Disclaimer: I do not own Percy Jackson, Heroes of Olympus or Undertale. Percy Jackson and Heroes of Olympus is owned by Rick Riordan, and Undertale is owned by Toby Fox.

I only own this story.

Chapter 1: Introduction

Sans POV

i'm pretty damn depressed. how many resets have passed? 50? 100? i'm not sure. frisk has just finished yet another pacifist ending, and everybody is acting all happy and whatnot. little do they know that the kid is just gonna reset, like they always do. i suppose I can always hold out some hope, maybe the kid will choose to just continue from this point rather then resetting. due to some sort of anomaly in our current timeline, asriel, gaster and chara have managed to return, along with the knowledge of frisk's resets and what she's done, but they keep quiet about that. which i'm grateful for, because I don't wanna hear the kiddo talk about their determination and the resets they've gone through.

Hopefully the kid decides to not reset for on-

"SANS!"

i turn my head to see an angry undyne staring at me. wonder what she's mad about, though. maybe alphys watched an anime without her.

"Sans, why are you sitting here just lazing around! We need to move our stuff to the town we found at the bottom of the mountain, so why can't you put your teleporting powers to use and get the stuff from your house here!"

oh. so that's what she's mad about.

"come on undyne, i've told told ya that teleporting takes a skele-ton of work."

"GAH! STOP IT WITH YOUR PUNS, SANS! If you're too lazy to teleport, then just carry the boxes here, or teleport Papyrus there to get the stuff! Don't just sit here and-"

"Undyne?"

frisk is standing right behind undyne, with her usual unreadable expresssion. wonder why she's here.

"Can I talk to Sans for a second?"

undyne looks a little confused as to why the kid would wanna talk to me, but she lets it go.

"Alright Frisk. But only since you're my friend. But I'll be back, Sans!"she says, then she walks away.

i turn to frisk. "so kiddo, whaddaya want to talk to me about?"

"I won't reset again."

i stand there for a moment, then break the silence.

"kiddo, don't lie. you're just gonna get bored, then reset again."

"I promise I won't-"

"kid. if you got bored enough to commit genocide...then i don't have a gurantee as to what you're gonna do. you've reset more times then I can count... and that's saying somethin'."

"I promise I won't. This current timeline...is precious. They're back,"she says, pointing at asriel, gaster and chara. "I'm not going to throw this away."

i look at the kid for a bit, thinking, then come to a decision.

"fine kid. i'll play your little game, but i'm not convinced that you won't reset again. now run along with the others, i'm gonna have a talk with ol' dings."

and with that, I trudge off.

Percy POV

My day was going pretty well. I've been training at camp, visiting my mom and Paul, and hanging out with my girlfriend Annabeth, along with some other friends. Nothing could go wrong, right?

I was wrong once again.

At that precise moment, the horn was blown to call all campers to the dining pavilion. When I got there, I saw Chiron in centaur form, standing at the Head Table, along with Zeus, who I was surprised to see.

"Campers!" He bellowed. "Lord Zeus would like to assign a quest to a select group of demigods."

"Will Percy Jackson, Annabeth Chase, Nico di Angelo, Jason Grace, Piper McLean, Frank Zhang and Hazel Levesque please proceed to the front?" Zeus asked.

Me and the others stepped forward, a little afraid as to what this quest might be.

"I have sensed hundreds of magical energy signatures descending from a mountain called Mt. Ebbot. Some seem rather weak, but others rather powerful. I want you seven to find out who-or what those energy signatures belong to, and to destroy them. Understood?"

My friends nodded, but I had one question.

"Um, Uncle, if you don't mind me asking, how come you are assigning this quest? Isn't the oracle supposed to do that?"

"Under normal circumstances, yes. But your oracle has not delivered a prophecy yet, and I would like this matter to be resolved quickly. Even the Fates have allowed this. So-"

Zeus was cut off by Rachel slumping over for a moment, then rising back up with a green mist surrounding her. She spoke with a voice which did not sound human:

Seven travel far to meet monsters unknown,

Sealed by the gods so they would not be shown.

Their power rivals the strength of the gods

Despite each possessing a number of flaws

The earth can shake with the strength of each

Putting recovery of Olympus out of reach.

We all stood in shocked silence, comprehending the prophecy which was just issued.

Zeus decided to break the silence, and said "Well, that works. I still propose that you destroy the creatures there. Putting recovery of Olympus out of reach-I would rather that dosent happen."

"The earth can shake with the power of each,"I said. "That implies that it's not definitely going to happen."

"Yet it also means they are capable of it. I shall not take any chances. These monsters are dangerous.

So, demigods, considering your past accomplishments, I trust you will be able to solve this issue. Since the Fates have unusually allowed me to help you a little, I shall teleport you seven to Mt. Ebbot. Good Luck."

With that, Zeus snapped his fingers, and the world turned upside down.

When we woke, we were lying at the bottom of a hill. We also heard some commotion over the other side of said hill, but that seemed rather insignificant due to the fact that we were all feeling dizzy and disoriented from the teleportation.

"Jeez, I wish that teleportation thing was less disorienting," groaned Piper.

"Well, I don't think Zeus had our ability to focus after the teleportation in mind," Frank grumbled.

"Those monsters look...interesting," said Annabeth, who was peeking over the edge of the hill. "I wonder what they can do. They don't really seem too threatening."

Jason leaped to his feet, apparently unfazed by his father's teleportation.

"Doesn't matter, there's no time to waste. Let's go slash some monsters, just like old times,"he said grinning as he drew an Imperial Gold sword. The other demigods got up and drew their weapons. They then took a deep breath, and then sprinted down the hill.

Gaster POV

I smiled as I looked out at the sun. During my time in the underground, before my failed experiment... I had dreamed of seeing the sun. But my experiments which were dedicated to destroying the barrier failed...but we're all here now. That was all I had wished for, and I finally got it.

"hey, dings."

I turned to see none other then Sans the Skeleton walking toward me, with his infamous grin.

"Hello, Sans. Is there something you would like to talk to me about?"I asked.

"well, yeah actually. i wanted to ask ya about determination. from what I can understand, you experimented with injecting yourself with determination you recovered from the fallen humans. do you think you would be able to reset?"

"Well...I'm not sure. Monsters can't have determination."

"then how do ya explain undyne? you've seen what the kid has done, and the paths they've walked, watchin' em from the void. ya know undyne has used determination to give herself what was essentially another life in genocide routes. what if we could muster up the determination to reset ourselves? or load files ourselves? or just achieve determination that overpowers the kiddo, so we can control the timelines ourselves.

"Sans, that's a dangerous thought. But if I had to guess, even if we could get determination, we probably wouldn't be able to manipulate time like the Frisk and Chara anyway. Their souls are still human, and still more powerful then ours, so I doubt it would be possible-"

I stopped abruptly, catching in to sounds of a violent fight going on in the town we had chosen to settle in.

"wanna stop what's goin' on there?"

I swallowed down my fear. From the sounds of it, the fight was pretty bad, and I had only just started getting used to my magic again, but I needed to help.

"Yeah," I swallowed. "Let's go."

Anddd the first chapter is done! Put a lot in f effort into this, so I hope you all like it. Just as a little FYI to those of you not familiar with Undertale, All of Sans' talking and thinking is in lowercase because his font, comic sans, dosent have uppercases. So yeah. Anyways, hope you enjoyed!

-Random Potato Kid