Trapped: Storyboard (chapter 6)

Some months later happened a curious occasion. 

One evening skelebros were visiting Dreemurs family, tho goat family itself was out and  at home was only human. It wasn't so surprising, Toriel and Asgore lately had a lot of stuff to deal with. Curious was Frisk who acted... weird. It would be difficult to say so if both brothers didn't know him too well.
While Papyrus was talking with human, Sans sneaked in Frisk's room... looking for Chara. On his bed was laying a tablet, playing some random videos, but no one in. Sans took a heart necklace from the table, on what Flowey commented:

- Don’t even try to steal it, I’m watching you, bag of bones.

Sans put it on himself. Indeed, on the bed was laying Chara watching video on tablet and pretending that everything is fine.

- Took you awhile, - mumbled the child still staring on the tablet.

  From their conversation they concluded that Frisk in living room isn't their Frisk. He acted weird, obviously didn't know about Chara's existence and she sworn she saw his soul glowing with green.  As much as Sans didn't really like this child, he knew Chara considers Frisk as older brother and worries about him, even if is even more tsundere than Tsundereplane.

They agreed that they need to get their Frisk back, ofc they do. And if it's not him inside that body... who? And how this happened? Although they couldn't answer the first question, the second was obvious - behind this stands anti-monster organization and Frisk's mother.
Sans proposed to ask Gaster for help or get answers from fake Frisk, but Chara said she know where one of their labs it. It's not the principal, but the closest one. And maybe they can find Frisk or at least something there.

During their adventure to the lab and in the lab, they tried to play in stealth mode as much as it was only possible, which was easy for Chara - she's just a ghost, Sans learned from girl that she's just like Frisk. She came from same organization, same labs and experiments. Just it happened much earlier and any things went worse for her... maybe because of that she hated humanity and not only these people. And it was a reason she wanted Frisk to help her, to make him hate them as much, not only them but all humans! And... she was the worst human, why not start with her. It never worked. In the end, she just allowed Frisk to prove her being wrong and promised to help him to take this organization down.
It didn't make Sans hate her less, but at least he could understand her... and think that maybe he has the same set of mind.

They found Frisk's soul in one of the lab. There was not only his soul no, there was few of them. Chara could hear Frisk, who explained that woke up here and last he remember he went in the morning to run with some friends. These souls are from experiments who died or were "failed" and not longer needed. Just like the one in his body now. They just wanted to use that soul to ruin everything from inside...

They brought back the soul, and found fake Frisk in the living room tied up on the chair. There already was Gaster, who helped with transferring soul back and getting information from green one but it didn't say anything new  mostly because it wasn't anything but a loyal puppet.

And this event had consequences they couldn't even imagine.