Limits of Determination

By Ulrich362

(Author's Note: I do not own Undertale)

In a long hallway littered with slash markings, and broken bones two figures stood opposite each other. One, a young dust-covered girl in a purple and blue striped shirt wearing a heart-shaped locket and holding a knife in her hand, the other a Skeleton in a blue jacket with his left eye glowing blue. The two of them stood silently, breathing carefully as they waited for the other to make the next move in this fight to the death.

"Why did you go through with it kid, they didn't deserve any of this." the skeleton noted coldly. "The voice behind that door, Undyne, even Paps. What could possibly make you think doing something like that was ok?"

"You don't understand Sans." the girl repeated for the hundredth time since they'd started their fight.

"At least we agree about that." Sans mentioned. "There's no way I could ever understand why someone would commit genocide on an entire innocent race. You had so many chances too; I feel them, the Resets. Every single time you die you just come back and keep going forward, it doesn't matter who got in your way you'd just keep trying until they were dead."

"Sans, that's not…" the girl argued. "I didn't have any choice!"

"Yeah you did, you had so many chances to reset, and you didn't even have to go that far. Just choose to spare someone, prove that you aren't completely evil." Sans countered. "You chose to kill them all, or are you suggesting that someone else moved your hands and made you do it?"

"No, there wasn't anyone forcing me to kill everyone." the girl admitted.

"Then it sounds to me like you did have a choice, and you chose to kill everyone." Sans concluded. "To think I once thought we could be friends, I guess I was wrong about that."

"It isn't that simple Sans, I'm telling the truth I had no other choice but to do this!" the girl explained as her hands started shaking.

"Let me guess, it's because of your Determination isn't it?" Sans questioned. "You set your mind to this and once you did there was no stopping you. You're even going to kill me before you're done aren't you?"

"I…" the girl started.

"Save it kid, I know that it doesn't matter how many times I kill you." Sans interrupted "Sooner or later you're just going to kill me instead so…"

"I did this to save you all!" the girl yelled. "Sans I killed everyone in the Underground, looked desperately for every monster I could find just so there could be a slim chance of saving you all."

"What? What are you talking about, how could you possibly save us by committing a genocide?" Sans questioned as his eye began glowing even more intensely.

"Sans, we've made it before." the girl mentioned. "We've been to the surface, more times than I can count."

"We've…" Sans started in disbelief. "So not only did you kill everyone, but you've torn our freedom from us countless times."

"No, I didn't." the girl said. "When we get there, someone or something, it forces the world to reset. I can't stop it, I've tried Sans and I even managed to keep us there for a few days but eventually it happens again."

"Alright, let's say I believe you." Sans noted. "That still doesn't explain why you would think that this is a better alternative."

"It's because we need more Determination." the girl explained. "There are still two other people with as much Determination as me, Asriel and Chara."

"Asriel, you mean the prince who fell?" Sans questioned. "He's dead, and I've never heard of anyone named Chara."

"Asriel isn't dead, or at least he isn't anymore." the girl mentioned. "He's Flowey, his dust was revived with pure Determination."

"Alright, and who's Chara?" Sans asked as his eye stopped glowing.

"She's the first human who fell down here, she's been guiding me through the Underground, and when I reach the end and the barrier is about to break she sacrifices her life to save mine." the girl answered. "If the three of us could all work together, you and Dr. Alphys said we might be able to stop the Resets for good."

"That still doesn't explain why you'd need to go this far." Sans pointed out.

"It was your idea Sans, it's the only way." the girl replied before looking down.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

"What's up Frisk, you wanted to talk about something?" Sans inquired.

"He's right Frisk, is something wrong?" asked a yellow lizard monster in a lab coat.

"Sans, Alphys, it's going to Reset again." Frisk admitted. "I don't know when, or how but something's going to force the world to reset and there's nothing I can do to stop it."

"What are you talking about kid, you're the only one with that power and you wouldn't reset this, would you?" Sans asked.

"Of course not, but this isn't the first time it's happened." Frisk explained. "The first time, I thought I'd done it by mistake and worked to free us again. Though then it kept happening."

"How many times has it happened Frisk?" Alphys inquired nervously.

"I don't know, I stopped counting after the tenth Reset." Frisk admitted. "I don't know what to do, I could save everyone and even convince Asriel to break the barrier but this…"

"Oh yeah, that's right. You told us about what happened to break the barrier." Alphys noted. "It's just, how did you survive that attack?"

"It was Chara, she gave her life to help me save all of you." Frisk answered.

"Heh, so that's what happened." Sans stated thoughtfully. "The first human's soul bonded to you and when you reached the end of your journey she sacrificed herself to set us monsters free. That sounds like she had almost as much Determination as you."

"That's true, what are you thinking Sans?" Alphys questioned.

"If Chara dies saving Frisk in one timeline, maybe there's one where she doesn't." Sans replied. "I might be able to bring her to the timeline after this Reset and…"

"Do you really think that could work?" Frisk asked hopefully.

"Well in theory it is possible but…" Alphys started.

"What is it Alphys?" Sans prompted.

"Frisk how far back can you reset?" Alphys inquired.

"I can go to the moment I fell into the Underground." Frisk answered. "Is there something wrong?"

"Chara would have already been dead by then, which means…" Alphys started.

"What does it mean Alphys?" Sans questioned nervously.

"The only way for Chara to be brought back would be for Frisk to gain massive amounts of LOVE." Alphys finished. "She'd need to kill every living soul in the Underground."

"What, but there's no way…" Frisk started. "I could never kill you guys."

"You wouldn't have to just kill us once kid, if everything resets you'll be the only one that remembers any of this." Sans noted. "You'd need to force me to fight you, so we could get to different timelines in the first place, but if you do that…"

The moment Sans said that Frisk collapsed to her knees.

"No, you don't mean…" Frisk started.

"It's the only way kid, it'll hurt and if there was anything I could do to make it easier on you I would but…" Sans admitted.

"Do you think it would work?" Frisk asked quietly.

"I don't know, but it's the only chance we have." Sans answered. "So for now, let's enjoy what little time we've got left."

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

"So that's it, you did all of this so we could Reset again and get you, Chara, and Asriel together." Sans summarized. "Though if you don't mind me asking, just what was it that I meant?"

As those words left Sans mouth Frisk started crying as the knife fell out of her hand.

"Sans, I… I…" Frisk choked out weakly.

"You what kid, what is it that you would have to do?" Sans repeated. "You've already come this far, there's nothing that could… Wait, you aren't saying what I think you are?"

"It was so… hard to do it once." Frisk sobbed as tears started flowing down her face. "Mom, Papyrus, Undyne, I just…"

"Kid, if you want to save everyone in the underground you're telling me not only did you have to go through all of this just to tell me, but now to bring Chara back you'll have to do it again?" Sans questioned. "You need to commit a second genocide?"

As soon as those words left Sans mouth, Frisk buried her face in her hands and started crying as she fell to her knees.

"I'm so sorry, I never wanted…" Frisk started before starting to cry again.

This kid, you can't fake that kind of guilt and pain, Sans thought. Alright, there's no way of knowing if this crazy plan will work but it's apparently the only one we could think of. "Kid, I just have one question. If this whole thing works and it never resets again you'll stop too right?"

"I promise, I just want…" Frisk started as Sans walked up to her only for a bone to suddenly stab through both of them.

"That's all I wanted to hear pal, let's save everyone together." Sans said quietly.

"Thank you." Frisk said quietly as the two of them disappeared from the hall.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

"What the, where are we?" Sans questioned looking around at the empty black space he and Frisk had suddenly appeared in.

"This is where it happens, whenever I die I end up here and can make a choice." Frisk explained as two glowing yellow buttons appeared in front of them. "I could continue from where I died, and keep moving forward, or I could Reset to the beginning and try again."

"Alright, then I just need to travel through the void while you Reset." Sans noted. "Then, I need to kill them all."

"What?" Frisk asked in shock. "Sans what are you…"

"You already went through that kind of torture once." Sans explained. "I can't say it'll be easy for me either, but nobody should have to go through something like that even once. You've suffered enough kid, re-make friends and make sure the Barrier is broken and we all stay on the surface this time."

"Sans…" Frisk started before wiping tears out of her eyes. "Right, I'll make sure of it."

"Alright, well here goes nothing." Sans mentioned as he let the Void envelop him while Frisk hit the Reset button and everything faded in a white flash of light.

(Frisk has saved monsterkind from the Underground countless times, but a mysterious force has Reset each and every time, but now Sans and Frisk are attempting a desperate plan to try and stop the resets for good, but to do that Sans will have to kill all of his friends. Next chapter, Sans will arrive in a new timeline and he'll start getting blood on his hands. As always any reviews or critique is appreciated.)