Changes (Gravity Falls Fanfic)

The Unknown Monster

Dipper's POV
When I almost stabbed Mabel I didn't have any control of my body. It was pitch black till I gained control and saw Mabel running with fear and shock in her eyes. I looked down to see the knife I had in my hand and dropped it as soon as possible, I had no idea what I did or if I had hurt her so I decided to not go back till I had figured out what happened. Maybe Grunkle Ford would know but I couldn't risk hurting anyone. I didn't know if it was just me or something did this. I heard foot steps not to far away from me and heard someone yell. "DIPPER, WHERE ARE YOU?!" It was Mabel and she was following me. "Stay away from me, I don't wanna hurt you again!" I yelled back as I kept running and realized that everything went black again. As I was in the darkness. I yelled if anyone was there. I heard a voice I know I heard before. "Well well well, if it isn't pine tree, what brings you to the mind scape." It was Bill Cipher! "YOU'RE DOING THIS AREN'T YOU!" I yelled.
"Sheesh kid relax, I don't know what you are talking about." He said with a devilish look on his triangular face. "It has to be you, riiiiiiiiight?"  Of course I had no idea. "No it's not me but I know what's doing it." He said with a smirk on his face. "What's been doing then, you gotta tell me!" "Well I'd like to but gotta go and remember I'll be watching you!" Bill said as he disappeared. Everything turned white and I see Mabel on the floor terrified with a scratch across her face.

Mabel's POV
As I was catching up with Dipper he suddenly stopped and turned, looked at me with red glowing eyes, and starts to walk close to me. I back up a bit as he laughs evilly. "Bro Bro are you all right?" I asked worried. He didn't say anything back. Then he jumped at me and scratched my face. "Dipper what are you...." As I was cut off by him. "You poor thing, wanting you're twin back, well I got news for you... He's mine now, GOT IT!?!" I started to cry a bit but I noticed something, he did too!
"Dipper?" I said half crying. "No.............. Stop I hurt you didn't I, just don't look for me and leave me alone. I don't want you injured or worse!" He yelled to me. I decided that maybe Grunkle Ford could help. So I went to the Mystery Shack and found him. "Mabel, what is it, wait you're face, what happened?" Grunkle Ford asked me. "Well, it's Dipper he seems to lose control and attack me. Then after he does he gains back control then  runs away." I replied. "Well it could what causes this is the Serflet (pronounced surf-let). It's bite is full of poison and can cause one to go insane!" Grunkle Ford said with a worried tone in his voice. "What's going on guys you seem worried?" Ask Grunkle Stan. "Uh how do we explain this easily hmmm....... Well (read this part really fast lol) we found out Dipper been bit by a poisonous snakelike thing and attacks randomly when he loses his control over his body and ran into the woods." Mabel said fast. "WHAT!" Yelled Grunkle Stan. "We gotta do something about this NOW!" So we got a lantern and went out into the darkness. "Heh if I find Dipper first maybe I can use him for Mabel to be my girlfriend." Said Gideon Gleeful. "Hmmmm I gotta make a plan OH wait, I don't need one!" He said with hand cuffs attached to a chain.