Sans was sitting on the sofa, distractingly watching a MTT program while he waited for Papyrus to come home. Part of him wanted to go look for Frisk, but Sans also knew that if he didn't give the kid some space soon, they would break. Sans knew that look of desperation on the kid's face from personal experience, after all.

The door slammed open, and Sans jerked, surprised. "what, papyrus, did you see a human or somethin'-… frisk?"

The kid's brown hair was a scruffy mess, strands falling over their eyes and twigs tangled in their hair. Frisk's breaths came in short, angry pants, and they stood, shaking, in the doorframe as they struggled to gain enough oxygen to speak.

"How could you?" The human finally hissed, lifting their head. Sans wasn't sure if he should be relieved that it was still Frisk's face, or concerned over the anger in the gentle child's eyes. "You… you knew, right?" They demanded, shoulders shaking from… was it anger or sadness? Sans rose to his feet, wondering what the hell could have happened in one day to make Frisk like this.

"frisk, i have no idea what you're talking about-"

"Why did you ask me about a third skeleton then?!" Frisk yelled. "You knew about Gaster, don't you?! Why didn't you tell me…?" Their voice cracked, and Frisk scrubbed at their eyes with their sweater's blue sleeve as their voice lost its rage. Tired, fearful uncertainty laced through the child's ragged voice. "Were you also using me, Sans…?"

Sans froze, eyes flickering as the ramifications of what had occurred hit him. Shit. Memories long suppressed hissed in the back of his mind, his vision flickering as Sans took a deep breath to control himself and calm down. He wasn't the one who was having issues right now, it was the kid he needed to focus on. "i… what happened, frisk?" He asked softly. "i can't help you if i don't know what's wrong. whatever you think i did, i swear i had no part of it… c'mon kid, you know me better than that…"

"I don't know if I do though," Frisk stammered, voice wobbling. "Sans I- he said he'll make you forget as well. I don't want that, Sans, but I don't want to do as Gaster says either. What do I do?! What do I do…?"

Sans helplessly stared back at the child, then glanced away, hands tightening into fist. "…come to my lab, frisk. i'll tell you all i know about gaster… and about myself. i guess it's high time i did."

.

Frisk followed Sans into his lab, blinking in confusion as Sans went to one of the drawers and pulled out the photo album again, flipping it open as his eyes flicked from page to page. On the page with the other smiling skeleton, Sans paused, and studied it for a moment for continuing past it. He flipped to the back flap of the binder, and as he lifted the flap a small piece of paper also fluttered out, drifting down onto the floor. Frisk leaned over, and picked up the small slip of paper in their hand as they offered it to Sans.

"take a look, kid. that's… part of what i wanted to show you," Sans murmured.

Frisk, confused, flipped the piece of paper over and puzzled at the crude drawing there. Three smiling people gazed back at Frisk, and there were two words scratched onto the bottom of the page.

"don't forget."

"paps drew that," Sans said, nodding at the paper. "it's a picture of… of our family. before uh, everything got not so great, paps and i used to live with gaster."

Frisk jerked, nearly dropping the drawing. "Gaster was your father?"

"…no. skeletons aren't natural monsters, you know? we were his creations, frisk. the weapons to one day free the underworld…" Sans trailed off, lost in thought. He shook his head, and sighed. "he raised us, sure. and at first he was kind. at first we thought of him like a father. then he ordered paps to test his powers by killing innocent monsters… and paps refused. he decided that being affectionate was making both of us weak, and we were tossed back into the lab to be treated as no better than lab rats."

"Sans… I'm sorry I didn't…"

"know? of course not, kiddo. no one does. not even papyrus," Sans said bitterly. "i was supposedly the 'smart one,' in gaster's eyes. so when he was given the task of researching DETERMINATION by the king, well. i was offered a chance. i could work as his assistant and in exchange, i could have a say in the experiments given to papyrus and me." Sans shrugged, stuffing his hands into his pockets. "i think he expected me to, uh, get out of all the experiments by giving them to papyrus."

Frisk glanced back down at the drawing, and shivered. "You didn't, though."

"nope. in fact, i did the opposite. all of the DETERMINATION experiments… i took them all in my brother's place. every last one of 'em. heh, and now, i'm left with the remembrance of each RESET as a gift from gaster. perhaps the only thing of worth he ever left me with, other than paps himself."

"I… I don't understand though. Why doesn't Papyrus remember? Why is Gaster after me?"

Sans closed his eyes and leaned against the wall. "some stuff happened. gaster did some dangerous experiment which ended when he fell into the core, and that was that. the whole place exploded, and the experimentations created a breach in the void where gaster had been. i was caught in the explosion, and when i woke up, gaster was gone, i could use shortcuts, and papyrus was crying over my body."

Sans opened his eyes, eyes narrowed into black slits. "and now you know why i don't tell anyone this stuff. too angsty, y'know? not my kinda story. i never got over my bone to pick with gaster, either."

"…I don't know what to say," Frisk muttered, stepping up to Sans and leaning against him a little. They glanced between him and the drawing, and then swallowed. "What should I do, Sans? SAVE him? He said he would give me control back then, but that… the other humans. He killed them in these experiments, Sans. – I'm scared."

"he what?" Sans stiffened, pulling away from Frisk to glance down at their face. "…i see. welp, it's late kiddo, so uh, don't worry about this, okay? it'll be fine, and it can surely wait until morning. let's go to sleep, okay?"

Frisk watched Sans's stiff shoulders for a moment, but didn't point out the clear tension in Sans's body language. "Okay," they said quietly. "You'll make sure Chara doesn't…?"

"of course. let's go watch that movie again, huh? we've only seen it what, twelve times? not too bad, if i say so myself. i'll go try and find a new one tomorrow… dunno if we've watched them all yet though."

Frisk half-heartedly laughed, and followed Sans inside the house. They fell asleep on the sofa quickly though, mind falling into troubled thoughts and worries so they twitched as they slept.

Sans stood over them, watching their chest rise and fall for a moment, before he teleported out of the room.

It was time he and Gaster had a little talk.

.

The iron door slammed open, dim light flooding into the dark room.

The figure in the room lifted his head and turned, grinning as he noticed his visitor.

(My my. Two guests in one day? How peculiar,) Gaster signed at Sans.

Sans's gaze narrowed further, irritation filling him at the sight of Gaster's sign language. "don't you dare start that, buddy, i know your voice works juuuust fine."

Gaster laughed and shrugged. (Perhaps it does. But habits are quite difficult to dispose of after so long. Why don't you go ahead and communicate in Wing Dings as well?)

"no. not gonna happen." Sans stayed a few wary paces away from Gaster, his left eye glowing a brilliant blue to light the place up, and he glowered at Gaster. "now. my friend tells me you're the one RESETTING the world hundreds of times. stealing the RESET powers off of innocent humans and experimenting on 'em until they break."

(What is your point here?)

"…haaaah. not even defending yourself?" Sans questioned, fists clenching. He was forcing his shoulders not to shake, because it had been many, many years since he had last spoken to Gaster and yet he was still so, so damn scared in front of this monster. He felt powerless and small again, and Sans hated the feeling.

(Why would I? We did things of similar caliber in the past. Or have you forgotten, Sans? We even conducted the experiments on your brother together. Don't depict me as some villain when you left me here to rot despite having the ability to help SAVE me long ago.)

Sans gritted his teeth, and finally his anger overcame his hesitation and he stormed up to Gaster to poke him in the chest. "of course i haven't. i haven't been able to forget a single thing you did to me, you asshole, but i was willing to forget even if i wouldn't ever forgive you for that. and now, what, you've made me RESET five hundred and twenty-six times because you were just experimenting on little kids?!"

Gaster leered down at the shorter skeleton, and leaned down towards him, his eyes staring emotionlessly into Sans's blazing blue one. (It didn't have to be this way, Sans. You could have injected yourself with DETERMINATION and SAVED me from the day you found me in this state. You knew how to. You're my creation, so who cares if you die on my behalf? That was your duty from the very start, Sans.)

Sans glared back up at him, then swiped at his face, as if he was brushing away his own dark thoughts, spun, and stalked back towards the door. "give frisk their RESET back. they did nothing to deserve this."

(No. Not until they do what I want. And trust me on this, S01, you don't want them to suffer anymore than they have to, so you should be the exemplary assistant and do as you're told.) Gaster signed as Sans paused and looked back.

The short skeleton didn't reply, just slammed the door shut on his way out so hard Gaster could feel the vibrations travel through the floor. The skeleton with emotionless eyes and a cold smile laughed softly, because he knew Sans better than anyone else.

Gaster had won this round. Sans was powerless to go against him.

.

Sans was up early for once. Unable to sleep the entire night, he had paced nervously and waited for Papyrus to wake up. It wouldn't be ideal for his brother to walk downstairs and attack Frisk while they were sleeping, after all.

But, more than that, Sans was pissed. Gaster had always been an abusive, two-faced scientist who didn't truly care about Sans, but Sans had thought that the last time he had spoken to Gaster would be the last. After the explosion, Gaster had just been so wretched, so regretful, that Sans thought maybe he would examine his choices and become something… better. If only a little bit so. Even if he didn't deserve SAVING no matter what he changed about his personality for everything he had done to Sans. Done to Papyrus. Now, though, Gaster had just gotten worse after all.

The Wing Dings, for one, was a disgusting tactic to throw Sans's position back into his face. And to do these RESETS to children? Frisk was going to end up a young adult trapped in a child's body, and Gaster didn't care. No, scratch that, Gaster wanted Frisk to die for him, and hadn't even told the kid that.

It was just… just so unforgivable that at every turn, Gaster was still trying to turn Sans into a cold, uncaring scientist to finish Gaster's dirty business. Sans knew very well what this situation entailed. If Sans kept quiet and encouraged Frisk to do what Gaster wanted… Frisk probably wouldn't live to get their RESETS back. But if he told them, if the two fought against Gaster… then what? How could Sans possibly fix this?

Shit.

Sans rubbed his forehead with his hand, then started as the door behind him creaked open. "SANS?" Papyrus asked. "WHAT ARE YOU DOING UP? DO YOU HAVE A SPARRING SESSION WITH UNDYNE, TOO?"

"uhhh… no. listen, paps, we have an uh, guest staying here. just for a few days, all right? they needed a place to go, so…"

"OH! THAT'S FINE! WHO IS IT?" Papyrus questioned. "I DIDN'T KNOW YOU HAD FRIENDS THAT NEEDED A PLACE TO GO."

"ouch, paps, that's harsh. it's our cousin, actually."

"…I SEE. WOWEE, I'M LOOKING FORWARDS TO SEEING THEM!" Papyrus said cheerfully. "ARE THEY HERE ALREADY?"

"yep. asleep on the sofa, hope you don't mind."

"GOT IT! I'LL COOK SOME EXTRA SPAGHETTI AS A WELCOME GIFT FOR THEM BEFORE I LEAVE!"

Sans sighed in relief, one issue resolved. He rubbed his head and started back down the stairs, when Papyrus's voice made him pause.

"HEY… SANS?"

"what is it?"

"IF- IF THERE"S SOMETHING WRONG, YOU CAN TALK TO ME ABOUT IT." Papyrus offered sheepishly. "YOU ONLY EVER PACE WHEN YOU'RE WORRIED. AND YOU'RE ALSO AWAKE AT THIS HOUR? IT'S STRANGE."

Sans sighed, and grinned over his shoulder at Papyrus. This conversation, San mused, had happened at least fifty times since Frisk had come into his life. "nah, nothing is wrong. just making sure you don't attack our cousin, they look a bit… strange."

"WHAT DO YOU MEAN BY THAT- SANS, IS THAT A HUMAN ON OUR COUCH?"

"my point exactly."

.

.

.

Frisk's DETERMINATION is somehow still strong.

((I'm sick, it's snowing, and instead of being busy for the entire weekend I am here with a computer and nothing to do. Thus, time for writing! I've come to realize I have a terrible habit of overusing ellipses. Will work on that, lol. Also, I'm ready for Toby Fox to smash my depiction of Gaster into smithereens this year, but for now, he is the fabulous evil scientist in this story. Also, to the guest that called me a "special breed of fruitcake": you review was hilarious and I am glad you liked my "evil" writing. Thank you everyone else, for your reviews as well! You guys didn't seriously think I would do two No Mercy routes did you? Nahhh.))