Summary: Taking a different path through The Hall of Egress sends Finn somewhere new.
The last thing he could remember was tripping into a seemingly endless dark pit. The cavern he'd entered after the trap sealed him in disappeared from view as he fell. Finn screamed into the darkness, fully expecting the bottom to lead to his death. Everything went black as he was surrounded by a strangely sweet smell...
Someone prodded at Finn's cheek, strangely insistent. He groaned and batted them away. "Five more minutes, Jake." Small hands grabbed his shoulder and shook. He reluctantly openopened his eyes to see that he was not at the Treehouse and the person waking him was not Jake.
"What The Stuff?" He scrambled away from the unfamiliar person.
The person watched him curiously, not saying a word. They picked up a stick and poked his leg.
"Quit it." Finn sat up and watched them closely. They looked different from most of the people he saw around Ooo. They seemed... more like him. More complete. "You're... a human."
The other human paused before nodding. They pointed at his hat with their stick, baring their teeth.
"I'm a human too, this is just a hat. See?" He pulled off the hat to demonstrate. That seemed to be the wrong thing to do, as they immediately raised their stick to defend themselves. "Woah calm down, dude! I'm a good guy... Do humans not wear animal hats down here? Are there other humans down here? I've only met a few humans before, what are they like? Oh, judging by your reaction they probably aren't very nice, huh?"
The human blinked, surprised by just how much he was talking. They relaxed and started to write something in the ground using the end of their stick. Finn moved towards them and read the word they'd scratched into the ground. "Frisk? Is that your name?" They nodded. "Nice to meet you, Frisk, I'm Finn. Do you know how to get out of here? Jake must be worried sick."
Frisk nodded and took his hand, leading him down a thin hallway. As the pair stepped through a doorway, Frisk stopped, as if waiting for someone. Finn jumped in surprise as a small yellow flower popped out of the ground, a bright grin on its face.
"Howdy! I'm Flowey. Flowey the Flower! Gee, its been a long time since any humans have come through here. You must be confused. Don't worry, Your old pal Flowey will show you how things work down here. Ready? Here we go!"
Before Finn had a chance to even react, a sharp tug on his chest caused an ethereal blue heart to fly out of his chest. A smaller red heart floated out of Frisk's chest, but they seemed unfazed. They almost looked tired.
"See that heart? It's your soul. The very culmination of your being." A feint box appeared around his and Frisk's souls. "Your soul starts out weak, but you can get stronger as you gain LV. What's LV?" Finn noticed his own LV was at 5 while Frisk's was much lower at just 1. "It's LOVE of course!"
Finn frowned, this wasn't right. His instincts told him something was wrong about what Flowey was saying. Finn realized he could still controll his soul and moved it in front of Frisk's as Flowey unleashed a barrage of white pellets. He yelped in pain as they made contact, proving his theory right. Flowey grinned, viciously. "You. Idiot. You thought you could protect your little friend? That's not how this world works. In this world, It's kill or be killed."
More pellets slammed into his soul, slowly whittling away his HP. Just as Frisk's HP was about to drop to zero Finn managed to pull out his sword and attack the murder happy plant. "What? But.. Its not your turn?"
A fireball appeared and knocked the flower away. Finn sighed with relief as a tall goat woman strolled up to them. "What a horrible creature, torturing a pair of poor innocent youths. Do not be afrafraid my children. I am Toriel, caretaker of the ruins. I pass through here every day to see if anyone has fallen down here. You're the first humans to come here in a very long time. Come. i will guide you. This way, children."
"Thanks a bunch, Mrs. Toriel. I thought we were goners there for a sec." Finn picked up Frisk, not wanting to let them trail behind too far. He was surprised at how calm they seemed after that whole situation.
Toriel smiled as she led them into a room that was far brighter than the last one. "It was no issue my child."
"You don't have to call me that, My name's Finn and this is Frisk." The younger human waved. "And I'm not a kid, I'm 16."
"It might have been a long time since I've seen a human, but I recall that most humans are not considered adults for a good few years more." She giggled.
Finn blushed in embarrassment. Frisk gave him a sympathetic pat on the cheek.
"Ah, you must be wary, there are many dangerous puzzles here in the ruins. Here, allow me to demonstrate." She walked along a group of large buttons, activating them in a specific order. Flipping a switch caused another door to open, to Finn's surprise. The next room also held a fairly simple puzzle that Frisk solved in moments.
"Living as a human in the underground, many monsters may try to attack you. when they do you will enter a FIGHT. I would like you to try to instead resolve the conflict peacefully. Try practicing on this training dummy."
"Why? If they're attacking us then we should fight back." Finn said
Toriel seemed surprised. "That may be how things are on the surface, but here all monsters coexist. There's no need to fight just because of a misunderstanding."
Finn thought about it. It didn't hurt to try a peaceful approach. He knew he could probably take any one who did try to actually kill him. "I guess I could try." He walked up to the dummy and saw his Soul pop out of his chest. It was significantly less shocking this time.
This time, once the box appeared, a series of options also appeared. Fight was Finn's first option, followed by Act. He selected Act, to Toriel's approval. This is hardly the weirdest thing that's ever happened to me. The Dummy immediately released his soul.
Toriel led them through several more puzzles that became more and more tedious, all of them fairly simple. Well, simple for Toriel. They barely managed to do anything before the Goat woman intervened and completed them for them. The final 'puzzle', was just walking down a- surprisingly long- hallway. Frisk actually seemed a bit amused when Toriel popped out from behind a large column.
"I have a few errands to run, please stay put until I return. Oh! Here is a cell phone, please call if you need anything." She handed Finn a phone, which he planned to hand to Frisk once Toriel left. "I'll be back soon."
AN: UWU I think this is my first crossover? Please R&R, I Guess. Also drop by my tumblr if you want.