Disclaimers: I do not own Gravity Falls

Author's Notes: Thanks for reading and please review.

(Back with Bill…)

It was another average Tuesday afternoon at the Pines residence. Having just finished with school Dipper was practicing his Kickboxing in his room while Mabel and Bill watched. Well, Mabel watched, while Bill looked out of his mind with boredom.

Dipper positioned himself in front of a large punching bag which was hanging from the ceiling by a hook. He began with a simple boxer's shuffle as a warm up, before delivering a few jabs.

"How much longer?" Bill complained for what could have been the 100th time.

"Bill I told you I have a tournament this week." Dipper explained again.

"Why do you even waste your time with this?" Bill asked.

"Kickboxing is a respectable form of fighting that combines elements of karate and strikes that can be used for one's protection." Dipper explained as if he was quoting from a textbook. "In fact I've use it to save your butt a thousand times already."

"I mean practicing." Bill clarified for him. "Why are you practicing? Shooting Star isn't."

"That's because I don't let the little things worry me." Mabel said laughing.

"Little?" Bill asked confused.

"I'm going against my arch rival this year." Dipper explained. "He always wins, but this time I'm gonna kick Gideon Gleeful's butt!" Dipper vowed, delivering a roundhouse kick this time.

"Gideon Gleeful? Isn't that the talking bear that used to rummage through my parents' garbage?" Bill asked.

"He's just this creep in town." Mabel explained. "We used to date." She admitted.

"He's only any good because his rich parents buy him fancy equipment and private lessons," Dipper yelled in frustration.

"Say no more kid." Bill said, suddenly perking with interest. "I know a thing or two about rivals, trust me. I can help."

Dipper was about to voice how bad of an idea that was but…too late!

With a wave of his cane the punching bag came to life and wiggled off its hook before standing in front of Dipper at the ready.

"There you fight better when you're actually in danger." Bill reasoned.

Dipper smiled, perhaps this time Bill's magic wouldn't back fire on him. Of course, the moment the thought entered his mind was the moment he was proven wrong.

Dead wrong!

The Punching bag roared and shot out a tongue as long as a giant toad's and lifted Dipper up as if he was nothing.

"Ford!" Dipper had just enough time to scream for help before the beast began to sling him around like a rag doll.

"What in the blazes is…?" Ford stopped in the door way in disbelief, Stan was right behind him.

"Holly Moses Ford do something!" Stan demanded.

"I'm gonna go out on a limb here and say this is your doing." Ford gave Bill a cross look before pulling out and aiming an energy weapon of some kind at the beast.

"Right because it's always me." Bill argued.

"It is always you!" Ford yelled back lowering the gun.

"Aahhhh guys." Dipper pleaded only to scream as his arm hits the wall...HARD

"YEAAOOWWW!"

Ford aims once more and fires.

The punching bag drops Dipper before turning back to normal, but the damage is already done.

"Owe." Dipper yelps as he tries to move his arm.

"Dipper are you okay?" Mabel asked.

"I…I think It's broken." Dipper admitted.

(Sometime later…)

The trip to the Hospital wasn't a fun one and Bill receive a several hours long lecture from Ford the whole way there. A lecture that continued when they arrived, and carried on threw Dipper's arm casting and all the way home. Now Dipper was resting in Bill's bed with a broken arm. Mabel sat beside him trying to convince him it wasn't that bad.

Dipper wasn't buying it.

"Ugh, this is a nightmare! If I can't fight Gideon, he'll say I wussed out, and he'll never let me live it down!" Dipper groaned.

"Might as well give it a rest." Mabel said. "There's no way you're fighting this week. Unless…" She looked to Bill and smiled. "You could just fix his arm!" She said.

"Oh no!" Dipper said, holding his cast arm close to his chest. "You've done enough."

"You know... That sort of spell is not really in my comfort zone," Bill admitted.

"There must be something you can do." Mabel insisted.

Bill didn't blame her, he felt kind of horrible that things got out of hand. He looked thoughtful for a moment and then his eyes lit up. "Well, I could look up a bone-healing spell in the magic instruction book that my father sent me after Sixer gave me the wand!" Bill said, pulling out said book from under his bed and searching through it.

"What, this whole time you had a magic instruction book?" Dipper asked.

"Yeah, the royal family has been using this book for centuries. When they mastered a spell, they wrote it down in here," Bill explained. "But it's a complete disorganized mess, though. It's gonna take me for-eeee-ver to find-" Bill said, before noticing a spell on the page currently opened. "Oh, here it is!"

"Really?" Dipper perked up.

"Hm, it's in an ancient language." Mabel pointed out looking over his shoulder.

Bill raised his cane. "Releasio Demonius Infestica!"

The spell curled around Dipper's cast.

"Ah! Ah! I can feel it working! My fingers are tingling!" Dipper said. He was actually relieved, for a moment there he thought Bill was about to make things worse. Just then the cast gave way to a large blueish teal tentacle type thing replacing his arm, to which Dipper screamed in shock and fear.

"Bill… what did you do?" Mabel said.

"Oh, don't worry, Dipper! There must be a spell in here that can change it back," Bill said, frantically searching the spell book.

"We'll fix it, Dipper!" Mabel said, joining Bill.

Suddenly, Dipper's monster arm knocked the spell book out the window.

"This is a disaster!" Dipper screamed.

"Mason, is everything alright up there?" Ford's voice came from downstairs.

Dipper was about to reveal that everything was in fact not okay, but Bill stopped him.

"Please Pine Tree don't tell him." He begged. "I can't take another lecture, he's worse than my father!"

"Wow that's pretty bad." Mabel noted.

"Dipper?" Stan cut in.

Dipper sighed "Everything's fine." He lied. "I'm just bummed about this weekend."

"Don't sweat it kiddo you'll get him next time." Stan assured him.

"Bill are you staying out of trouble?" Ford cut in.

"Yes." Bill groaned, rolling his eyes. "You see what I mean? Just give me some time I'll fix this."

Dipper doubted it, but nodded his agreement anyway. "Fine."

(The Next Morning…)

Ford and Stan had set off into the woods for a chance at capturing a picture of the allusive Moth man, a creature that locals had reported seeing standing under street lights.

"We will probably be gone the rest of the week." Ford was explaining to Mabel who looked exhausted. "We were going to wait until after Dipper's tournament but now…well."

"It's okay Grunkle Ford." Mabel said pouring herself some Mabel Juice. "We'll stay home with Dipper, besides you two could use a break right Bill?"

"What?" Bill asked, looking even worse than Mabel. "Yeah whatever." He said with a big yawn.

"Alright you kids be safe and go to school." Stan added.

"Like he'd know if we did." Bill half joked.

"Oh, I'll know buddy." Stan swore, his eyes narrowing as he and Ford began to walk out the door. "I know everything that goes on in this place." He then looked to Mabel. "Sweetie you really need to stop partying at night and get some sleep. You look awful."

Mabel forced a smile, "We'll be fine." She assured them before closing the door. "Well at least we won't have to worry about hiding Dipper from them." She said.

"Yeah like that was possible." Dipper said coming down the stairs.

Bill yawned, "Morning, Dipper, morning, monster arm. Mabel and I were up all night, but we haven't found a way to reverse the spell."

Mabel nodded in agreement. "But we'll keep looking." She vowed. "In the mean time we have to go to school."

Dipper's monster arm then grabbed Bill's orange juice and poured it on Dipper's head.

"Super."

(Later…)

Later at school they decided to meet Wendy at the cafeteria for breakfast. They had already eaten at home so mostly it was just to hangout.

"Hey, kid. I got a joke for you!" A guy named Lars was confronting a smaller kid named Francis. "What's the most important meal of the day?"

Lars slapped Francis's tray out of his hand.

"It's breakfast!"

Francis chuckled nervously. "That's a good one, Lars."

He then tried to pick his tray back up, but Lars shoved his face in it.

Dipper's monster arm then punched Lars.

"Hey, who did that?" Lars asked.

Dipper pointed to his monster arm. "Uhhh…" He wasn't sure why it happened, but for some reason his arm had moved on its own.

"Nobody hits Lars-"

The monster arm hit Lars several more times before he ran away crying. Then the arm picked up Francis and cleaned him off.

"I, sir, am in your debt," Francis said.

Several students then crowded the monster arm.

"You're a hero!" Grenada said.

"Can I check out that arm?" Wendy said.

"Uhhh sure." Dipper said extending it out to her.

"So cool." Wendy said petting it.

"I want it to be my boyfriend!" Tambry admitted giving it a high five.

"Hey!" Robby exclaimed.

Dipper grinned at all the attention his monster arm was giving him. Maybe this wasn't such a bad thing after all.

The rest of the day had been just as amazing for Dipper, how you might ask? Well, all his life Dipper was never popular, or cool, or a chick magnet. But today he was all those things and more.

"Dipper want to be my science partner?" a girl asked.

"Sit with us at lunch Dipper please!" BillCiperFan15 begged.

And Dipper was loving it, honestly he never wanted the day to end, but soon it did and the three of them were back at the Shack. Once again they were looking through the spell book when...

"Ah-ha! We found it!" Mabel yelled.

"A reverse tentacle spell… I think," Bill added.

Dipper gives his sister a worried look.

"Maybe try it on something first, Bill," She suggested.

"Way ahead of you," Bill said pulling out a potted plant.

"Returnio Armius Normalritecus!"

Bill's spell made the plant catch fire.

"Yeah I'm gonna go upstairs." Dipper said, before running for dear life. After all, a monster arm was better than no arm at all!

"No, I can do this, I know it!" Bill exclaimed pulling out another potted plant.

"Returnius Armius Normalrinny!"

This attempt only succeeded in making the plant explode. Both Mabel and Bill groaned.

For the next two nights Bill tried to get the spell just right, making it three straight nights spent trying to fix Dipper's monster arm. Every morning they would drag themselves to school and struggle to get through the day, all the while Dipper was getting more and more confident with his new arm.

"Returnio… Armius… Normalrino…" Bill said, very tiredly.

Bill's spell actually worked that time, turning the plant into a normal-looking human hand.

"Bill… you did it!" Mabel said. The hand plant gave a thumbs up in response.

"Dipper!" Bill yelled, racing up the stairs with Mabel hot on his heels with the pot in tow.

In his own room, Dipper was doing one-handed pushups with his monster arm. "673... 674... 675…"

"He did it, he did it, HE DID IT!" Mabel yelled excitedly.

"Hey, I think this monster arm might actually help me take out Gideon!" Dipper said. As he smashed the punching bag straight through the wall with one hit.

"Wait, you're gonna fight with that?" Bill asked confused. Pine Tree didn't seem like his old self. In fact if he didn't know better he would say he was being down right demonic.

"Yeah, that seems a bit unfair," Mabel added.

"Shooting Star is right Pine Tree." Bill insisted. "Now hold still so I can fix you." He said holding up his cane.

"Ohhhh, funny how you never have a problem using your magic when it benefits you, but as soon as it gives me an advantage, you want to take it away!" Dipper said, a bit angry and jealous.

"Dipper, I think that arm's a bad influence on you." Bill admitted.

"And I think, you should go," Dipper said, pushing them out.

"What? Fine! But I don't-" Bill tried to say, but Dipper slammed the door shut.

Dipper sits down on his bed with a huff. "Huh! Man, what do they know?" He asked no one in particular.

The monster arm suddenly comes alive and sprouts a mouth. "Don't listen to them. They're just jealous."

"Wha...?! You can talk?!" Dipper asked. He knew he should be a bit more afraid of the fact that his arm now had a mouth full of jagged teeth and was drooling all over the place, but the arm's voice seemed to hypnotize him.

"You don't need them anymore I can give you everything you ever dreamed of." The arm vowed.

"Really?" Dipper asked. "How?"

"First, we're gonna destroy that little punk Gideon." The Arm told him.

"Yeah..." Dipper agreed.

"Then we're gonna get Wendy to like you."

"Yeah!"

"And then we're gonna slaughter all humans and feast on their bowels!"

"YEAH! Wait, what?" Dipper asked.

"I mean, uh, w-win the tournament!" the Monster Arm said quickly.

"Yeah!" Dipper agreed.

Back downstairs Bill is beyond fed up. "What are we supposed to do now?" He exclaimed.

"Stan and Ford are going to kill us." Mabel admitted.

"That's not what I'm worried about Shooting Star." Bill revealed. "Dipper would never act like that."

Mabel knew he was right. "Look we know where he's going." She insisted. "The tournament is today at the Mall." She revealed. "Maybe we can fix his arm there."

"Okay..." Bill agreed as they took their leave. Once there they made their way through the crowd, eventually sitting next to Grenada and Candy.

"Are you okay, guys?" Candy asked.

"You two look terrible." Grenada added.

Mabel and Bill yawned at the same time.

"We've been up for nights trying to fix his monster arm, then he gets mad." Bill explained.

"Now we've got to come here and watch him and make sure he doesn't kill anybody, you know?" Mabel added.

The Kickboxing Coach appeared and said, "Allow me to introduce our first competitor, Gideon Gleeful!"

Gideon was seen at one end of the room, flanked by two butlers. He pushed them out of the way, then took off his cape, revealing that he had been standing on a footstool.

"That's Gideon?" Bill said, surprised. "That kid can't be any more than eight years old!"

"We love you, son!" Someone yelled in the crowd.

"Why thank you." Gideon said cheerfully to two individuals that Bill assumed was his parents.

"You dated him?" Bill asked.

"He's 13 not 8, plus He's deceivingly charming." Mabel said defensively.

"And his opponent, Dipper Pines," the announced.

Dipper appeared on the other side of the room everyone gasped at the sight of his monster arm.

"Hey, wait! He's got a monster arm! That's not fair!" Gideon complained.

"Yeah, pretty cool, right?" the coach replied not seeing the big deal.

"Okay Bill you should do it now before this gets out of hand." Mabel said, but heard snoring, she turned to see Bill fast asleep. "Oh boy."

Meanwhile the fight began, and Dipper's monster arm coiled around Gideon's neck and tossed him across the room into a trophy shelf, which collapsed and fell with Gideon on it.

"Point, Pines," the coach announced nonchalantly.

"Where are your private lessons now, Gideon? Huh?" Dipper taunted.

Dipper's monster arm picked up Gideon, and started talking, "He's beaten. Now finish him!"

Dipper just stood there confused.

"This is what you've always wanted. Destroy him! Eat his bowels!" The arm growled.

"Not my bowels! I love my bowels!" Gideon said, afraid of what the monster arm would do.

"Listen, I just wanted to win the tournament so he wouldn't make fun of me!" Dipper told the monster arm.

"If you're too weak to finish him, I'll do it myself!" the monster arm said, then tore off Gideon's shirt.

"Bill was right about you! You are a bad influence!" Dipper said.

"And you are pathetic," the monster arm stated, then threw Gideon across the room again, this time into a punching bag, which swung back into Gideon's face.

"Point, Pines," the coach announced again.

Just then the monster arm attacked Dipper.

"Bill?! You can change it back now!" Dipper called out. He looked to Bill hopefully only to see him fast asleep with Mabel and her friends desperately trying to wake him. "Oh boy."

"Bill!" Grenada and Candy yelled.

"You gotta wake up!" Mabel shouted.

Dipper's monster arm kept hitting Dipper against the ceiling, then slapped Dipper with his other arm.

"Stop hitting yourself. Stop hitting yourself." He taunted.

"Hey! Wake up!" Grenada hollered.

"Here try this!" Mabel said, handling Grenada a soda.

"Oh, thank you so much," Grenada said, sipping the soda.

"No! On him!" Candy advised.

"Oh." Grenada exclaimed realizing what she meant.

Bill was suddenly awoken by someone splashing a drink on his face, and what sounded like Candy yelling at him. "Did you just spill coke in my hair?" He asked, his eyes going black.

"Bill!" Dipper yelled.

Bill turned to see Dipper being swung around by the monster arm. "Finally come to your senses hu?" He asked. "Bout time." He added then looked back at Grenada. "We will discuss this later." He vowed.

"It was Mabel's idea." Grenada shouted fearfully.

"Traitor!" Mabel yelled.

Bill ignored them and aimed his cane at the monster arm. "Returnio Armius Normalrino!"

The monster arm dodged Bill's spell, and it hit a punching bag. Which then turned into a hand version of itself.

"Returnio Armius Normalrino!"

The next attempt ended up hitting a dumbbell, which also tuned into a hand.

Bill kept firing the spell repeatedly, but the monster arm kept dodging the blasts turning more objects around them into hands.

"Ugh! He's too wiggly!" Bill complained as the monster arm grabbed onto the rafters above them.

Dipper noticed all the objects on the floor that were now hands and took his chance. He grabbed the arm and pushed up against the ceiling, forcing it to let go. They fell and the hands wrapped around the monster arm, trapping it.

"Now!" Dipper called out.

"Returnio Armius Normalrino!" Bill exclaimed actually hitting the monster arm this time, which began shrinking.

"You'll never get rid of me! I'm part of you! You can treat the symptoms, but you'll never cure the virus!" the monster arm yelled, before disappearing and returning to Dipper's normal arm.

"Dipper, are you okay?" Bill asked as he, Mabel and their friends ran up to him.

"Ugh… Hey, my arm! My beautiful arm! It's back to normal!" he replied.

Just then a snapping sound was heard.

"...And totally broken."

"Still?" Bill asked. "Come on!"

"Broken arm? Hah! Well, it looks like I win!" Gideon said. However, brass knuckles fell out of his sleeves, and one of the arms held it up to the coach.

"Brass knuckles? Seriously?" The coach yelled.

"Brass? Pfft, they're gold." Gideon corrected him.

"You boys have brought shame and dishonor to this great and noble sport. Tis a sad day for strip mall kickboxing everywhere," the coach said, disappointed.

At that, Gideon and his parents walked out.

"Bill, Mabel, I'm sorry. I should've listened to you," Dipper said.

"I know," Bill said.

"We forgive you," Mabel added elbowing Bill in the stomach.

"Hey, uh, when the monster arm said he was a part of me, that's nothing to worry about, right?" Dipper asked.

"Uh, probably not?" Bill said, still a bit nervous.

"Yeah, I wouldn't worry about it," Mabel added sounding a bit more carefree.

Dipper gulped, he wanted to believe them, but something felt…different.

"Let's get out of here." Bill ordered. "I need some more sleep, and a shower." He added glaring at Mabel.

"Not my fault you wouldn't wake up." Mabel said as they began their walk home from yet another glorious adventure.

-To Be Continued