"Where's Frisk?" Sans said over the phone. "You haven't seen her either? I'm really worried." Sans had called Undyne asking if she had seen her anywhere. After what happened at the hotdog stand, Frisk had disappeared in the middle of the night without telling anyone where she had gone. Normally, Frisk and Sans would leave each other notes if they left the house before the other person woke up, but this morning, there was no note on the fridge door or anywhere else in the house. Sans was beginning to panic.
"It's ok," Undyne replied. "Just head to Alphys's lab. I'm sure we can find her on one of the cameras. She probably just went for a walk and forgot to leave a note. She's only human, after all." Sans breathed. Undyne was right, Frisk couldn't have gone too far; she couldn't get out of the Underground anyway. He grabbed his blue hoodie and set out for Hotland.
Yesterday's events terrified Sans. He had never seen Frisk's face look so empty. All the color had left her face. He teleported her home, but she barely said a word to him. He wasn't even sure if she fell asleep. There was no movement from her last night, and he had been holding her all night. No shaking or screaming, but no sign that she had fallen asleep either. She must not have slept at all.
Sans knocked on Alphys's door. He hadn't been back to the secret lab in a long time, not since Gaster had disappeared. He shuddered. All his failed attempts to bring Gaster back were flooding back into his memories. He had avoided coming back to this place for years, but the idea of saving Frisk was more important to him than anything. The only other time he had gone back to Alphys's lab also involved Frisk. She was more important to him than his pride and fears. The door opened and he entered the lab.
"S-Sans?" Alphys said, surprised. "What are you doing here? I-I didn't think you would come back so soon."
"We can't find Frisk." Sans said. "I was wondering if you could find her for me on your cameras."
"Are you sure she didn't just go for a walk?"
"She didn't leave me a note this morning. She always does. I'm worried about her. I just want to make sure she's okay."
"Sans, did something happen?" Sans explained what had happened yesterday after he ran out of the lab. Frisk had become possessed by the other determined being. The entity called itself "Chara" and was attempting to attack the three bunnies that wanted to hurt Frisk. Frisk's entire demeanor had changed, and it was like she was a completely different person. Her face had changed from the soft, warm eyes that Frisk had to red eyes filled with bloodlust. Her cheeks had become bright red and her clothes had changed as well. Sans was only able to stop her by tethering her soul to the ground. When she awoke, Frisk looked as if the determination had been sucked right out of her. She had looked at Sans with dead eyes and refused to speak or make much movement on their way back home.
"I'm afraid whatever is in her head is going to end up possessing her again. I just need to know where she is."
"Jesus, that's so terrifying… Let me get to my computer." Alphys hurried over to her screen. The live feed was not able to pick Frisk up, so she tried to check other places. Frisk was nowhere to be found. "That's odd, I usually am able to find her somewhere. The Underground is only so big." Sans began to panic. What if she was somewhere no one could get to her? What if Chara took over again? Sans wasn't there to help her. "She'd have to be in a place I can't see with my camera. That's really strange." Suddenly, it clicked in Sans's head.
"I know where she is." He turned around towards the exit and sprinted home as fast as he could.
Frisk breathed heavily. The sounds of her breath were the only thing tethering her to this world at that moment. Who was Chara and why did he want to take control of her? She had to stay away from people in case he came back. No one was safe around her.
The moment the bunnies had attacked her, she felt strange inside, like her own determination had been broken and absorbed by another entity. Chara must have been absorbing her determination. How did she become possessed in the first place? She didn't know. All she knew was that he was dangerous and that she could lose control at any time. She had no memory of the event aside from seeing Chara stab open her chest and pull her soul out. When she came to, the soul had returned to her chest once again.
The floors were cold, and she was wearing shorts instead of pants. The feeling of cold on her legs was helping her focus on staying in control. She shuddered; at any given moment, Chara might be back to take her over.
"Why fight me?" Chara began to speak in her mind. "Your determination is strong, but it only helps me grow stronger. I would have grown stronger earlier had you decided to gain EXP, but that's alright. Here I am. The more you stay in the Underground, the stronger our connection becomes. Isn't that right, Frisk?"
"What do you want from me, Chara." Frisk stuttered back. She couldn't speak clearly because of how terrified she was.
"Oh, that's an easy one. I only want your soul and control over your body." She heard Chara laugh in her head. "If I have your soul, I can absorb the other six and we can destroy the barrier. We can destroy the world that's caused me so much pain. It's my revenge." Frisk didn't understand. "Oh, right, you don't know anything about me. Well, that's easy to remedy. Let me show you." Frisk's mind filled with Chara's memories. At first, they all poured into her head at once, and she couldn't differentiate which was which. Suddenly, her mind became blank, and images of Chara's past formed in her brain like a movie.
Chara had fallen down in the same spot that Frisk did. He was scared and terrified but was relieved to be out of that village he considered his personal hell. Life on the surface was miserable for Chara. Flashes of memories of abuse and torment filled Frisk's mind. Chara was hurting. He climbed Mount Ebott in an attempt to escape his hellish life on the surface. Suddenly, a monster approached from the darkness. He was a small child, about Chara's age, and resembled a goat. He asked Chara if he was okay and took him back to his parents.
The next few memories were filled with joy and love. Chara had been adopted by the royal family and treated as one of their own. His adoptive brother, Asriel, watched over and protected him. The two of them were mischievous and did everything together. Asriel's love and comfort towards his brother seemed to ease away the pain of his past for the time being. Chara and Asriel's brotherly bond was the strongest power in all of the Underground.
Chara had overheard his father one day, talking to his mother. Asgore wished to break the barrier and set everyone free so that monsters could live on the surface again. He talked of this dream with hope in his eyes. He thought that there must have been a better life on the surface and that they could patch things up with the humans. Chara, however, knew the truth: that life on the surface was hell, and that humans were the most disgusting race on the planet. Chara loved the monsters so much that he believed keeping them sealed in the Underground was the best option for them. He couldn't let Asgore try and find a way to break the barrier because the humans would destroy them all.
In his mind, Chara began to hatch a plan to eradicate humanity and create a safe haven for the monsters to live above ground. Consumed by his desire to exact revenge on the ones who made his life miserable, he began brainstorming ideas to break the barrier, kill the humans, and release the monsters. He poured over monster history books and spent all day in the library. Asriel had thought Chara was delving deep into his studies to prepare himself for eventually ascending to the throne. He loved his brother dearly and always assumed that the two of them would rule the Underground together when it was time for them to rise to the throne. Asriel had offered to help Chara study, but each time, Chara kept insisting that he had to do this on his own.
Over time, it seemed like Chara grew distant from Asriel and only spent his time in the library. Chara had even began visiting Dr. Gaster in what would become Alphys's laboratory. Chara and Gaster had only worked together for a short time, but Chara allowed Gaster to experiment on his human body. This research, which was carried in secret, was the framework which would eventually lead to Alphys's discovery of determination. Eventually, Chara became well-versed in the knowledge of human and monster souls and bodies.
Concerned for his brother, Asriel tried to sit Chara down to express his worry about their growing distant. Little did Asriel know that the plan Chara had hatched was about to come to fruition. Chara apologized to Asriel for the time they had spent apart and offered to bake a pie with him. Excited to reconnect with his brother again, Asriel accepted. They had grabbed one of the recipes for Toriel's butterscotch pie, but they were out of butterscotch. Chara then offered to try and find some replacement ingredients.
Chara had known of the power a monster soul carries after absorbing a human soul, and creating that scenario was his intention. Chara attempted to substitute butterscotch for buttercups, knowing that buttercups were poisonous to humans. Soon after, Chara became terminally ill. Stricken with grief and guilt, Asriel tried everything to save his brother, but it became apparent that Chara was about to die. Chara's last request was to see the Golden Flowers from his village and he expired shortly after. Asriel, determined to carry out his brother's last request, absorbed Chara's soul just as Chara had predicted. They both had shared control over Asriel's body, and they carried Chara's corpse across the barrier to the surface.
On their way up, Chara finally confessed to Asriel about his life on the surface. He told him of all the awful things he experienced and the abuse and pain he had until he fell Underground. He confessed that he thought humans were disgusting and that monsters deserved to be on the surface. Chara then explained of his plan to wipe the humans out, absorb six human souls, and break the barrier to let the monsters live on the surface.
Upon reaching the village, however, the humans assumed that Asriel had killed Chara, and they started to draw their weapons to kill the monster. Chara had attempted to convince Asriel to use their newfound powers to destroy the humans, but Asriel refused and resisted Chara, not wanting to hurt anyone. The monster/human fusion was destroyed by the humans.
"I can't really remember much after that," Chara reminisced. "But when I came to, I was inside your head already. I was too weak to make a presence, so I just observed as you went through the Underground. I figured that the universe was giving me another chance to free the monsters and kill the humans for good. I'm gonna need your help."
"No," Frisk said. "I refuse to help you. We're not hurting anyone. I won't let you get away with his."
"The more you struggle, the stronger I become, Frisk. Don't worry though, you'll get used to the shared control. It took me a while to adapt too."
Chara's voice disappeared from Frisk's mind and she was filled with a fear she had never known before.