Things at home were infinitely better due to the simple fact that Papyrus survived that day. But...things seemed to only be getting worse at the research lab. By this point, everyone in the group of five had reset, and the effects were becoming obvious. As far as Sans knew, he was the only one who had reset twice, but the others seemed as lethargic as he was after only one. There also seemed to be...much fewer monsters than he thought they had started with, but for the life of him he couldn't remember who the others had been. Maybe they had dropped out from the stress of the work.

He still wasn't on speaking terms with Gaster. Maybe he wouldn't ever be. But the research needed him, and, quite frankly, he was still just as desperate for information on resets as he had been when this whole mess had started.

But...not much work was getting done today, admittedly. Sans, exhausted as anything, kept dozing off against his notes. He sat up straight as he heard a soft voice.

"Sans?"

His head shot toward the source, then he relaxed. "Oh, hey, Terrin," he greeted easily, though his brow furrowed as he looked the fish-girl over. "You, uh, you all right? You look a little green around the gills."

She managed a weak smile. "I just...wanted to talk." She gestured at the poorly-drawn doodles on his notes. "You, um, didn't seem all that busy."

"Heh, guess not. So what's up?"

She half-smiled. "God, it was so much easier last time..."

"Last ti-"

"Look, I have...I have a massive crush on you. And, um..." She swayed slightly on her seat. "Wow, sorry, I am...really tired..."

"Did you reset? Again?" Sans asked quickly, catching her arm to keep her steady. She looked up at the ceiling.

"I was just...I mean, you said yes last time...well, you actually said 'sure, why not,' but I...I said something stupid about your brother and...and I just thought that I could...fix..." Her mouth went slack, and Sans jumped up to catch her as she fell out of the chair.

"Terrin? Terrin, look at me!"

Her head lolled back, and the color drained from her face. Sans stared in horror as she began to melt right out of his hands.

"Gaster!" he cried out, looking around for the other skeleton and vaguely aware of the others' cries of horror as...whatever Terrin melted into seemed to seep out of existence. The elevator from the downstairs lab whirred, and Gaster threw himself out of it just as the last bits of Terrin seeped away.

"Write this down!" he barked out. "Anyone!"

"We ha—"

"Write this down!"

Sans remained frozen for a moment, but he finally forced himself to move enough to grab a pen and scrawl out, "Terrin gone, melted, reset?" over his notes.

He turned back to look at the others. Why was he breathing so hard? The others were looking at each other blankly, and Ceris held her head.

"Did, uh, did something happen?" she asked, breaking the room's silence. Wynn scratched his ear aimlessly.

"Maybe there was another reset?" he suggested. "Is it like déjà vu?"

Ceris shook her head. "No, it's...I dunno. It was something scary."

Sans merely sat in silence. What had happened? Why did he feel so sick? He hadn't felt this shaken up since before his last reset. He didn't even shift away as Gaster walked over to his table and picked up his notes. The scientist frowned.

"Terrin gone...melted...reset," he murmured. Sans glanced up at him; that was more disjointed than usual.

"Hey, yeah, whatever happened to Terrin? She was...I mean, she was pretty cool, right?" Ceris asked.

Gaster sucked in a breath, sockets widening. "No...no, no, no...This is what I feared." He ran over to his desk, digging around in the drawers. Eventually, he pulled out a picture and beckoned the group over.

"Please, everyone, look." He held up the photo. It was the one Ceris had taken of their first day in the lab. He tapped on one monster's face. "Can anyone tell me his name?"

Silence.

Gaster tapped another monster's face. "Or hers?"

"That's, uh...that's Lonn...I think?" Tephra said with a shrug.

"No, no, that's, um...Suzy?" Ceris tried.

Gaster sighed, setting the picture down. "And now Terrin." He looked down at Sans' notes and shook his head. "This confirms what I had been afraid of. We all know that working with time is difficult on our bodies, and repeated resets are...more than deadly. It...I am not entirely sure, but I can hypothesize that you essentially are...erased out of time." He pressed his hand to his browbone. "Please, do not reset again. Unless...unless it is for the sake of the Underground, it is not worth the risk." He let out a sharp breath. "We are ending the session today. I must go try and find..." He glanced at the notes again. "Terrin's family."

Gaster abruptly left the lab, and the three other researchers wandered out afterward. Sans, however, couldn't bring himself to move. Terrin, whoever she had been, had apparently just...faded from existence altogether. That was impossible. He had to remember it somehow.

He couldn't just forget.

~

He must have sat there for hours, wracking his brain for any trace of Terrin, but with no luck. Eventually, he gripped his head and let out a frustrated grunt.

"Sans?"

He sat up quickly, hands still on his skull. Gaster's browbone furrowed.

"I did not expect you to still be here."

Sans shook his head and let out a quick breath. Finally, he yielded to his need to talk. "I should remember what happened, but I...I can't!She disappeared and I saw it and I know it had something to do with me. But I-I can't even remember what she looked like!"

Gaster set his hands on Sans' shoulders. "I realize that this is difficult to...er, process," he said softly. "But we must press on. The resear—"

Sans grunted again, pulling away from the other skeleton and whirling around to face him. "God! Do you care about anyone?"

Gaster stared at Sans with wide sockets. "Sans, I—"

"It's always the...the process, the research, the timelines! You don't care who gets hurt!"

The scientist looked as though he'd been slapped across the face. His hands fluttered, but they didn't quite make a word. Sans glared at him, ribcage heaving. Was he going to defend himself? Apologize? Anything? Sans' jaw trembled.

"You're as bad as the humans," he spat.

At that, Gaster's whole expression shifted into one Sans had never seen. His sockets were alight with fury, and his mouth twisted into an ugly frown. In two swift strides, he was in front of Sans, gripping his jaw hard enough to hurt.

"Do not ever compare me to them!" he snapped, forcing Sans to look at him. "You have no concept of what humans are, the horrible things they do!"

"I know they let others die just for their gain!" Sans snarled back, fighting against Gaster. Two resets ago he would have been able to break away, but the scientist was surprisingly strong. "Progress is all you care about! You can't even pretend sympathy when someone--"

"You know nothing of the loss I have faced!" Sans recoiled as much as he could as Gaster shouted in his face. The scientist took several deep breaths, then narrowed his sockets. "You would like to know what it was like above ground? It was hell. I watched my people be slaughtered. My village was filled with their dust; it clung to me for weeks! I come down here to spend centuries alone, my language is useless, but I adapt. Isurvive. And I am rewarded by finding the first skeleton in a thousand years, but I see now that he is no more than an impudent child who has the gall to compare me to the creatures that murdered my kind!" With a sharp breath, he pushed Sans away and turned his back on him. "Get out of my lab," he said coldly. "Do not come back."

Sans didn't move. His bones rattled slightly as he shook; he was furious, shocked, overwhelmed.

Gaster glanced coolly over his shoulder. "Was I not clear?"

Sans didn't speak, merely sucked in several shaking breaths until his eye suddenly blazed blue. With a sharp cry, he shot several bones right at Gaster. The scientist merely flicked his wrist, and a wall of bones as tall as he was shielded him, leaving Sans' attack to clatter uselessly to the floor.

"Is this a sign that I am being judged?" Gaster asked dryly, swiping his hand to send the bones away. "You may as well tell me my sins."

It took Sans a long moment to speak. "You're a heartless liar," he said, voice shaking. "Yo-you pretend to care about other skeletons or the researchers, but when they die, you have n-no idea what grief is. You say to 'press on' when someone's erased from our memories. You...you ca—" Sans felt tears gather in the bottom of his sockets as he choked out, "You called me selfish when I saved my brother!"

Gaster blinked, and his stony expression softened somewhat. "I...do not recall that."

"Papyrus died!" Sans cried out. "Some...some thing killed him, and I ran out to the wishing room and I..." He sniffed. "I reset to save him. And you called me selfish for that!" He shook his head. "I can't believe that you care about anyone if that's what you think about saving the only family I have."

Gaster watched the other skeleton for a long moment, and he finally shut his eyes. "You are very young," he said softly. "You are thinking in absolutes." He half-smiled. "And I cannot tell if I should be offended or flattered that you apparently used to hold such a high opinion of me that a mistake like this sent it crashing down." He sighed and dropped onto one of the nearby stools. "Am I allowed to plead my case?"

Sans didn't move, but his eye faded back to normal.

"I will take that as a yes." Gaster was silent for a long moment, his hands moving as he gathered his thoughts. "You see, just because I am a scientist does not mean I am always inclined toward rational decisions. I...cannot tell you what my motivations were in your last timeline, because it was not me, strictly speaking, who said that. But...whatever my thought process was, I, in this timeline, would be with you in saying I was in the wrong." He sighed, suddenly looking quite brittle. "I do know loss, Sans. But my loss came with war. There was no time to mourn; I had to press on or risk being killed as well. Whatever has happened to the other researchers is a tragedy. But we mourn in different ways; I try to find the root of the problem, and you...well." He gestured to the bones scattered on the floor. He sighed again. "Perhaps this is not enough. Perhaps whatever the other me said is enough to ruin your view of me forever. I have said all I can."

Sans stood stock still, remaining silent as Gaster finished speaking. He was tempted to teleport out, but equally tempted to throw himself at the other skeleton like a kid, to tell him how sorry he was for treating him like this, how tired he constantly was, how...terrified Terrin fading away and Papyrus' death left him.

"I...I have to go," he finally said, turning and pulling up his hood. He heard Gaster let out a small breath.

"I will not stop you," he said. "Though...this reset, it is your second, right?"

Sans swallowed. "Y-yeah."

"And I assume this is why your mouth has not moved?"

Sans didn't reply to this, instead pulling his hood tighter. So he had noticed.

"Regardless of whether you associate with me or not, Sans, please be careful. I cannot stop you, but..." Gaster's voice caught. "I would not want to forget you. It would be like losing a—" He cleared his throat. "I am sorry. I will not keep you."

Sans kept his hold on his hood, standing there for a moment longer. Finally, he shook his head.

"Bye," he said simply, then teleported out.

~

He didn't return to the lab for a while. Really, he didn't do much of anything for a while. Mainly he just laid on the couch, staring at the ceiling and trying to remember that Terrin person as well as sort out the fight he'd had with Gaster. This, naturally, earned him several chidings from Papyrus about the wrongs of being lazy. The first week, he was able to divert him with some jokes, but soon enough it was clear that even Papyrus wasn't being fooled. The lectures stopped.

God, he wished he'd just left all of this alone. If he could go back in time...well, no, that's what started this whole mess. But he resolved to himself then and there, no more resets. Never again. He had obviously been lucky with the second one, even with all the troubles it had brought. He couldn't risk fading away from memory. Hell, he couldn't even remember how many had been in the research group; had they all disappeared like that? How many monsters had met this fate?

He couldn't have given an exact number as to how many days he spent like this, but it was all brought to a halt as Papyrus dropped something onto his chest, waking him up from a doze.

"Jeez!" He sat up and rubbed his chest. "Give a guy a little warning before you drop in like that, Pap."

Papyrus, for once, didn't react to the pun, instead shifting back and forth. "Sans, I've...noticed you haven't been doing much lately. And I thought it was your usual laziness, but then it just...kept going..."

Oh. God, Sans didn't want to have this talk. "Papyrus, look, I—"

"So then I realized you must be bored!"

Sans blinked. "Uh..."

"Because you haven't been going to any of your jobs! And so I decided to fix it!" He gestured down to the thing he had dropped: a little badge with a delta rune on it. "So I've signed us both up to be sentries in Snowdin!"

"Uh, gee, Pap, that's..."

"It's going to be GREAT!" Papyrus gushed. "I've been asking Undyne for weeks about taking it, but she kept getting...weird about me patrolling alone. BUT, with the two of us, we can team up against any human that comes into Snowdin!" He bounced down onto the edge of the sofa, giddy with excitement. "And this way everyone's happy! You won't be bored, and I'll be closer to being in the Royal Guard!"

"Heh..." Well, this was...sweet. Sans sat up and pinned the badge to his hoodie. "You know, you're right. With both of us, snowbody's gonna get through to the rest of the Underground."

"Don't you..."

"What? I'm just saying icy what you mean."

"Sans! You're ruining things again!"

"I have no idea what the hail you're talking about!" He chuckled as Papyrus promptly jumped up and started stomping away. "Hey, Papyrus, hang on!"

"I'm not speaking to you!"

"Thanks."

Papyrus turned around, and Sans...well, he couldn't smile, but he looked at his brother warmly. "This really helps. I'm...I'm glad I've got you looking out for me."

Papyrus gave Sans a big smile. "Of course, brother!" He went quiet, browbone furrowed. "You could say...I've got your backbone."

Sans blinked, and his whole face brightened. "My god, Papyrus, you just made my whole day." "Don't expect it again! I, the Great Papyrus, do not stoop to puns for entertainment." He bounced in place as he saw Sans get up. "Are you going to patrol right now? That's the spirit!"

Sans shook his head. "Nah, I've gotta go figure out my break schedule," he said with a wink. "Be back in a while." He headed out the door, then took a breath. He almost teleported, but decided he needed the time to think. If he was gonna move on past...what had happened, he needed to clear the air. The group should be meeting about now.

He reached the lab and stared at the door for nearly two minutes. He had to do it. Even if he wasn't going to reset again, he still needed to figure out what was happening with this thing no one could remember. Maybe it was like what had happened to...well, whatever her name was.

He took a step forward, and the lab's doors hissed open. He frowned as he walked in; it was awfully dark. And far too quiet. He took cautious steps inside, looking around. "Gaster?" he called. "Hey, Gaster?" Had something happened to him? Sans felt something in him twist. Oh, god, what if he had reset and disappeared? No, he wouldn't remember Gaster if that was the case. But...what if that thing that had killed Papyrus...?

"Gaster?"

"Sans?"

He hadn't heard the door to the lower lab open, but regardless, Gaster stood in front of it, lit from behind by the elevator's light. Sans let out the breath he'd been holding. The old man was all right. Good.

"Why are you standing in the dark?" Gaster turned and flicked on a switch, lighting up the lab.

"I, uh, well, I didn't know...wait. Shouldn't the group be here now?"

Gaster looked at him for a moment, then sighed. "Ah. Yes, I had forgotten." He gestured to the empty lab. "This is all there is."

Sans's brow furrowed. "What do you mean?"

The scientist's shoulder sagged. "I mean they are gone. One day, I sat waiting, but...well, nobody came."

Sans' sockets widened. "What? All of them? I mean, there were...there were, uh..." His face went blank. How many researchers had there been left? How many had there been to begin with? "Oh, god."

Gaster had walked over to his desk and pulled out a photo, the same one from Sans' last time in the lab. "Eight," he said quietly. "There were eight." He sighed and shook his head. "All I seem to create are catastrophic failures."

Sans blinked quickly. "But...the resets..."

"It is clearly too dangerous to pursue further research." Gaster put the photo into his lab coat's pocket, then rubbed his skull. "When we last spoke...you were right," he said softly, then gave a bitter laugh. "Your title is far more apt than I had realized."

Sans shook his head. "We...we can't just leave it there, though! The thing that was causing all the first batch of resets is still out there! If we can figure out what it is, we can..."

"Sans. It is over. I will not put anyone else in harm's way," Gaster said firmly. He glanced up, catching the pained look on the other skeleton's face. He shook his head with a huff. "If I have any other ideas concerning resets, I will contact you. But for now..." He looked down at the floor. "For now, please spend time with your brother. He needs you far more than an old madman does." He looked up at Sans for a moment, then gave him a curt nod of dismissal. "It was...more than pleasant to work with you." He looked up, and his hands added, "And I wish you nothing but the best." Just as Sans raised his hands to sign back, Gaster quickly headed back to the elevator, door closing before Sans could sign even one word.

~

Surprisingly, the monotony of patrolling Snowdin seemed to be just what the doctor ordered. After all the stress of the resets, the loss, the fight with Gaster, a few months of walking around what had to be the least intimidating town in the Underground with Papyrus was, honestly, the best job he'd ever had. Sure, getting from the Core all the way to Snowdin was a pain; he and Papyrus always went together, and while the occasional teleport with a plus-one was fine, a whole week left him completely drained. Walking was the better, if more boring, option. But hey, Papyrus was having the time of his life. Plus Grillby's was right smack in the middle of town. No one went with him now, but he managed to get friendly with a few of the other sentries. It almost made him feel like a regular guy. Things were good.

Even so, he'd be lying if he said that he wasn't a little excited when he saw the letter in his mailbox on his day off.

He recognized the symbols scrawled on the paper the moment he opened the envelope. To his surprise, he didn't even hesitate to translate them. Maybe the few months in Snowdin really had helped him cool down. His sockets widened as he finished the translation.

COME TO SNOWDIN IMMEDIATELY. WE ARE MAKING HISTORY. –G.

Well.

How could he turn down an invitation like that?