"Sans! We're back!" Frisk shouted, as she and Papyrus came through the front door. She waited for a reply, only to not get one. "Is he still asleep...?" She muttered under her breath. "Papyrus, I'm just going to check on Sans, okay."

"DON'T WAKE HIM, HUMAN."

"I won't, I won't." Frisk reassured him.

Arriving at Sans bedroom door, she carefully opened it and peered inside. However, it was too dark for her to really see clearly from where she was standing. Quietly tip toeing inside, she edged her way towards San's bed and her eyes widened.

"PAPYRUUUUUUUS!!!!" Frisk screamed at the top of her lungs. Confused and startled, Papyrus suddenly burst through the door with a feather duster in his hand as a weapon.

"WHAT IS IT HUMAN?! DO NOT BE AFRAID! I, THE GREAT PAPYRUS, SHALL PROTECT YOU!"

"I-It's nothing! It's just, Sans is gone!" Frisk cried, pointing at his empty bed covers.

"WHY SO CONCERNED HUMAN? HE MIGHT JUST HAVE GONE TO GRILLBY'S OR SOMETHING." Papyrus shrugged. Frisk bit her lip in thought.

"But he doesn't seem well! He should rest! ...Wait, why did he have to rest. What happened while I was gone?" Frisk wondered.

"WELL, ER..." Papyrus thought for a moment. "HE SEEMED STRANGELY FREAKED OUT WHEN I FOUND HIM IN MY ROOM EARLIER TODAY. HE WAS CRYING FOR SOME REASON, WHILE HOLDING MY SCARF IN HIS ARMS." He pointed at the red scarf around his neck. "HE LOOKED LIKE HE'D SEEN A GHOST!"

Of 'course! Frisk thought to herself. Me and Sans are the only two people who actually remember the past timelines! Papyrus and everyone else have no clue! He was talking about Chara, and about the fact that she might return. If Sans saw Papyrus' scarf on the floor and started panicking and crying, he probably thought... He probably thought maybe Chara had done something to him...

"Papyrus! I need you to stay here in case Sans comes back! I'm gonna go look for him!"

"BUT--"

"No buts! Stay here! I'm gonna go see if he's at Grillby's. If he isn't... I might have a good idea as to where I MAY find him." Frisk said. "If he gets that far..." She mumbled. Running out of Sans' bedroom and past Papyrus, she grabbed her coat and boosted out of the door. She was really hoping she wasn't going to have to go THERE again... The place that she had visited, time and time again... But if she wanted to find Sans... If that's where he was headed... Then she had no choice...

****

When she reached Grillby's and asked him if he had seen Sans, all he could do was shake his head. She frowned, thinking of where to look next. She searched almost everywhere, until she had two final places to look.

Seeming out of breath, she knocked on Alphys' door. Shortly after, Alphys came to answer looking quite startled.

"O-Oh Frisk! Thank god y-you're here!" Alphys stuttered, pulling her inside.

"Alphys! What's going on?! Is Sans here?!"

"Y-Yes! H-He's here! He g-got here about half an h-hour ago. And then he p-passed out and hasn't r-regained consciousness. I d-don't know what's g-going on with him. H-He seemed really panicked a-about something. H-His soul seems pretty erratic."

"Where is he?! I want to see him." Frisk frantically asked. Alphys pointed towards a big white metal door. Leading Frisk along, she opened the doors and they both found themselves in a brightly lit white room. The room was lined with beds, which in one of them, lay Sans. Feeling extremely worried, Frisk ran over to him and looked down at him. Even unconscious, he looked scared.

"Do you have any idea what's happening to him?" Frisk wondered, staring at Sans and placing a hand on his forehead. She bit her lip in worry, as Sans' breathing was pretty irregular. Alphys frowned. She pushed her glasses up, almost as if she'd been watching too much anime, as there was a slight glint that shined on them as she spoke.

"I-It's hard to s-say." She admitted. "L-Like I said, his soul s-seems irregular. I-It's not normal. I-It's almost as if..." She hesitated.

"Almost as if... Almost as if what Alphys?!" Frisk cried. Alphys pushed her index fingers towards each other in thought.

"I-it almost seems as i-if two souls a-are fighting within the i-inside of his b-body. His own monster soul, as w-well as one other. The o-other seems like a h-human soul. But not one of a h-human who is c-currently alive. But I'm n-not sure how this c-could have happened." Alphys frowned.

"A human soul...?" Frisk repeated. "Could it be...?" She mumbled to herself. She slowly raised a shaking hand to her necklace again. Looking at it in wonder, she took it off and passed it to Alphys. "Can you examine this?"

"W-What? Isn't this t-the necklace you were w-wearing at the Christmas p-party?" Alphys wondered. Frisk nodded.

"Yeah. I thought that I might have been given it before I had fallen into the underground and met all you guys. But that's not it at all. It belonged to another human who I think probably came before me, but she must have died. Died an angry and vengeful soul. I feel like she may have put her soul within the necklace, but it's probably empty now. I want you to see if you can find that out for me."

"W-Well... I guess I could t-try if there was any sort o-of soul remaining in it before i-if it is empty... I'll give it my best s-shot." Alphys smiled. Frisk grinned back.

"Thank you so much, Alphys. I'll stay here with Sans while you run some tests."

"A-Are you sure?" Alphys wondered. Frisk nodded in confirmation, putting her hand on top of Sans'.

"Positive. I think Sans really needs someone right now..." Frisk frowned, looking at his unconscious, but terrified expression. Slowly, Alphys nodded.

"O-Okay. W-Well, I'll be in the room a-across from this one. If you need a-anything let me know. O-Or if you're hungry, U-Undyne might be willing to c-cook you something. After all, s-she's probably a b-better cook than me.. Haha.."

Frisk giggled. "Okay, thanks Alphys."

Alphys replied with a small nod, and quickly scurried out of the room. "I knew I shouldn't have kept that necklace..." Frisk mumbled to herself.

All the times when I felt super uneasy wearing it... That time when I decided to wear it on that Christmas party, and I thought for a second that I had seen Chara's reflection in it rather than my own... She was probably waiting for this to happen... I just don't understand why she chose to possess Sans instead of me. Perhaps it was because for some strange reason, Sans seemed more vulnerable than me... I'm sorry Sans... Frisk felt a tear go down her cheek, as she tightened her grip on Sans boney hand.

"h-hey... not so tight..." She heard Sans' voice chuckle. Her eyes widened, as she saw Sans slowly waking up.

"S-Sans! A-Are you okay?!" Frisk asked. Sans shrugged.

"i... i don't know to be honest... i feel strange."

"Yeah... I thought you might... Sans, I'm gonna need you to remain calm."

"huh?"

"I think... I think there's a chance that Chara's soul is trying to gain possession over your body and your soul. I've come to believe that her soul was waiting in this necklace I had found. And for some reason she chose to try and mess with you. For some reason you seem more vulnerable than me. And I'm not quite sure why... You probably have your reasons... But Sans, I think the only one who is going to be able to fix this is you. You're going to have to fight against her soul and her messing with your mind... I know it's easier said than done – actually being someone who was once possessed by her madness... But I need you to do that for me...." Frisk said. She gritted her teeth in fear. Tears continued to spill down her face. "I don't want anything to happen to you! You're my best friend, Sans!" Frisk cried. Sans' eyes widened.

"shh don't worry kiddo..." Sans murmured, pulling Frisk into a hug. She rested her cheek on his shoulder, as she continued to cry. "i don't want anything to happen to all you guys either... i'll try my hardest not to let her win... you guys are all i have..." Sans muttered.

The two of them sat like that, for what seemed like forever, as Sans lightly brushed the back of her hair with his hand to calm her down. To interrupt the two of them, Alphys came along and cleared her throat, as she stood in the doorway to the next room.

"I-I have some results... If you guys could p-please follow me."

****

After helping Sans out of bed, Frisk led him along as the two of them followed Alphys to the next room. Many shelves and cabinets were lined with nothing but pieces of paper with scientific scribbles on them. Some of the pieces of paper even looked like they had symbols on them, which Frisk couldn't seem to make out, no matter how she looked at them.
Alphys walked up to the big computer in the center of the room and started typing things into the keyboard. She pointed at the screen.

"S-So... I ran some tests on that n-necklace you gave me. And it does s-seem like a soul resided within i-it, before it was empty. I could explain to you h-how I found this out but... I think you'll j-just get bored with my scientific e-explanation." Alphys chuckled.

"A human soul... So that settles it. Chara was the one who was inside that necklace.... And now she's inside Sans' body..." She frowned. Sans stepped forward to speak.

"hey alphys, you don't think it's possible to remove the soul from my body, do you?"

Alphys frowned. "W-Well, that's hard to say S-Sans. I've had many scientific s-studies and all sorts to do with s-souls... Mainly monster souls... But I don't think I-I've ever tried to extract a s-soul from another person's body."

"i see..." Sans frowned.

"So after all the time of studying souls, you still haven't worked out that...? That's a bummer." Frisk muttered, crossing her arms. Alphys slowly nodded.

"W-Well, it's not like I always h-had help when it came to s-scientific studies. I mean, I-I usually prefer to just watch a-anime. But a scientist by the n-name of W.D Gaster thought I was p-pretty smart so... H-He wanted my assistance for some of t-the science s-stuff."

"W.D Gaster...?" Frisk repeated. She frowned. "Is he still around? Maybe if we find him, we can--"

"NO!" Sans snapped. Frisk and Alphys' eyes widened. Frisk stood, startled at his sudden reaction.

"Sans...?"

"no.... we are not gonna ask G to help us... we can figure this out on our own."

"G...? You talk about Gaster as if you know him or something. Like, personally. Were you two friends or something?" Frisk asked. However, Sans didn't answer. He looked pretty frustrated, and it seemed like he didn't like Frisk asking questions. Instead, she kept her mouth shut and decided not to ask anymore.

"W-Well, as far as I know... He's not a-around anymore. He disappeared quite a l-long time ago. If anything I'd expect him t-to still be in the underground. B-But I don't know."

"I see..." Frisk mumbled. "Well thanks for the help Alphys... We'll let you know if we need you for anything else."