(Sans x Reader) When Two Souls Meet

Souls and Spaghetti

"That doesn't mean human souls aren't powerful," he says quietly, giving you a knowing look. "Her determination is what let's her... y'know..."

You look at him blankly, your confusion written all over your face.

"Souls are just theoretical, aren't they?" you ask.

"What, you mean you've never seen a soul before?" Sans asks.

"What do you mean, see a soul?" you ask, completely dumbfounded.

"Heh. Guess I'll have to—" Frisk interrupts him before he can finish his statement. She rushes over to the two of you, and fishes her whiteboard out of your backpack.

"I wanna show her my soul," she writes.

"Alright. Go ahead, kid," Sans says, going back to lounging on the sofa's armrest. "Knock yourself out."

She beams at you and puts her hands on her hips, proudly puffing her chest out. You have no idea what she's trying to accomplish. Then, as if out of nowhere, a ruby red heart appears in the air before her. It's about the size of an apple, and it glows softly in the dim light of the living room.

"What... what is that?" you ask. You're pretty sure that your eyes are the size of saucers.

"That, Buttercup," Sans says, flashing you a grin, "is Frisk."

You scowl at him. Within three days of knowing him, his jokes are already getting old.

"I can see that, Sans."

"No, I'm serious," he says, smile growing at your expression. "That's the kid's soul—the very culmination of her being. That's everything the kid is, was, or will ever be."

"Mmmhmm," Frisk confirms. She runs around the living room a few times, her soul bobbing along with her movements.

"It's made of determination," she says, her whiteboard once again in her hands. "Or, that's what Alphys tells me."

"It's her dominant trait," Sans explains lazily. "That's why her soul's red—it's made outta determination."

Suddenly, a ding resounds through the living room. Frisk's soul immediately disappears, and she goes to fish her phone out of her pocket.

"It's Alphys," she signs.

"What'd she say?" you ask.

She reads the text, and then seems to reread it. When her gaze finally leaves the screen, it has a kind of mischievousness about it. She looks from you to Sans and back again, a smile slowly crossing her face. You've seen that look before—it means trouble.

"What're you up to, Frisk?" you ask as she starts furiously texting with Alphys. She doesn't answer your question, and instead picks up her whiteboard.

"Hey Sans—where's Papyrus?" she asks.

"Dunno," he says. "Undyne's, maybe?"

"'Kay. Thanks."

She tucks the whiteboard under her arm and races out of the house, completely ignoring your inquiry after her intentions.

"Something's up," you note. However, in the face of realizing for the first time that souls exist, it doesn't bother you as much as it typically does.

I wonder... what does my soul look like?

"Seems like it... uh, (Y/N)? What're you doing?" Sans asks, a bemused expression somehow manifesting itself onto his face.