"Long ago, two races ruled over Earth, Humans and Monsters."
"One day, war broke out between the two races."
"After a long war, the humans were victorious."
"They sealed the monsters underground with a magic spell."
[Mt. Ebott 201X]
"Legends say that those who climb the mountain never return."
"Six humans fell into the underground, each human different from each other, yet all of them met the same fate."
"The King of the Underground, King Asgore, needed seven human souls, and with those souls he will become a GOD and can destroy the barrier that has kept the monsters trapped underground for ages."
"King Asgore has collected six human souls thus far."
"Finally, a human, filled with DETERMINATION, fell into the underground."
"They passed through the Underground, showing MERCY to every monster, no matter what the monster has done to them."
"The human, having completed their journey, went to the barrier to leave the underground."
"Somehow, the human broke the barrier and freed the monsters, but the human souls that were collected have disappeared."
"It is still unknown how the barrier was destroyed, and the human refuses to tell anyone."
"The monsters now live happily on the surface. The humans have learned to adjust to the sight of monsters, but it will take some time before they accept the monsters into society completely."
"The human made many friends in the Underground and lives with them in Ebott City."
"Everyone is now happy, their souls filled with joy. The human saved the monsters from the Underground, but is it really everyone?"
Your world. No. Your universe was about to be destroyed. As much as you didn't want to leave, you couldn't let him take over. So you did the only thing you could think of. You activated an ancient spell which prevents him from ever coming back to your universe. The bad thing? You can't go back to your universe either.
Suddenly you awake in snow and find yourself trapped Underground, a place inhabited by kind monsters, skeleton brothers, and a young kid who can reset time. As you grapple with your new reality, you realize he is here too, endangering the beings you have grown fond of.
Now, in this unfamiliar world, you must confront the consequences of your actions. Can you protect your newfound companions from the coming shadows or will they fall victim to the evil you inadvertently unleashed?