We're back at this place again.

Mouse hole. Steaming cup of coffee. The bottle of ketchup, still full and protruding awkwardly in your pocket. The blanket wrapped around your shivering shoulders.

I'm back to being stuck behind the looking-glass to your body. What'd you do? You got scared that I wouldn't let go? Or you stopped having fun when the second skeleton died. It's the same thing. It's not like it's okay to kill one and not the other. They both caused pain. They both stuck me in this miserable situation.

You're an idiot, coming back here when you know what will happen if you don't kill Gaster. And you can't kill Gaster, not without me. So where does that leave you? Victim or killer. Take your pick. It's not like I can feel pain.

You throw the blanket onto the ground. You leave the room and don't take the knife.

Whatever you think you can accomplish, you have precious few minutes before Gaster finds you and drags you off.

You move without hesitation, pretending that you have some kind of plan. The first door you check is one you've been to in the past. It's the room with the strange machine, and the Sans skeleton. This time you step inside, closing the door behind you.

Really? The last thing you saw was the knife breaking his bones, and your first instinct is to go find someone you murdered?

He hasn't noticed you yet; he's too busy working under the insides of the machine. You try to wait, patiently, but you're not sure what your time limit is before Gaster finds you. Would Sans abandon you like Alphys? He might be convinced you're 'dangerous'. Well, you let him get murdered him in another lifetime, so it's not like you don't deserve it.

You rap lightly on the side of the machine, the metal making a strange clank.

Sans rolls out from beneath the device, his back on a skateboard. His eyes widen when he sees you waiting there. But, he's not on guard; doesn't look ready to initiate fight or flight. The events that happened moments ago, so fresh in your mind, have never happened in his perspective.

"hey there." He's just surprised that you've come here, alone, to see him. "uh, what's up? where'd alphs go?"

You lock your hands behind your back, your mind not computing any words, as he stands and waits for you. Well, so now what? What are you going to say to him? 'Hello, I've recently been time traveling, and so far I've either died or killed you.' That'll go over great.

The silence has stretched on for an uncomfortable time. Sans is smiling, but he's probably annoyed by you, since you interrupted his work for seemingly no reason.

"i'll be done soon," he promises, stuffing his hands in his pockets. "go back and i'll be right there before you know it, ok?"

You're failing. If you're lucky and fast, you might have enough time to go back and grab that knife...

You shake your head. "Help," you utter. Just loud enough to hear. "...Please."

There's a thin line of sweat across his forehead. It's the second time you've ever spoken to him, and now you're asking for help. You're probably freaking him out.

"help you? with what?" He's heard you, but he doesn't understand.

Only a few seconds pass before a light flashes beneath his pockets, with a sharp chirp. He flips open his phone, reading the text message. His brow furrows even further.

"...it's from doctor gaster. he... can't find you, was wondering if you're with me," he looks up to you slowly.

Your heart has started pounding, even if you remain expressionless. You're still wondering if he'll just leave you, like Alphys.

"is this what you need help with?" His gaze looks through you critically, seeming to know. Previously, Gaster had said he knew that you might reverse time. If he knew that was a possibility, then Sans likely knows it too.

You nod decisively. Leaving your fate in his hands. Indirectly admitting your time-travel, or at least incriminating yourself.

"wow." Sans takes a deep breath. "ok. let's go see him then, kid." He moves to the door.

You remain rooted to your spot. Because, just like Alphys, Sans will do whatever Gaster wants. He just admitted it. He's going to take you to him, because Gaster couldn't find you. He'll probably ask him to go easy on you something, but he's still taking you there first, instead of hiding you away.

He's already at the door by the time he realizes you aren't following. He turns back to you. "uh, you ok? you coming?"

Slowly, you shake your head. "No," you whimper.

"hey, whoa, you're not tearing up on me, are you?" He's back to being alarmed so quickly. "aw, geez, i - i mean, i can only guess what you're thinking. but my bro's not going to hurt you. i won't let him," he promises, and you look up at that, daring to hope again. "but, we gotta talk to him. i'll handle the hard stuff, but you need to show him that you're a real person, too. i know you're scared, and i know he's hurt you, but he's not a bad person. trust me; he's my bro. sometimes people seem scary when you don't understand them... but as long as they feel even a hint of compassion, it means there's still good left in them." He extends his boney hand towards you, as if offering an invitation. "ok?"

You hesitate for a moment. You would prefer never to see Gaster again, if possible. But Sans has promised to be your voice. The real question... do you trust him more than me?

It takes you a few seconds before you nod, accepting his invitation. He waits patiently for you and you accept his hand. It's hard to tell whether he's happy or not when he's always smiling.

Well, you've made your choice. Whatever happens is your fault now.

He leads you through the laboratory. You try not to wince as you near the cursed room where you last killed the two skeletons. You're not sure if you have any good memories of that place. Thankfully you two just pass it, and you're on a path you've never been on before, until you reach stairs. You're strong enough to take them yourself, but he holds onto you firmly... either to catch you if you slip, or to prevent you from escaping.

The room has some kind of machine, like a super computer, in front. The far wall is pure glass. You recognize the room behind the glass – it's the one that Gaster likes taking you to. Where I first woke up. You're on the other side of the looking-glass this time: the observatory room. Gaster stands at the super computer. Your limbs stiffen; Sans squeezes your hand encouragingly, offering you a placating smile.

Gaster is alive and well, like nothing ever happened. Because it didn't. The issue of repeating time he was so worried about... if not for that power, he'd be dead. He turns as the two of you approach, and you can tell. The calm facade you last cracked, he's still pretending it's there. He doesn't remember. You could do anything, and there's no consequence unless you want it to stick. You get to pick which reality stays, and which isn't worth it.

Alphys is there, too. She's biting her claws. Maybe she was always here, even in the other timelines. That's why she appeared when you were being dragged to that machine. Maybe she even saw you murder Gaster, but was too scared to stop it herself, and got Sans to enter the room instead.

"Sans," Gaster breaks the silence first. "I know what you're thinking. But we picked up some strange determination wavelengths today. We need to know if the doll can reset time."

"why are you talking to me about it? you should ask them," he nudges you. "you don't want to go back in that thing, right, buddy?"

Your throat clenches, as you feel all their gazes upon you. But it's a yes or no question. You don't need to speak. Silently, you shake your head, but can't look at any of them.

"It's dangerous, Sans," Gaster disapproves. He's still talking to his brother, even at Sans's request to address you. He doesn't need to convince you. He just needs to get Sans to give up. "Human souls can persist after death. That human soul was absorbed by a monster. And when that monster died, the soul STILL did not disappear."

"Its will made the soul practically immortal. Combined with a vessel originally intended to traverse time... we don't fully understand the results. In a worst case scenario, it's already manipulating time to create a reality that wouldn't normally exist."

I like this. It makes me sound like God.

"then we shouldn't put them in a situation where they want to change reality," Sans still tries to argue, on your behalf. "the harder you push, doc... you're just going to break something, eventually."

"We have to have some way of knowing if they've messed with time," Gaster says curtly. Neither seems willing to give up or even listen.

"there's one other way. a theory that you were talking about a few days back. the possibility that a monster's soul could act as a vessel for time travel, with enough injected determination. "

For the first time, Gaster doesn't have an immediate response. The silence feels strange. You're not sure you understand all their technical talk.

"That's an untested theory," Gaster finally says. "Monster souls don't have the same durability as a human's. It might work if it survived, but the odds of the monster's soul disintegrating under the pressure..."

"yeah, but if it doesn't, it should retain the same or similar properties, right?"

"S-Sans, what are you saying?!" Alphys blurts out, unable to continue her silence.

Sans sighs. "i'm saying you just need a volunteer. i'm volunteering."

"You'll turn into dust!" Alphys is so upset she doesn't even stammer.

You might not understand everything. But you know that Sans just offered to risk his life. It surprises you, too. It's such the opposite of Alphys. Does he really care about you that much? When no one else seems to think you're alive?

"Absolutely not," Gaster refuses instantly. He was so quick to offer you up, that you expected him to consider Sans's idea. But he doesn't. "The risk is far too great."

"hehe, they're risking their life every time they're in that thing, doc. why should we expect them to do that, when we won't do the same?"

"It's not the same!" Gaster's boney fist clenches. He's actually upset. "It's not alive, Sans. You are."

"c'mon, doc," Sans shrugs. "you and i both know this needed to be tested eventually. now just seems like the best time to do it. and who else would willingly walk into such a test, huh? it's not like there'll be more methods that make it safer over time."

"We don't know that," Gaster grumbles. He turns away, facing the glass paned wall. "...Alphys, go help Sans set everything up in there. If he wants to do it so badly, I won't refuse."

"Wh-what?!" Alphys jumps. "B-but-"

"DO IT," Gaster cuts her off, and she scurries out of the room so fast that she nearly trips.

You stare at Sans. He's really going to do this. He's going to risk his life, and his coworkers are willing to do it. What kind of messed up place is this? What did you do to deserve this; to deserve his kindness? There's something wrong with all of them.

"it'll be ok," he promises you, still smiling. He never stops smiling, even when you think he's not okay. He wraps his arms around you in an embrace. You don't understand; your arms limp beside you. "just remember... someone out there really cares for you."

He finally releases you. Gaster still has his back to you. "thanks, bro," Sans says. And then he's gone, following in Alphys's footsteps.

It's only when he's gone that Gaster turns back to you. He puts his hand on your shoulder, so tall that he nearly has to bend over to do so. "You must like my brother a lot. It's not hard to guess that you time traveled and asked him to help. And now, he's risking his life for you." he whispers. It sounds like an accusation instead of something touching. His hand tightens around your shoulder. "Remember that. Because if something goes wrong... I'm counting on you."

He glares into your soulless gaze as if he can summon my soul to the surface. You don't answer. He turns back to the glass.

Alphys is running out of the room below. You can't hear the whirring of the machine, not from this room, as you watch it descend. Only a pair of sneakers are visible by the time it's completely gone down. Sans has taken your place.

Alphys returns to you and Gaster in just a few seconds. "O-okay. It's set," she's breathing heavily, from nerves or from running up a flight of stairs, or both.

"Do it."

You can't tell anything at first. You're watching a silent movie, a skull-like machine throbbing faintly.

...Then you notice your ketchup bottle has escaped from your pocket. It floats up slowly, as if somehow attracted to the ceiling. Your body starts to feel lighter; your hair literally stands up on its ends.

"Alphys?" Gaster turns to the lizard, as if in slow-motion. Your silent film has turned into an astronaut movie. Gravity refuses to listen, pulling at your legs, trying to remove you from the floor...

"Um, th-these r-readings, I don't-"

"TURN IT OFF!" Gaster screams.

Alphys slams her fist against the computer.

Instantly gravity stops. The ketchup bottle falls to the ground, clattering from the abrupt fall, cracking and leaking ketchup. You fall on your side; the other two as well. Except Gaster has found his feet immediately. He's already running down the stairs.

"Sans!" He shouts.

It's going wrong.

On your side, you can still see through the glass window. You can still see a pair of sneakers beneath that machine.

He's dead.

You're certain of it.

Time has something against him.

No matter which timeline you visit, he's going to die. It's history and the future. Even if you go back, he'll probably just die again.

Gaster has reached the room. He's struggling with the machine, actually trying to pry it with his bare hands; completely forgetting how his own device works.

If that thing goes up and there's just a pile of dust...

You don't think you could take it.

Notes:

Sorry, took a little longer than normal (and on a cliffhanger), hope you enjoy this longer chapter (for me) as payment! I might be slowing down a bit in the future, not that I exactly had a consistent schedule.