It's a really good thing, you decide, that you have so much determination.

Because it's been nearly four days since you talked to Papyrus, and the trail has gone cold. Everyone else you've talked to pretty much say the same thing- Sans and Papyrus pretty much just showed up one day.

If you weren't so determined, you would have dropped it by now. But you were determined. You just have to be observant, and you're sure that something will come up.

And you're right, something does.

You're in the park. Sans, Papyrus, Undyne, and Alphys are with you. You all go to get nicecream...

But Sans doesn't get anything. And, looking back on it, you don't think he's ever gotten nicecream with you.

You ask him if he doesn't like nicecream.

"nah, i like it just as much as the next guy. i just can't eat it."

You frown. "You can't eat nicecream? Are you allergic or something?" That's a kinda strange thought. Monsters don't generally have allergies, you've found, and besides, monster food is mostly Magic, and doesn't have much to be allergic to in it.

Sans chuckles a little. "no, no, let me rephrase. i can't eat it in front of you."

That makes less sense than an allergy. You tell Sans that.

He gives you a look. "have you ever seen me eat, frisk?"

You open your mouth to say you have, but then you realize you haven't. You've seen him drinking, yes, all manner of liquids from ketchup to soda to water, but never eating anything solid.

Sans just laughs again. "yeah, that's what i thought. now, consider, maybe there's a reason for that, kiddo?"

"Well, I can imagine that." Undyne snorts. "You're already a total slob, so you probably just eat really messily."

Sans snorts. "messily? nah. i actually don't know what it looks like. i guess i just don't have the guts to see for myself, after people started telling me it looked so horrifying."

Papyrus frowns. "It's not that horrifying."

"well that's because you've lived with me your entire life, and you never saw it any other way. you're just used to it. i'm pretty sure it's terrifying."

"S-Sans," Alphys interjects, "we're all your friends. We w-won't think any less of you because of the way you eat. Y-you don't have to be embarrassed."

Sans shakes his head. "i'm not embarrassed. i'm just trying to save you all from terror."

"I bet it's not that scary." Undyne says.

"undyne, i literally cannot open my mouth, yet i somehow still manage to get food into it. i think it's probably at least a little frightening."

Undyne gives Sans a sidelong look. "I'll be the judge of that."

"no you won't. you won't even see it."

"Well I don't believe you. I bet you're just sloppy."

The edges of Sans' grin lift a little. "why don't you quit mouthing off at me, undyne?"

"SANS!" Papyrus protests, while Undyne looks a little annoyed that Sans would interrupt a serious conversation with a pun.

"aw, c'mon! that was a good one. anywhere else, it woulda left folks slack jawed!"

"Sans, that was AWFUL." Papyrus shouts, stamping one foot on the ground.

"awfully punderful!"

"NNNNNYEH!"

It's not until later, once you're home again, that you realize Sans had effectively used puns to pull away from that conversation. Because after that, no one talked about Sans' eating habits again.

And as you think back on the conversation, something occurs to you. Something that Sans said.

...you never saw it any other way...

It almost seemed like maybe...

Maybe Sans hadn't always been like that? Did he used to be able to open his mouth? What had happened?

You groan a little. It seems like the harder you dig for answers, the more questions you uncover.

Nonetheless, you add a note to your notebook.

•S can't open mouth. Always like that?

But you feel like, even though you don't know what it is, you've uncovered something important. Like you dug up one of those rocks with crystals inside, and even though it just looks like a normal rock, you just have to find the right way to break it open to find the crystals.

Yeah, this has to be important. Somehow. You just don't know how it all fits together. Yet. You'll figure it out, you're sure.

You just have to stay determined.

And it works. Your next hint comes only the next day.

But it's at a bit of a cost.

You're lying on your bed, playing a game on your phone, when someone knocks on your door.

"Come in!" You call, looking up.

The door opens. Sans walks in. "hey, kiddo. i happened to be nearby, and i thought i'd stop by 'n' say hello." He flops into the chair at your desk. "so, uh. hi."

You laugh a little. "Hi, Sans."

You and Sans chat for a little while. And then...

Then Sans happens to glance at your desk.

... The notebook is sitting on top of it. You forgot to put it away.

Sans' grin is as wide as ever, but his eyes say he's frowning. Your breath caught in your throat, you watch in fear as Sans reads over your notes.

This was a bad idea! You think. Flowey was right, this was a bad idea!

"... frisk... what is this...?" His voice is peculiarly emotionless. As he turns to look at you, there's only just a hint of anger in his eyes, nothing you would notice if you didn't know Sans pretty well. "are you profiling me?"

"I- I just-" you stammer under his hard gaze. You decide to tell the truth. "I-... I heard you talking to Papyrus-... about- about your dad, and I just wanted to figure out-- where- where he went-..."

Sans slumps back into the chair, his cold expression melting into an exhausted one. Well. More exhausted looking than he normally has. He sighs. "kid... that's a dead end path, frisk. he-... he's gone. and as unhappy as i am about that, as much as i'd like to see him again... well, there's no use in digging up old bones."

You blink a little. This isn't what you were expecting, not this sort of quiet reserve. You were expecting more of that "if you keep going the way you are now..." thing Sans did to freak you out when-...

Well. That one time.

And there's an expression on Sans' face. It's well-disguised, almost unnoticeable. You bet that it's only because of this conversation that you can see it at all.

It's sorrow. Deep, painful, biting sorrow.

This only strengthens your resolve to figure out what happened. You don't like seeing your friends hurt, and maybe if you figure this out, you can help Sans.

Sans sees your face. "that expression..." he sighs, standing up and walking over to stand beside you. "you're not going to stop, are you?"

You hesitate a moment. Then you shake your head.

Sans is silent for a long time, eyesockets closed. Then, slowly, he looks up at you. "at the very least," he says, voice barely audible, "let me offer a little advice. be very careful about what you're doing, and be very considerate of all the potential consequences." His eyesockets go dark. "B E C A U S E   R E S E T T I N G   C A N ' T   A L W A Y S   B R I N G   E V E R Y T H I N G   B A C K ."

And it's like you blink. Half a second of blackness, and then Sans is just... gone.

For a long time, you just sit there, shocked.

And you are so, so thankful Flowey is downstairs in the kitchen, because if he had seen that, he would be telling you he told you so.

§

A/N

And now Sans knows what's going on. He's certainly not happy about it.

Anyway, thanks for reading, and I hope you enjoyed it! Comments and votes are my Favorite Things, and every notification I get makes my day!