Sans recalled the first time he had ever met a human. When everything went wrong. (Again.)

After moving to Snowdin, his brother Papyrus had gotten them jobs as low level sentries. He wasn't happy about the idea, but they had to pay the bills somehow, and it turned out to be pretty easy. Nothing ever happened in that tiny town, just the way he liked it. So long as he could manage to avoid his brother, Sans mostly spent his time slacking off at his station. He pretty much got paid to do nothing; it was his dream job, really. The only real downside was that it was incredibly boring.

That is, until he found the door.

A huge, purple door at the edge of the forest. It led to the ruins of the former capital, if he remembered right, but it was locked up by that point. He wasn't interested in exploring anyway; what was appealing about the door was that it was perfect to practice his knock knock jokes on. (Only the best comedians went the extra mile to actually knock.) It made for a great way to kill time at work.

And it got even better, because someone actually answered him back. He hadn't been expecting anyone to be on the other side, but a woman's voice responded and when he tentatively gave the punchline, she had roared with laughter.

Sans couldn't have been more thrilled.

Most people just groaned at his jokes, and they downright irritated his brother (which was admittedly funny on its own but still not nearly as satisfying). But the woman's laughter was the most genuine and hearty he had ever heard. She even snorted a bit, and you couldn't get more sincere than that. Sans was immediately enthralled by the sound, and more pleased than he would have been with an entire audience.

And just when he thought it couldn't get any better than that, she started telling him jokes of her own. She was a pro too, just as good as he was. They had spent all day like that, telling each other bad jokes through the door. It ruled. Before Sans knew it, night had fallen (or what passed for night in the Underground), and for the first time he was disappointed that his shift was over. But the woman asked if he would come back, and he did. Again and again. It became a regular thing, and for a while, he forgot that he was even "working" in the first place.

Until the human arrived, and the fun ended.

He hadn't even realized it was a human at first. Everything he had learned and heard about humans led him to believe that they were practically demons, and that was putting it nicely. They were far stronger than monsters but lacked the capacity for love and compassion, making them ruthless creatures who would kill without a second thought. This created a rather nasty mental imagine, so once Sans had finally figured out what he had been looking at, he was thrown for a loop.

The human was just a mere slip of a thing, a little girl. Trying to catch snowflakes on her tongue. A red ribbon was tied in her bright yellow hair, and she wore a striped dress, a clear indicator that she was just a child, if her small stature hadn't made it obvious enough. Heck, she was shorter than Sans himself, and all in all, looked about as threatening as a puppy.

It wasn't anything near to what he had been expecting.

He hadn't let his guard down though, because he had noticed that she was, in fact, armed. Just like a human! Even the children were bloodthirsty, apparently. Ooor so he had thought, but strangely enough, the knife she had been holding had no glint to it. As he carefully approached her, he soon realized why: it was made of plastic, just a mere toy.

Just a kid.

And that kid had greeted with him a wholesome smile, not a trace of fear or malice to be found in her expression. She had insisted the toy was actually a legendary sword called Excalibur and pointedly addressed Sans as "Sir Skeleton". She told him that she was a hero-princess, on an epic adventure...to get home, because her parents were probably worried sick and she was going to be in a lot of trouble. But that was okay, she explained, because she deserved it. She had gone to explore Mt. Ebott when her parents had told her not to.

(There was a big hole in this Mt. Ebott that she fallen in, Sans had learned. That was how she had ended up in the Underground.)

She had been very chatty and charming and just plain adorable, as little kids are often are. No different from the monster kids in town, really. Her playful enthusiasm even reminded Sans a bit of his brother, which hadn't helped matters.

Because according to his job description, he was supposed to capture and turn in any humans he had found. It was royal decree. The king needed seven human souls to destroy the barrier that separated the monsters from the surface. A noble goal, in theory. But Sans was aware of how that process worked. There was only one way to take another's soul. And this...this was just an innocent kid, not the demon he had been expecting. It was one thing when it was faceless, evil humans, but standing in front of him was just a six year old playing make believe.

It had left Sans at a total loss. He didn't know what to do.

So, as was his specialty, he had done nothing.

He let the little girl go on her merry way, let her be Someone Else's Problem. Surely nothing bad would happen to her anyway, he had reasoned. The king loved kids. Even if he had hated humanity, even if they needed souls to break the barrier, he would never harm a child. Not ol' Fluffybuns. Sans just couldn't see it.

After all, he still had some optimism left back then.

News spread quickly of the human's capture and the entire Underground celebrated. They finally had their first soul, their first step to freedom. Everyone was a little more hopeful and happy, all save for Sans, though you couldn't tell. He smiled with the rest of them, like he felt he was supposed to do. But at the same time, he couldn't stop thinking about the little girl. How she had smiled at him, and how she wasn't smiling anymore.

He couldn't believe the king had actually gone through with it, but after it had sunk in, he found himself trying to justify it. They didn't have any other choice, did they? It was for the greater good. The girl's death wouldn't be for nothing, and besides, if anyone was to blame, it was the humans. They were the ones who had forced them into this situation in the first place.

Still, pushed to the back of his mind but stubbornly resurfacing, a part of him wondered if it was truly the only way. Maybe they had given up too easily on an alternative, and maybe...maybe he should have done something. Maybe that girl would still be alive if he had. Greater good or not, it didn't feel quite right, when he really thought about it.

So he tried not to think about it, and life went on. Well, for most people. (Trying proved to be sometimes difficult.) Once the human was gone, work continued as it had before, and Sans found himself going back to the door of the ruins. He hadn't spoken to his friend since the human had arrived, and he was in desperate need of some laughs.

Boy was that a bad idea.

He knew something was up almost immediately. There was no enthusiasm in his friend's voice, she offered him no jokes of her own, and her laughter was hollow and empty. It pained him to hear it; was there anything sadder than a forced laugh?

Well, besides a dead kid?

He should have known. The little girl had to have passed through the ruins, where she apparently had ran into his friend. But he only realized this after he had asked her what was wrong, and she replied with a strange question.

"If a human ever comes through this door," she said solemnly, "Could you please, please promise something? Watch over them, and protect them, will you not?"

Now, Sans wasn't one for promises. Keeping 'em was too much work. It was better to just not make any in the first place. That way, there would be no expectations and no disappointments; he'd already had enough those for one lifetime. And yet...

"yeah," he had told her. "i will. i promise."

He didn't even hesitate. This lady, he didn't know her name, what she looked like, who she even was, really...but he did know that she had a big heart, and a great laugh, and that just being able to talk to her made his day so much brighter. How could he possibly tell her no?

And weirdly enough, it was a relief. Now he had an excuse to do something, the next time a human appeared. He wouldn't just stand by as they walked off to their death. Technically, helping them would be treason, but it was out of his hands, wasn't it? He had made a promise, and he'd keep it, no matter what. Lazy as he was, Sans was a skeleton of his word.

Eventually, his friend started to laugh again. It was enough to make him think that everything would be okay, and that the promise had been worth it. But at the time, Sans had only been thinking about making the lady feel better, and his own lingering guilt. He hadn't thought about the consequences.

Those hit him later, after the second human had arrived. And then the third. And the fourth. One after another, a human would appear in the Underground. Each one was wildly different from the last, but they all had three things in common: they were always children, they were always determined to return to the surface, and they never, ever made it out alive.

Sans had tried to help them, to stop them, whatever it took, but in the end it was always the same. It was almost as if Fate itself was actively fighting against his efforts. And it hurt in ways he hadn't imagined.

Because in order to really protect someone, you had to care.

So he soon came to regret his promise. It was becoming too much. A human kid would show up. Sans would befriend them, try to keep them safe, try to convince them not to go, but it was no use. They always died, in the end. (For the greater good, he'd think bitterly. Innocent kids being sacrificed for the sins of their ancestors.) And then he would have to listen to the heart break in his friend's voice when he told her of his failure. Not that she ever blamed him, but somehow, that just made him feel even worse.

They'd eventually go back to their knock knock jokes and laugh again, because they had to laugh at something, to combat the bleak situation they had found themselves in. Unable to save a single child.

Over and over, this hopeless cycle repeated.

By this point, Sans had failed five times. (He counted the first one, the little girl's smile never fully leaving his conscience, even years later.) Judging by the footprints in the snow, leading away from the door to the ruins, it was about to be six.

Sans had been having a pretty good day, up until then. Things had been nice and quiet lately (or as much as they could be with Papyrus around) and he had just wanted to visit his joke buddy, to soak up the normalcy while it lasted. It was nice to pretend that everything wasn't awful for a while.

But he was too late. Another human had fallen.

He had taken a short cut to the door, so he hadn't seen them yet, but a quick glance to the right confirmed his suspicions. Not far away, a human was hunched over and shuffling through the snow. Sans looked longingly back at the door for a moment, then turned away with a sigh.

here we go again

Sans didn't set after the human right away, though. Instead, he stared at their back as they walked away, a strange sensation in his soul. He could feel the magic surge to his eye unbidden as the thought crossed his mind: how easy it would be, just to end this all now. A quick blast was probably all it would take; they wouldn't see it coming, wouldn't feel a thing. It'd be over and done with. No prolonging the inevitable, no false sense of hope, no suffering.

Why not have mercy, just this once?

But the magic faded away as quickly as the thought had passed. This wasn't the first time Sans had such thoughts, but he would never act on them. He had made a promise, after all. For better or for worse, he'd keep it. Even if it was pointless in the end, he could at least say he did that much. It was about all he could do.

And with that, he flipped the switch. It was all smiles now. There was a new pal to greet, and he had to make a good first impression. At least this was the easy part. The past and the future could be pushed aside for the time being; if he opened that endless matryoshka of "what ifs", he wouldn't get anywhere.

Sans took a step and a shortcut forward, reappearing behind a tree some ways in front of the human. He wanted to get a good look at contestant number six.

It was a girl. She was much older than the last human, a teenager by the looks of it, but still a child in his books. She was even wearing a button-up sweater with purple and white stripes. (What was it with kids and stripes anyway?) Mousy brown hair was pulled back into a practical ponytail, and her face...was suddenly buried in a pile of snow, after the girl had tripped out of nowhere.

Sans had to suppress a chuckle. It'd be rude to laugh, but he needed some laughter if he was going to get through this, and you couldn't deny the hilarity of a good old fashioned face plant. He'd give it a 9 out of 10.

He watched as the human shook the snow off her face, but instead getting back up, she remained on her knees and began frantically searching through the snow in front of her. Sans figured this would be a good time to step in and quietly approached her, wondering what she had lost before his mind started wondering how long she would last.

The girl was mumbling under her breath and too focused on her search to notice him, it seemed. Pausing before her, Sans glanced downwards and quickly spotted an indentation in the snow, just barely out of her reach. From this he picked up a pair of silver framed glasses. No wonder she was having such a hard time finding them. With his jacket, he gently wiped the snow off the lens and held them out in front of her face, where she couldn't miss them.

"looking for these?"

"Eh?!" She jerked her head up with a start and squinted her eyes. "O-oh! Thank you!"

With shaking fingers, the girl reached out and took back her glasses. She slid them back on her face, adjusted them a bit, then blinked and looked up.

Into the smiling skull of the skeleton standing before her.

There was a brief moment of silence, another blink, and then—she fell backwards and screamed.

ouch, Sans thought. He had freaked out some of the humans before, no doubt, and he understood why his appearance shocked them; skeletons didn't really get around much on the surface, as it was. (And his brother thought he was lazy.) But no one had ever straight up screamed at him in pure terror before. Anyone who knew him would have laughed at the very idea.

"No!" the human shrieked at him, "Y-You can't take me! Not now, you can't! I-I didn't even-"

"woah there bucko, calm down," Sans said, taking a slow step forward with his hands up and open, the way you might approach a skittish animal. He pushed his grin wider, just in case he maybe wasn't smiling hard enough, but this appeared to have the opposite effect from what he was going for. She just shrieked again and began crawling backwards, pushing herself away from him with every step he took forward.

So much for a good first impression.

"i'm not taking you anywhere," he tried to explain, though he was a bit confused on how she already knew that he was a sentry.

The girl finally came to a stop, but only because she had backed into a tree. A messenger bag was hanging from her left shoulder and she quickly pulled it up in front of her face, as if to shield herself with it. She lowered the bag just enough to peer out from behind, her eyes searching him up and down.

"You're, you're not... A-are you a monster?"

"you know it," Sans replied with a wink, even though she obviously didn't...wait, what did she think he was? But before he could ask, the human made a little "eep" noise and was cowering behind her bag again.

"Please don't hurt me!"

Geez, he had his work cut out for him with this one. Sans had never met a human this scared before. Then again, he wondered, was that really a bad thing? Fear was a survival instinct, something humans didn't seem to have a lot of, in his experience. But if the look on her face was any indication, this one had it in spades. Maybe it was something he could work with. Maybe this time...

He wasn't going to get his hopes up; he didn't have much left to begin with. But Sans couldn't help but feel just a tiny bit lighter. It was something, and something was better than nothing. A little fear could go a long way.

Course, they weren't going to get anywhere if the human kept being afraid of him. So, first things first.

"i'm not gonna hurt ya, kid. would i have bothered to give you your peepers back if i was?"

She seemed to consider this and the bag came down again, enough for her to watch him carefully from behind said peepers.

"just thought you could use a hand," he continued, literally offering the human his hand now, but her immediate reaction was to flinch back.

"cmon pal, throw me a bone here."

His friend would have found that hilarious, had she been there. The human, on the other hand...well, she just suddenly looked confused. Like she wasn't sure if she had heard him right or not. An eye brow was even raised, ever so slightly. He would have preferred a smile, but regardless, it did the trick: Sans knew it was hard to take him seriously when he was making cheesy skeleton puns. The only scary thing about that was that he had a million of 'em.

Another moment of silence passed, but then the human took a deep breath and finally, gingerly, accepted Sans' hand and allowed him to pull her back up on her feet. (It took a bit more effort than he thought it would, as it turned out she was about a head taller than him.) She was quick to retract her hand once she was upright again, but she did have enough humility to mutter a small "thank you".

"no prob," he replied, "and sorry if i spooked ya. guess that's what i get for going out without make-up, huh?"

The poor thing was too baffled to laugh, he assumed. She just stood there like a deer caught in the headlights. But it was better than screaming, so he could roll with that. She just needed some time to warm up to him, was all.

"i'm sans, by the way. sans the skeleton."

To his surprise, that got a giggle out of her, albeit a nervous one.

"N-no kidding."

"i never kid," he kidded. "so what about you, you got a name?"

"Um." She looked away and fiddled with the hem of her sweater. "Lainey..."

"well, it's nice to meet you, umlainey. welcome to snowdin forest. you have a nice trip?"

She gave him a pointed look, then let out a long breath and another nervous giggle. Whether it was out of relief or exasperation, Sans wasn't sure, but she looked significantly calmer afterward. Still cautious, but less tense, now that she seemed to accept that he wasn't a threat. With a bit of pride, he made a mental note of the effectiveness of his puns.

"This whole day's been a trip," she admitted.

"i bet. what's a human like you doing in a place like this anyway?"

The color instantly drained from her face, but he could tell she was trying to keep her composure. "Oh, j-just passing through..."

"right, right," Sans nodded. And then he suddenly turned around, waving a hand to her as he walked away. "whelp, good luck with that, kiddo."

"W-Wait!"

He stopped and turned back around expectantly. Lainey looked at him, then to her left and right, then back to him, uncertainty written all over her face. Her mouth opened then closed, her lips pursed, as she tried to figure out what exactly she wanted to say. Obviously, she had not planned this far ahead...if she had planned anything at all. Too bad glasses didn't help with poor foresight.

"Um."

"sorry, but it's about time for my break," he said, tapping an invisible watch on his wrist.

"Uh, a break from what?" she asked.

"all this hard work, of course! don't you know? i'm a sentry 'round these parts."

"Se-sentry?" Sans could hear the panic rising back into her voice. "Y-you're going to turn me in!"

Did he say that? He didn't say that. Sans shook his head and chuckled.

"and make more work for myself? nah. i get paid either way, so why bother?"

"But-" She cut herself off and hugged her chest, conflicted.

"you can come with, if you want," he suggested. "since you don't believe me. 'sides, you look like you could use a break yourself."

This appeared to only make the human more suspicious of him, but there was something strange in this fact. Sans noticed her hands clenched into fists at her sides and her once fearful expression shifted into a far more familiar look.

"Is this some sort of trick?" she asked, apparently forgetting that she was the one who had stopped him. "I...I know what happened to the other humans, you know!"

"...good.

then you know that it's pointless."

Sans hadn't meant to say it so seriously, but that look on Lainey's face...it was one of determination. And it remained, even after he spoke. It wavered a bit, but she held on.

He had been afraid of that. If a human as frightened and timid as this could still dredge up some determination, then maybe...it was just flat out impossible.

"so listen kid," he said, more gently this time. 'just quit while you're ahead."

"I can't."

Of course not. They never could. They always had to go back. The surface must have really been something, if they were so willing to risk their lives for it. Sans wasn't going to argue with her now, though. They had just met, and he was already tired.

He really could use that break.

"suit yourself," he said with a shrug. "so you coming or what?"

"You're really...not going to take my soul?"

"nah, i already got a sole. two in fact."

Sans lifted up his foot and tapped the bottom of his slipper. And suddenly, the tension evaporated. A smile spread across Lainey's face and she laughed into her hand. It wasn't like the joyous laughter of his friend, but rather the unbridled laughter of relief, and absurdity, and maybe a little bit of delirium. Because she was human trapped in a world of monsters, currently being confronted by a skeleton wearing pink fuzzy house slippers, and you had to laugh at something.

"hey, don't judge. they're comfy."

"How can you..?" She laughed some more and shook her head. "Never mind."

Sans flashed her a wink and started off for his station. A few seconds later, he heard the human's footsteps crunching in the snow after him.

A/N:

Fun fact: I was originally going to name Frisk's sister Frolic.
But then I realized that was, like, Asgore levels of bad.