You're so nice, and your cinnamon butterscotch pie is super good… But I made my grandma a promise," she said and lifted one hand to the crown of golden flowers that rested on her head. "And I...I have to go home."

Tears spilled down Toriel's pale cheeks as she watched the child step forward, hands reaching for her, just as her son had done before the fall…

"I know. Oh I know, you dear, sweet child," the seraphim said and wiped away her tears before taking Frisk's hand in her own and pulling her into a tight embrace. Toriel had to kneel so the girl could bury her face in her shoulder, but she paid the dirt and soot that stained the knees of her dress no mind. The angel wrapped her wings around them, cocooning them in their warm softness for a long minute until they had both managed to stop crying.

Ever prepared, Toriel fetched out a clean handkerchief and carefully dabbed at Frisk's face. "Keep it," she told the girl when she was done, and pressed the square of white linen into her small hand. "You never know when you'll need a hankie."

Frisk did as she was bid and pocketed the handkerchief with one hand while still maintaining a hold on Toriel's with the other. "What do I do now?" she asked, brow furrowed under the fall of her brown hair.

"Follow the path out of the Ruins and you'll find the second trial before you reach Snowdin," Toriel said as she got back to her feet and furled her wings. She was quiet a moment before saying, "Oh Frisk… please be careful. As soon as you pass through that door, you cannot return, do you understand?"

Worry was clear on the little girl's face as she lifted it. "What?" she asked. "Will I ever see you again?"

Toriel gave the girl's cheek an affectionate pat. "I do not know, my child," she murmured, tears threatening once more. "I pray to the creator that we will." The seraphim smiled, then, and after pressing a kiss to the top of Frisk's head, she said, "If you are very good, and very brave, then I have faith that we will."

Frisk nodded, a little hesitant, but rallying quickly. She released Toriel's hand, but before she'd made so much as a step, the seraphim stopped her.

"Wait! One more thing," the angel said, then swept one of her wings forward and plucked a single feather from among the many. "Take this. Should you meet someone named Sans in your travels… give him that from me, okay?" Toriel explained patiently as she pressed the feather into the girl's upheld palm.

Frisk took it, and ran her fingers over its silken length. It was quite small compared to the seraphim's great pinions (which were longer than the girl was tall), though still nearly as long as her hand. "Okay," she agreed with a nod, then tucked it carefully into her sweater's pocket where she was sure it would not slip out.

"Good girl," Toriel said, then unlocked the great gate that separated the Ruins from the rest of the Underground. Despite their obvious weight, and the startling shriek of rusted hinges that had gone long unused, the seraphim pushed open the doors open with ease, then stood aside to let Frisk pass.

As she did, the little girl threw her arms around Toriel's waist one last time, and the seraphim gave her back a reassuring pat. "I'll miss you, Toriel," the human mumbled into her skirt.

"I'll miss you too, dear one," Toriel said as she returned the embrace, then let the girl step through the door and out into the snow. "Be safe, Frisk," she implored the child, then quickly closed the door behind her before she caved to her impulses and snatched the human back inside where she would be safe.

The dull boom of the gateway to the Ruins closing behind her rang with such finality that a shiver unrelated to the chill in the air rippled up Frisk's spine. She turned to face the door briefly, brow furrowed unhappily as she said, "Bye, Toriel."

The sound of someone coming towards him on the path to the ruins brought Sans up short. He could count on one hand the number of times he had met someone on this particular stretch of woods in the last hundred years. The trail wound through the darkest depths of Snowdin forest, and had little to offer a casual visitor. Just snow, trees, and more snow; all of which one could find in abundance much closer to the relative comfort of Snowdin village.

Curious, Sans stepped off the little traveled path and ducked behind the nearest tree. There was little he could do about the trail of footprints he'd left in the fresh inch of snow on the path, but he would see whoever was approaching from the Ruins long before they noticed that little detail.

Whoever it was, they took their time, and Sans had very nearly given up on waiting for them to come around the bend in the path when they finally appeared. An inch or two shorter than Sans himself, the stranger was not tall. They were clad in a bulky periwinkle and pink sweater with fitted pants, and a pair of sturdy looking boots, none of which seemed quite warm enough for the weather. The crown of golden flowers the newcomer wore on their head was a splash of vibrant color that stood out in stark contrast against the pristine snow and dark, bare tree trunks that surrounded them. That unique, familiar shade of gold held Sans' attention so completely that the wearer's species went completely unnoticed until they had passed his hiding spot.

A human. A human had left the ruins.

The shock of this revelation shook Sans to the core, and locked him in place until the human had disappeared around the next bend in the path. A hundred questions roared through the seraphim's mind as he stood frozen, though a few cried out more loudly than the rest.

How? Why now? What had happened to Toriel?

The final question snapped Sans from his trance and sent him scrambling back onto the path to sprint after the human. Even wearing heavy boots as he was, the seraphim moved silently through the snow and quickly caught up to his prey, who was still walking slowly down the center of the path.

All the stealth in the world couldn't save him from his own carelessness, though, and when he stepped on a heavy branch buried under the snow, the sound of its breaking rang out through the silent forest like a gunshot. Swearing silently, Sans dove off the path just as the human spun to look at him, expression frightened. When they found nothing but the broken branch in their wake, they started walking again, though not much faster than before, making the skeleton wonder. For all they had appeared panicked at the sudden crash, he would have expected the human to break into a run.

Realizing he was being ridiculous (really, what was he even hiding from?), Sans climbed up onto the path once more and started after the human at a more sedate pace. When he caught up to them next, they were at the bridge across the gorge, appearing hesitant to step out onto it. They heard him approach much sooner than he would have guessed, judging by the tension that seized their narrow shoulders.

Unable to resist, Sans slipped his hand into his pocket, and spoke, breaking the silence that hung heavy in the air between them. "human." They didn't turn immediately, but he could see their shoulders go from tense to shaking as he continued to approach. "don't you know how to greet a new pal?" the seraphim joked, though concern for Toriel's fate put an edge to his voice. He came to a stop right behind them, and a small, fearful sound escaped the human. Pity welled unexpectedly with him, so Sans stuck his hand out and said, "turn around and shake my hand."

Slowly, the human turned around, chin tucked, eyes down, and as he waited, Sans thought he might be left hanging. After a moment, though, they reached out and took his hand.

The sound of the whoopee cushion he'd palmed rippled through the silent forest with surprising volume, startling a laugh out of the human, who almost immediately snatched their hand back.

Sans laughed and pocketed the joke toy once more, grinning at the human in front of him who seemed to have relaxed a little. "the old whoopee cushion in the hand trick," he said with an appreciative sigh. "it's always funny."

The human tried and failed to muffle a giggle. "That's gross," she said, though judging by the way she was smiling, she'd found it just as funny as he had.

Sans found himself almost immediately inclined to like her, but the questions he'd asked himself back on the path forced him to reserve judgement and quickly put the impulse in check. "so, you're a human, huh? that's hilarious," he said, still grinning as he watched the human closely.

Under her crown of flowers, the girl's dark brown hair was cut in a bob to just below her chin, and her bangs fell in a straight line across her forehead. Her skin was pale and freckled, and though she was clearly amused, she refused to make eye contact with him.

"What's so funny about being human?" the girl asked, tilting her head to one side in question, lips threatening a pout as she waited for his answer.

"nothing particular," Sans answered. "just don't get many of you around these days is all," he said nonchalantly, then asked, "you just come from the ruins?"

The girl nodded, and Sans found himself wondering if humans were getting shorter. This one was even shorter than him, which was unusual, considering he was only four foot nine. Then again, it'd been a long time since he'd been in close proximity with a human. Maybe his memory was going…

"what'd you do to toriel?" he asked more bluntly than he had intended. Still, if this human had done something to his fellow seraphim…

"Are you Toriel's friend?" the girl asked hopefully, giving Sans pause in his suspicions.

"yeah," he admitted. "the name's sans."

The girl's face positively lit up at this news. "Oh!" she said, then started to rifle through her pockets. Sans' brow furrowed in confusion at this reaction, though his interest was certainly peaked. "My name's Frisk," the human explained, then found what she had been looking for and held up a familiar, cream hued feather for his inspection. "Toriel told me to give you this if I met you!" Frisk explained. "Didn't think I'd meet you so soon, though," she admitted thoughtfully. "I thought you lived far away or something."

Sans stared at the proffered feather long enough that Frisk actually waved it at him a little, clearly expecting him to take it. The skeleton gave himself a mental shake and quickly plucked it from her waiting fingers. He hadn't seen his friend since the day she'd sealed the Ruins, but he would never forget the color of her wings. Every angel's feathers were unique, and while you'd find some in similar hues, no two were quite the same.

"What's it for?" Frisk asked, making Sans blink and look at her once more.

"it's..." he mulled the thought over for a moment, then said, "call it a boon."

The human tilted her head again, frowning a little. "What's a boon?"

Amused by the girl's almost bird-like mannerisms, the seraphim answered, "it's like a favor, i guess. by giving me this, she's saying she owes me a favor."

"Oh," the girl replied, thoughtful as she processed this new information. "Why does she owe you a favor?"

Sans absently twirled the quill of the feather between his fingertips, then slipped it carefully into his jacket pocket with a sigh, knowing just what it was his old friend was asking of him. The why of it, though, was beyond him. Unfortunately, he doubted she had told Frisk.

"because it's her way of asking me to keep an eye out for you while you undergo the trials," he explained. "and, bonehead that i am, i'm gonna do it."

"Really?" Frisk asked, clearly surprised, and the relief that washed across her small, round face plucked at Sans' heartstrings in a way he hadn't thought they could be played anymore. After a moment, though, the expression faded a little and she asked in a more guarded tone, "Why?"

Sans shrugged. "because tori's a friend," he explained. "pretty much the only one i've got." He paused, then asked in a guarded tone of his own, "was she...alright when you left her?"

Frisk's brow furrowed, and Sans could read the sadness in every facet of her. For a moment, he couldn't breathe, fearing the worst. "I made her sad," the girl admitted unhappily. "She wanted me to stay with her in the Ruins, but I said no." To Sans' horror, tears threatened at the corner of her half-lidded eyes as she continued, "Sh-she said I had to prove my strength if I wanted to leave; that I had to fight her."

"And did you?" the skeleton asked, empty smile on his face as he waited for her answer.

"No!" Frisk replied with a petulant stomp of her foot that pulled a snort of amusement from Sans, something he was capable of only out of sheer relief that his friend had apparently left Frisk's first trial miraculously unharmed. "I said no, even though she threw fire at me and tried to make me mad!" the girl insisted, clearly unhappy at this, though her mood quickly softened. "She stopped, though. I told her I didn't want to, and she stopped."

"What, just like that?" Sans asked, incredulous at this turn of events. Traditionally, each trial was composed of some sort of task, and ended in a fight with the angel that ran it. It didn't have to be to the death for the angel, though there had been those humans in the past who had taken their opponent's life, rather than spare them. This sort of choice, unfortunately for them, always caught up with them eventually…

To hear that Frisk had made it through the first challenge without so much as landing a hit, though, was...well, unorthodox to say the least.

"She tried to set me on fire!" Frisk countered, clearly taking offense at how light he made of what she had gone through.

The seraphim laughed, a little off kilter from this strange turn of events. What a day. The first human to appear in years showed up just in time to meet him after somehow making her way through the first trial without shedding a drop of blood. It sounded like some sort of joke; or wistful thinking at the very least. "right, right, sorry," he apologized quickly and tried very hard not to laugh at the frown on the girl's face.

The more he watched Frisk, the more her mannerisms tugged at something in the back of his mind. The last human he'd interacted with personally had died by his own hand, so on first meeting Frisk he'd wondered if he'd simply lost touch with what humanity was like. He knew this couldn't be so, though, not really. He'd had many human friends on the surface, and frequented the village at the foot of Mt. Ebott almost daily. It may have been two hundred years since those halcyon days under the sun, but he had too many memories of mankind to really doubt himself for long. Granted, most of his memories fixated on one human in particular…

Sans gave himself a mental shake, not daring to venture down that road of thought now, not after so long of carefully avoiding it. Instead, he turned his attention back to the human before him and asked, "hey, frisk. how old are you?"

There was that bird-like tilt of the head again as she listened to him speak. "Oh," she said. "I'm ten years old last month," the girl answered proudly.

Sans felt as though the ground had dropped out from beneath his boots.

" what, " he asked, praying to the creator that he had misheard her.

"Ten!" she repeated, "I'm ten years old!"

Sans opened his mouth to say something, but couldn't even begin to put his thoughts into words. A child. A human child was going to have to fight his brother, assuming she made it through all his puzzles first. This child was going to have to fight Undyne, most powerful of the archangels that ranked just under seraphim such as himself, Toriel, and Asgore. A child was going to have to get through Hotland and that metal idiot Alphys made, and then she'd have to make it past his own trial to face Asgore, commander of the heavenly host…

The seraphim laughed loud and long, and judging by the wary look Frisk was giving him, a little bit hysterically.

"What's so funny?" she asked, clearly irked by his mirth, though unsure of its reason.

It took a moment, but Sans eventually managed to reign himself in and catch his breath, thoughts still spinning at the enormity of the situation. God in heaven, no wonder Toriel hadn't been able to bring herself to lay a hand on Frisk, not after losing her own son at almost the exact same age as this girl. So why hadn't Toriel kept Frisk with her, then? That was what she had vowed to do that day in the snow five years ago, after all. Was this human child really so determined as to defeat Toriel's notoriously iron will?

Sans looked Frisk over speculatively. She didn't look like much. She could have been any one of the human children he'd seen playing in the village two hundred years ago when he'd been guardian to the sacred lands that made up Mt Ebott. Granted, little girls definitely hadn't been allowed pants back then, but that was besides the point. The point was that, through no fault of her own, Frisk was clearly just some kid in way over her adorable head.

"life, i guess," the seraphim mused with a tired sigh, a smile playing across his bony features as he resigned himself to the fact that he was going to have to take this precocious child under his wing, both literally and figuratively. Stars above he just wanted to go lay down in the nearest snow drift and pretend none of this was happening… Ellie would never forgive him if he did, though. Ellie had always had opinions about the kind of person that didn't watch out for children, whether they were theirs or not. Sans gave himself a mental shake and asked, "so, did toriel explain the trials?"

Apparently content that Sans was no longer laughing at her, Frisk nodded thoughtfully. "She said I'd have to do a bunch of challenges and… and fight people if I want to get back home."

Sans nodded, "that's about the gist of it. toriel was the first challenge, and you beat her… i guess," the skeleton absently scratched one heavy brow as he mulled this over, then shrugged and continued. "so next is my brother, papyrus. he likes… puzzles."

"Puzzles don't sound so bad," Frisk said, seeming so hopeful that Sans couldn't quite bring himself to say anything else on the matter to save bursting her bubble. It was true, Papyrus' puzzles weren't bad, so long as you had half a brain in your head (which he swore his brother didn't sometimes), but he was no slouch when it came to fighting. Refusing to do so had worked out for the human the first time… question was, would it work out so well again?

"easy peasy," Sans said, then motioned for her to follow, "come on, it's up this way, unless he went and rearranged them again."

Frisk started after him, then stopped short, worrying her bottom lip with her teeth for a moment before asking, "Um… can I hold your hand?"

Sans paused glanced back at the girl, not having noticed her hesitation once he'd stepped out onto the bridge. It was funny, she didn't strike him as the clingy type. Still, maybe it was the bridge. Though the idea was foreign to angels, he recalled that many humans had a problem with heights. Not having the reassurance of wings to catch your fall would do that to a body, he supposed.

"yeah, alright," he said and held out his hand to her, which she took almost immediately. Sans did her the kindness of not commenting on the inordinate expression of relief that overtook her face when their hands met and they started walking again.

They crossed the bridge in silence, but rather than release her hold on him once they were across, her grip tightened a little. "I'm not a baby, you know," she insisted, and it seemed to Sans that this were a very important point for her to make for pride's sake. "I just-"

"don't worry about it, kid," he said, waving off her concern as they continued walking, boots crunching quietly over the snow covered path.

Silence fell over them as they traveled, and despite the pretty snow-covered vistas that appeared occasionally through the treeline on either side of the path, Frisk kept her gaze resolutely downward. He considered commenting on it, but she beat him to the conversational punch with an observation of her own.

"Your hand is really boney," the girl commented as she adjusted her grip on him a little, presumably for her own comfort.

Sans laughed, appreciating her ice breaker joke for what it was. "very funny, kid."

Frisk tilted her head and frowned a little. "Why?"

The seraphim's chuckle died off as she continued to frown rather than breaking into a smile in recognition of her own joke. Uncertainty began to tug at him, then, and his smile faltered. "well, i mean," he chuckled half-heartedly, silently begging the girl to crack a grin and release him from this conversational purgatory. "i am a skeleton," he finished, uncharacteristically sheepish in the face of her continued silence.

"You are?!" Frisk demanded, her hand tightening around his reflexively, then dropping it altogether, as though he had burned her.

They stopped in the middle of the path and Sans rounded on the girl. "well yeah!" he exclaimed incredulously, throwing his arms wide. "What are you-"

It clicked then, and he felt dangerously close to falling right off that mental cliff and into a dark pit of hysterical laughing he wasn't sure he'd be able to crawl back up out of.

"blind..." he said, voice small as he stared at Frisk. She wouldn't meet his gaze, hadn't since the moment they'd met. She tilted her head not just in question, but to better catch his words when he spoke. "Holy hell," he groaned as he slapped his forehead with the palm of his hand.

"You didn't know?! " she demanded, clearly taken aback. "How did you not notice? Do they not have blind people here?"

"no!" Sans said, horror sinking in deeper by the moment. Oh god. He wasn't just guiding a ten year old girl through the seven trials of the Underground, he was guiding a blind ten year old girl through the seven trials of the Underground. "angels don't...we just heal!"

"Well, sorry I'm not magic," Frisk said sourly as she crossed her arms over her chest. After a moment, her expression turned thoughtful and she said, "Well… I guess that explains why Toriel never said anything."

The skeleton dragged his hands down his face and said, "if toriel had known you couldn't see she'd have chained you up in the ruins and never let you leave." A question occurred to him, and he asked, "how did you even make it through the ruins?"

Frisk grimaced at the thought of being chained up. "I had a stick I was using to help find my way," she explained. "It got burned up when Toriel attacked me with fire, though."

A horrified mantra of 'oh my god' seemed to be on a loop in Sans brain as he listened to the girl talk, and for the first time in a long time, he found himself frozen by indecision. What should he do? In accepting Toriel's boon he had gone and made himself honorbound to see Frisk through the trials until she either triumphed, or died trying. On the other hand, there was no way his fellow seraphim would have ever let the girl out of the ruins if she'd fully understood her situation, no matter how much she cried and begged. Maybe he should take her back? Surely Tori would open the door if he explained…

"Sans?" Frisk said, pulling the skeleton from his internal debate to look at her again.

"yeah?"

"Are you going to take me back to the Ruins?"

Sans paused before answering, the lights of his eyes searching the little girl's upturned face. She was pensive, lips pulled into a frown as she absently adjusted the crown of flowers on her head. "i should," he answered finally.

"Please don't!" the girl begged, taking his hand again and clutching it in her own. "Please, please, please don't take me back. I have to go home!"

"kid," Sans said, torn as he watched her expression contort into one of desperation. "i don't think you understand just how much trouble you're really in with these trials," he insisted, all hint of a smile gone from his face now as it occurred to him that he had a very real duty to this lost child that had stumbled into his company. It was a burden he had no desire to carry, but it was one he'd shoulder all the same.

What else could he do?

A small, niggling part of him suggested that he could always just leave the girl there; turn and walk away. He could pretend he'd never bumped into her and let the trials play out as they had so many times before. He wouldn't even have to be the one to kill her, most likely. There was no way she'd ever make it past Papyrus, let alone Undyne or the Hotlands. He could just step aside and let nature take its course…

His very soul revolted at the idea, and Sans felt ashamed for even thinking it. No, he'd always been an angel of his word, and he wasn't about to change that now just to save himself the pain he would surely suffer when the little girl holding his hand so tightly in her own was inevitably cut down by one of the archangels. The kind thing to do would be to keep her company for the remainder of her time, make things that little bit easier for her, perhaps even ease her fear when the time came.

"you might die," he told the child bluntly, trying one last time to turn her back for her own sake. "do you understand that? did toriel explain? the archangels will be trying to kill you at the end of every trial. you managed to scrape by toriel, but you've got six more to go, and not a single human has made it to the final trial in the two-hundred years we've been stuck down here."

Frisk opened her eyes fully for the first time since they met, allowing Sans to make out their hazel coloration as she stared unseeing up at him. The girl opened her mouth to speak, but nothing came out, and she dropped her head, eyes slipping closed once more. With his hand still gripped tightly in hers, the seraphim could feel the fine tremors that shook her as she nodded. "I have to… I have to go home," she repeated. "I promised."

"is your promise worth dying for?" Sans asked with a frown.

Frisk's head jerked up at his question, and she scowled. With unusual insight for a child her age, she snapped, "I'd just die down here eventually anyways! Just slower and… and locked up!"

A laugh escaped Sans against his better judgement at her declaration. "you're not wrong," he mused. "if you tell me you want to go on, i won't bring it up again," the seraphim told her. "or, i can take you back to toriel right now and we'll forget all this ever happened. what's it gonna be, kid?"

Clearly unused to people taking her seriously, Frisk actually took a moment to consider his question, for which Sans was grateful. If she had jumped in with an answer directly, he wasn't sure he could take her words to heart. Granted, it was bad enough that a ten year old was having to make life and death decisions, but things were what they were, whether either of them liked it or not. This wasn't the surface world, and the trials of the Underground had rules all their own. No doubt he was violating at least five of them just for offering to take the girl back to the Ruins, but he never had been much for following the rules. No one had to know Frisk ever stepped foot in the Underground…

"I have to try," the girl answered eventually. "I have to go home."

A small sigh escaped Sans, but he smiled. "alright," he said, then glanced around as a thought occurred to him. "wait here a second," he instructed the girl before carefully extricating his hand from hers and stepping off the path towards the treeline.

Frisk did as she was told and remained on the trail, head tilted slightly to one side as she listened to Sans trudge through the snow away from her and proceed to rummage around in the underbrush. He was a strange person, this seraphim who also happened to be a skeleton, but she found herself liking him anyways. While funny, Sans also took her more seriously than any other adult she had ever known, except perhaps her Grandma, and she appreciated that.

There was the sharp crack of wood breaking, followed by a quiet curse that Sans no doubt thought she couldn't hear. "No cursing!" she chastised her new friend. "Grandma says only sailors and the wicked curse."

Sans laughed as he returned, realizing that the girl's hearing was even better than he'd expected. He'd barely even muttered the swear when the branch he'd torn free of a tree had come loose unexpectedly and dumped him on his back in the snow. "what about wicked sailors?" he asked, smiling as he stripped the branch of stray twigs sprouting from its length.

"They're worst of all," the girl answered with a sage nod, then asked, "What are you doing?"

"happy birthday," the skeleton told the girl in lieu of answer, then gently pressed the stick into her hand.

"But it's not my birthday," Frisk said with a laugh as she accepted the gift and ran her hands along it. The stick was just the right length, and felt quite sturdy without being too heavy for her.

"picky," Sans said with a tsk, watching the girl give the stick an experimental swing, then tap it firmly against the frozen ground.

"Well, I guess it is my un birthday," Frisk said with a grin as she adjusted her hold on the stick so she'd be able to feel her way. "Thanks, Sans," she added happily, clearly relieved to have a new means of navigating the world safely.

"unbirthday? that's a new one," Sans mused as he watched her test the stick. His smile widened when she thanked him, and found himself feeling strangely gratified by her obvious appreciation.

"Any day that's not your birthday is your unbirthday," Frisk informed him brightly as she started walking, stick tapping lightly back and forth across the ground in front of her. "I read it in a book about a girl named Alice that fell down a rabbit hole and ended up in a weird kingdom where there's a tea party with mad people, and a white rabbit that's always late, and the queen wants to chop off her head."

Sans trailed along beside the girl, careful to stay out of reach of her stick as he listened to her chatter. "sounds kinda familiar," he remarked with a grin.

Frisk tilted her head to one side thoughtfully, then smiled and said, "Yeah, I guess so, huh? Will there be a tea party with mad people, do you think? I like scones."

"well, there's plenty of mad people here, for sure," Sand admitted, deciding to steer clear of the possibility of beheadings for the sake of not frightening his young charge. She'd have more than enough of that later when it came time to fight Papyrus, after all. "hey," he said, grin widening as he nudged her lightly with his elbow. "how does a crazy person travel through the woods?"

The girl pondered the question for a moment, then gave up. "I don't know. How?"

"they take the psychopath, " Sans answered smugly.

Unfortunately, he wasn't rewarded with the laugh he'd expected. Instead, Frisk asked, "What's a psychopath?"

The skeleton sighed, a little disappointed, though he chuckled all the same and explained. "It's a kind of crazy person."

"Oh!" Frisk said, then grinned. "That's funny!"

Sans rolled his eyes, but smiled and pushed the girl lightly. "well, better late than never, i guess."

AN: Thanks for reading this first chapter! Make sure to drop a review if you enjoyed, they really do help keep me inspired to write!
Thanks also to my sister, nighttimelights for editing!