You, the human, has been residing with the skeleton brothers for a good while. It was quite the experience, getting to explore the Underground, learning about the history and culture of Monsterkind... Honestly? With all the bullshit happening on the surface, this was a very nice change.
Well, Sans, the one who's usually relaxed and a-okay, wasn't feeling so chill today. He decided to talk to you about whatever was bothering him. He wasn't sure if you'd feel empathy for him, but it's better than worrying Paps and burdening him with this... He explained his entire backstory to you. During that wretched horrible war where humans attacked monsters suddenly and viciously, he lost his Mom. In reality, this was a very long time ago, in 1200. But he never forgot. He never forgot how he witnessed her die infront of him. After the monsters were trapped in the Underground, he was forced to raise Papyrus himself from then on. He vented to you about how he just wished his Mom was still here, and how he hated how much he had to suffer to get to where he is now. He missed his Mom. You, having never seen Sans so distressed before, wanted to help him out. The story was really sad, and you felt bad for him, the poor guy.
After months of blueprints and theories, you two managed to build a whole machine which can revive monsters by memory and monster magic. Blueprints spread across tables in the basement lab, like a second language only the two of you understood. You and Sans stayed up late at night, theories being jotted down on notebooks, arguments debated about soul resonance stability, monster magic retention, and whether memory could be used as a structural anchor without corrupting identity. Sans didn’t fully believe it at first, and he thought it was just something you were going to waste the DETERMINATION in your soul over. Despite that, he still showed up every night after dinner to let you help him out. Eventually, it worked.
It was almost 9 PM, and the two of you were in the basement lab. You hooked Sans up to the machine, and the chamber activated. Light filled the room in controlled pulses, as if a heartbeat in the machine was trying to stabilize itself into something real. You were encouraging Sans to keep on going and using his magic to help her become real, and he actually kept on going despite the strain. The machine hummed… then stopped suddenly. Your heart sank, thinking it was yet again another failure, when from within the chamber, the two of you heard... "Uh... Hello?"
You quickly helped the chamber door open, and she stepped out. Arial, Sans's mother, stepped out. Sans was in shock. She was the same, same armor, same everything, on the day he witnessed her death. "Sans? Wha-What's happenning?" She walked towards him, sizing her son up in disbelief. "When did you get so tall, sweetheart? Sans was speechless. She then noticed you, a HUMAN, standing right beside him, and her entire demeanor changed from shocked to on-guard. Recognition filtered through survival instinct, and it seems like this soldier was reacting before thought can catch up. Her gaze locked onto you. The red scarf at her neck shifted slightly as she turned, analyzing everything at once—the room, the machine, Sans, and then finally you, as if placing you into a category she hasn’t decided yet.
“A human.” Behind her, Sans stiffened, almost forgetting she died fighting against your race. "Sans, get back, it'll attack us anytime soon!" Her left eye flared orange in a mix of emotions; motherly care, a soldier's instinct, and fear that she'll be killed by what she thinks is a vicious thing. She doesn't even know where she is, she doesn't even question her son suddenly in his adulthood, she just shields him and holds her close to her. "Stay away from my boy!"