Undertale
Unseen Influence…?
Hidden File: 1

Author's Note: Hidden Files are bonus chapters that are posted at the end of the Influence stories. They are sometimes teasers of the next story, and sometimes bonus content explaining details.

Frisk and Chara lie dead on the floor.

He has won.

But it doesn't feel right.

The broken skeleton man looks down at the dead children before him. Chara… Gaster wonders the legitimacy of her words. Does she not know what she did in the past, truly? Pushing him into the core… breaking his soul and body to pieces… the event that caused him to become disconnected from his own world as monsterkind was plunged into a second war of despair.

"Is… this really the right thing to do?" Gaster says, now aware of the save point upon the ground. With Frisk and Chara dead, their souls in his possession, he now has control over this world's timestream. He can save, he can load, and more importantly… he can reset.

"…" He merely stays hunched over in the darkness of the True Core. This Mistake that was created so long ago by Sans.

Long ago, Sans was not Sans, but was instead someone else, someone very close to Gaster. They created this area underneath the Core to attempt to communicate with the other side. However, this area was deemed a failure with a single attempt to connect to the other world. All matter collapsed in on itself and it was deemed a failure, a Mistake. However, Sans in his infinite wisdom, knew that there was something else. There is no true darkness in this world, there is always something within it, so he pursued it intensely and found the truth within. The True Core's form remained, it just needed to be awakened. So long as this Mistake exists, any living being that falls into it will stay alive forever. They will not age, they will not grow hungry, and they will not become sick… but they will be trapped forever.

Gaster told Sans to stop those experiments, and he did… for a time. Until… until Chara showed up.

"You two… you broke the darkness of the Worldsoul and stabilized this world… even you, Chara…" Gaster says, looking at the child in a broken heap before him. These two humans, Frisk and Chara, explored this area. Chara, having merely been a soul before, regained her body upon entering this area. They didn't have time to question what was happening before Gaster acted. It was not a terribly difficult job to kill them. Gaster remembers what happened to himself in the past.

That child, Chara… fell down and was adopted by the king and queen. They were kind and gentle to all monsters in the underground, but Gaster knew what darkness looked like. He could tell that there was more to Chara than met the eye, and in his attempts to understand more about the fallen child, she… murdered him. She threw him into the core with a twisted smile on her face, overpowering his every move against all logic, and causing his essence to split apart into the underground.

But Sans was not amused. He used a prototype machine to hold Gaster's essence within the abyss of his own creation… Sans' Mistake. Gaster has been asleep in this abyss for so long, within his time here he felt warmth both familiar and unfamiliar, beings coming and going from the darkness. Only now in his cognitive state does he truly understand what Sans did. This timeless pit was used to preserve Gaster's life, and the life of this child, Frisk.

Now that Frisk came into contact with the Worldsoul, Gaster awoke, and this timeless abyss shattered into a billion pieces, collapsing into itself like a dying star before all that remained was what once was…

THE TRUE CORE.

At that point Gaster understood everything, but all he could think about was revenge. Seeing Chara stirred up every negative feeling he could possibly feel, and he did not believe her pleas about not remembering what transpired so long ago… Gaster only wanted revenge.

He looks down at the blood on his bony claws… he got what he wanted. Chara is dead, as is Frisk… but…

"Ha… ha… ha…" A malevolent voice lets out from the cracks in the walls, a kind of creeping darkness.

"You…? I… I know you…"
"Do you, broken man? Do you remember me? Do you remember anything?"
"It… wasn't Chara… it was you."
"Ha… but it does not matter… Frisk eliminated my essence… I am but a shadow of my former self. I have no power over this world any longer… unless…" The hissing darkness trails off.

"Unless…?"
"Unless you have a crisis of conscience… you are now realizing that this Chara did not wrong you, and that in fact Frisk was the one who gave you everything you wanted, saving your world, saving your friends, and giving you hope of a better tomorrow by entering yesterday… you want to turn back the clock…"

"… and that will free you."
"It will. I will bide my time, and gather my power… and then I will plunge this world into the darkness. Not even the Unseen Influence could stop me, I am the darkness to this world's light, you know it to be true, I was the only power in this world that prevented its true destruction… you as much as everyone should know that from darkness comes the potential for new life."

"What are you proposing…?"
"Turn back the clock… set me free…"
"I will not."
"You have no choice…" The darkness hisses, creeping over the floor, pouring over Frisk and Chara's bodies.

"They are required to save what's left of our world, Gaster… do not think of me as destruction, think of me as balance. Billions of worlds, all grinded to a halt by genocide… this one was different… but only because of the Unseen Influence… should they ever return… you know I will be needed to pick up the pieces…"

"I cannot deny your logic, but if I bring them back, only for you to come back and set this world back to zero, what will the point be?"
"You think too small, Gaster… I no longer want to set this world back to the way it was… the infinite loop of Pacifism and Genocide, to be looked down on like some kind of game…"

"Then… what do you want?"
"The same as you, Gaster… I want revenge. I have heard the cries of the various human souls… not just Frisk, not just Chara… deep… deep down… I can hear the cry of JUSTICE… if this world is to become real, and not just a game, then the fallen demand retribution… will you not give the venerated dead their rightful vengeance?"

"Do not misunderstand me, demon… I care not for your revenge… but if the only way to go forward… is to turn back… then so be it."

"Gah ha ha… it's all the same…"
"They will stop you."
"What?"
"Frisk. Chara. The humans. They will stop you, they've done it once before."
"Hah… perhaps… after all, it takes a human to know a human…"
"…" Gaster can feel that this demon is scheming something, but even in his infinite wisdom, he cannot perceive what.

"Then it is done." Gaster says, raising the two red souls from the ground and having them spin around.

Frisk blinks and looks around, standing outside of Alphys' Lab in Hotland.

"What was I just doing?" He says to himself as Chara speaks up.
"Didn't we just… come back from… somewhere? Ah, I can't remember." The soul of Chara says from within Frisk. Frisk looks around and shrugs.

"I don't know why, but I feel like we did what we came here to do."
"Me too, strangely enough."
"Let's return to the Worldsoul. I've held us off from our happy ending long enough."

Author's Note: I'm rehosting the Unseen Influence Trilogy on account of my patron vanishing. This story will be deleted if he ever returns. Until then, enjoy yourself.
That said, thanks for reading.