A/N: Chapter 4!

Sans will be spilling his secrets out today and possibly the return of some characters. Also go get yourself a bowl and a spoon and some milk because here come the feel-ios!

ShinyVictini4 - I have even more planned for Asriel for the future! I didn't realize that people didn't like the Sans=Ness theory as much as others until I started writing this, and I'm glad someone does. Thank you so much for reviewing!

DISCLAIMER: I DO NOT OWN UNDERTALE OR ANY CHARACTERS! I DO NOT OWN EARTHBOUND OR ANY OF THE MOTHER SERIES OR CHARACTERS! I only own my OC's and the storyline. I DO NOT OWN THE SANS=NESS THEORY!

NOTE: Frisk and Chara are both non-binary and use they/them/their pronouns. Monster Kid is female, Napstablook and Mettaton are both male. Don't like it then leave (AFTER READING OR REVIEWING!)

Enjoy!

Frisk had helped Asriel walk at first, so he could get used to his legs again. After all, he'd been a flower for how many years now?

They reached their street and Sans blinked. "Toriel must've gotten done with her SOUL school meetings early. She's home."

Asriel's eyes widened.

Sans led them towards Toriel and Asgore's house, and entered before Asriel could protest. "Hey, Toriel?" He called. "There's someone here that you need to see!"

Asriel sucked in a breath and tried to hide behind Frisk.

Toriel hustled out of the kitchen, wiping her paws on her dress. When she spotted her son peeking out from behind Frisk, her paws flew to her mouth in shock. "Asriel?!"

Asriel suddenly ran towards her and hugged her, pressing his face into her dress. She pulled him closer, happy tears leaving tear tracks through her fur. "How-"

Sans shoved his hands into his jacket pocket. "The human souls." After explaining what had happened, he then told Toriel his and Frisk's theory. "If we can activate all the human souls permanently, Asriel's soul should reactivate. Once that happens, his monster form should become his normal one again."

Toriel glanced at the skeleton. "'Reactivate?'"

"A monster cannot live without a soul. Neither can a human, but their bodies persist after death, unlike a monsters'. Asriel still has some sort of soul besides the human souls or else he couldn't exist as Flowey. The reason you lost your ability to feel and have a monster form was because of your soul; it's either fractured or cannot produce your trait," Sans explained. "And if you can't produce your trait, then you can't maintain a monster form. You're VERY lucky that Alphys was able to take the remains of your soul and some of the ash from your monster form and inject it into the flower. Otherwise your soul would have... well, you wouldn't be here."

"Have you told Asgore?" Frisk asked.

The wife and son of King Asgore had their answer plain on their faces.

Sans groaned. "He's one of the only people you should have told right from the start. You know if that if you wait and he finds out by himself, he's not gonna be happy."

"First I want to help Asriel stay as his monster form. Then we'll tell Asgore," Toriel said.

Sans closed his eyes, chuckling. "You're lucky that I know the perfect guy to help you." His left eye opened, glowing blue.

A blue aura surrounded Frisk, Asriel and Toriel. Sans raised his hand and snapped his fingers.

They disappeared, leaving the empty hallway behind.

...

Sans grinned as the other three materialized in front of him. "Arghhhgh!" Frisk moaned. "That feels terrible!" Asriel and Toriel had the same uncomfortable looks on their faces.

"Well, we're gonna have to do it again later," Sans said cheerfully.

Asriel looked around. "Is this... Snowdin?"

Sans chuckled. "Yep." The skeleton began walking through the town, and didn't seem to mind that his slippered feet were ankle-deep in the snow. He led them to his and Papyrus' old house, still lit up brightly. "Now, you can't tell anyone about this, 'kay? You'll be the first to ever know, except for Frisk in other... well, Frisk knows what I mean. Pap doesn't know, and I've had a hard time keeping this from him, so do me a favor and shut your mouths." Sans ducked behind his house and, as Frisk, Asriel and Toriel followed, stopped in front of a hidden door.

His eyesocket lit up and a blue aura surrounded the door, and seconds later it swung open. "Welcome to my lab." Sans was gone, and lights flipped on inside. "You might want to come in, by the way," he called.

Asriel looked around in wonder. "Seems like a very simple lab."

Sans yanked a huge cloth off of a shape at the other side of the room. "That's how I like it." The shape under the cloth was a huge machine, with an open panel.

Frisk stared at it. "What's that?"

Sans chuckled and a massive rolling toolbox shot over from the wall, and his eye lit up as his magic lifted tools into the air. "This is how we're gonna get Asriel to stay as a monster and activate his soul." He grabbed some sort of tool and disappeared under the machine, while the other floating tools began working on various parts of the machine. "I originally tried fixing it to try and get back to... uh, my home, but that didn't work out. So I started modifying it to try and travel to a special place to rescue someone." His voice came from under the machine, and banging accompanied his words. "Every time I get close, everything... well, everything gets reset. And not because of anything I'm doing. It's... something... else." Sans climbed out from under the machine, yanked off his blue jacket and grabbed a different set of tools, diving back under the machine. "But now..."

The machine suddenly roared to life, a screen lighting up in front with seven switches around the screen. Sans yelled, and teleported out, beaming.

"And what does this do?" Toriel asked.

The screen was covered in a strange language, runes that they didn't recognize, but clearly Sans did. His bony hands flew across the screen, rapidly typing and changing things. As he worked he spoke, though he focused on the screen. "We need to get to another timeline. This world is one of thousands, even millions, and we need to get to two of them. Or more accurately, we need to get to one and then an in-between timeline." He stepped back and shrugged his jacket back on. "First I need to tell you something so it's not a shock later.

"I don't know if you knew this but I'm not originally from the Underground. You could say I'm from the surface, but it's a different surface in a different timeline. This machine is what brought me here, but it broke and turned me and Pap into skeletons. I took the remains of the machine and built this thing. It works, but I haven't gone anywhere.

"My name wasn't Sans in my home timeline.

"It was Ness."

...

"I was a human. I had three friends named Paula, Jeff and Poo." He pulled a picture out of one of the drawers, and handed it to them. "We had to go back in time in our machine called the Phase Distorter, and destroy an alien named Gygias. We did, but with a consequence. We created two timelines; our original, and a new one. We returned to our first one and when we got there, the world was warped and changed, and we were forced to run.

"The Phase Distorter was a strange thing though, we couldn't transport organic material in it, so Jeff's father implanted our souls into robots. When we came back to our home timeline I managed to transfer myself to my body again, but my friends couldn't. Their bodies had disappeared. Then the timeline began warping and we had to flee. Monsters such as Starmen and Zombies chased us into the Phase Distorter before we could stop them, and a Starman managed to get in with us.

"And... we used the Phase Distorter."

Sans was crying now, wrapping his arms around himself. He swallowed and continued.

"I didn't know what happened - one minute I was crammed into the Phase Distorter with my friends and a Starman - the next... I was falling, and then nothing.

"I woke up with a skeleton next to me. It wore armor like a Starman's, and then I realized the consequences of putting organic material into the Phase Distorter; you did, but not completely. I becamse a skeleton, and we had come to this timeline, the Undertale Timeline.

"My friends were gone. The remains of the Phase Distorter were scattered around us in the snowy forest. Up ahead I could see a village, so I managed to get there and get the house. It was empty and no one had lived there for years. When I went back to get the Phase Distorter and the Starman, I had no way to get them to the house until my eyesocket began glowing and my magic activated. I don't know if it was my emotions or my soul or the situation or whatever, but it started. I managed to get the Phase Distorter down here and the Starman into the house.

"Snowdin accepted us. The Starman had woken up without any memories and I gave him a name. Papyrus believed, and still does, that he's my brother. I guess we sort of are. Two living things with no way to get back to our home.

"We didn't age very much. Neither did the monsters in Snowdin." Sans finally sighed, rubbing his face to get the tears away. "But I know how to get Asriel help. We need to find someone who can lead us to get help.

"His name was W.D. Gaster. He was a monster who lived here, but after the third reset, he disappeared. No one seemed to remember him... no one else remembered other resets, not even Papyrus.

"And it went on. Until now, when the reset button was shattered and we had this timeline forever."Sans yanked up his hood, the fluffy down casting a shadow over his face. He wiped away the tears and took a deep breath. "We have to get to Gaster in order to find the people who can help you, Asriel."

Asriel looked up at Sans. "Y-you told us your story and your secrets for me?"

Sans rubbed the top of his head affectionately. "Don't worry 'bout it. I needed to tell someone eventually and you guys are my closest friends."

"If this thing is made from the Phase Distorter, won't we...?" Toriel asked worriedly.

Sans waved her off as he pulled an old bag out of one of the drawers. He stuffed the picture, a book and a roll of a blue paper into it, and slung it over his back. A badge with a lighting bolt was attached to it, and it seemed to shine as Sans' hand brushed against it. "No. That part of the Phase Distorter was destroyed. Even if it wasn't, I would probably have destroyed it myself. We're safe."

Frisk reached out and took Sans' hand. We'll be right here, Sans." They smiled at him, and he cheekily grinned back. Or, technically, just grinned because he was a skeleton.

Toriel cried out as a white light enveloped Asriel and when it faded, he was a flower again.

"The DETERMINATION from the green human soul ran out." Sans picked Asriel up in his flowerpot and handed him to Toriel. "Now hold onto my coat and DON'T let go unless you want to get lost between timelines."

Toriel froze as a beeping sound filled the air. Checking her phone, she winced. "Oh no. Asgore's calling me."

Sans hissed. "Alright, change of plans. Forgot he was supposed to be getting back from that conference out of town. Toriel, stay here. Asriel and Frisk, you'll come with me."

Toriel sighed. "Fine."

Sans snorted as she handed Asriel to Frisk. "What, not gonna argue?"

Toriel shook her head. "Nope. You'll just force me to stay." She turned and left the room quickly, pulling her phone out.

Sans pressed a button and the world went dark.

Frisk was floating in the darkness, clutching Sans' coat sleeve and Asriel.

Sans smirked. "Told'ya it'd work." He turned and somehow floated forward, pulling Frisk along.

A shape floated in the distance, a slightly darker black then the darkness around them. Sans grinned. "Heya Gaster."

The shape moved and a white face appeared from beneath the folds of its cloak. "Sans?"

Sans winked. "You betcha."

Gaster looked at Frisk and Asriel. "You brought a human and a flower."

Asriel deflated a small bit.

"Gaster, this is Frisk, and the 'flower' is Prince Asriel Dreemurr. He needs help and you are part of that help," Sans said.

Gaster winced. "My apologies. Asriel, I will help you in exchange for Sans getting me out of this horrid place."

Sans laughed. "We've got that under control. You need to take us to... the Mother Timeline."

Gaster narrowed his eye sockets. "And you're truly okay if it's... that one...?" Sans nodded. "Okay. To the Mother Timeline we go."

Sans snapped his fingers and the machine he had built appeared in the darkness. He and Gaster floated in front of it, Frisk clinging to Sans' sleeve.

Gaster spoke something in a strange language and his eyes flared, his left eye blue and his right orange.

And they disappeared from the dark world.

Ending A/N: So how were those feel-ios?

Sorry!

The next chapter will be out tomorrow. The reason it took me so long today was because I was working on my other Undertale fic and had all this crazy stuff to finish first. Also, I hope you guys liked this! I was going to add more, but it's already kind of a long chapter.

Please leave a review so I can improve my fics for you guys!