Dipper woke with a yawn - which abruptly morphed into a scream as he found himself falling through the floor.
"Why am I incorporeal?!" he squeaked, staring wide-eyed at his translucent hands. "What's happening? Mabel? Grunkle Stan? Anyone?!"
No response.
His heart might have been racing were he not suddenly a ghost for whatever strange reason. Brows furrowed in confusion, he flew right back up through the ceiling and into the attic again, only to find his body sitting up in bed. His own back was turned to him, but he knew.
"Bill!" he realized with a horrified cry.
"Heya Pine Tree!" The demon twisted his neck a complete 180 degrees, yellow eyes piercing the incorporeal child. "This bed doesn't have enough rusty nails for my liking. I'm gonna change that!"
"What are you doing in my body? And how?" Dipper demanded.
"Isn't it obvious? I want to make your life a living nightmare! I am a dream demon, after all."
From the other side of the attic came a sleepy moan. "Dipper?" Mabel rose from bed and rubbed at her eyes. "Were you talking about Wendy in your sleep again?"
His ghostly form flushed with both embarrassment and frustration. "Mabel!" Obviously, she didn't reply. So he flew in front of her face, wildly waving his noodle limbs and screaming nonsense all in an attempt to get her attention.
She didn't notice him. He gave up with a huff of irritation. "Dunno what I was expecting," he grumbled as he folded his arms across his chest.
"Wendy?" Bill questioned. "You mean that hot redhead?"
Mabel rolled her eyes. "Everyone already knows how you feel about her Dip-Dop, it's super obvious." She blew a raspberry in the direction of his possessed body. "No need to be all weird about it! Pfff, who am I kidding, you're always weird!"
"Yeah I am, what's your point?" Bill declared much too happily, his grin widening to a disturbing degree, gums flashing in the early morning light streaming through the window.
She blinked in confusion. She had clearly noticed something wrong. Dipper smiled with hope swelling up inside him - maybe she could stop Bill and get him out of his body!
His hopes were crushed when she skeptically narrowed her eyes and asked, "Bro-bro, did you get into the Smile Dip?"
He groaned in frustration. "No, Mabel no, it's Bill, it's… ugh!"
"Smile Dip…" Bill blinked his eyes, slowly, one at a time. "Whaddya know, Shooting Star, that actually sounds pretty good! Maybe you're not the stupid flesh-bag I thought you were!"
Her lips parted in surprise as realization dawned on her face. "Wait -"
Dipper's possessed body slipped off the bed, Bill cackling as he swayed on unsteady, scrawny legs. "Time to go skewer this pathetic meat sack with a dozen rusty forks!"
Mabel leaped to her feet, jabbing an accusing finger in her twin's direction. "Bipper!" she yelled.
"Finally she gets it," the ghostly Dipper grumbled in annoyance as he rolled his eyes.
"Yeah, this is going to be fun. You want to join me, Shooting Star? I think you'll find pain to be absolutely hilarious!"
"Get out of my brother's body, you creep!" And without warning she lunged for him.
Bill laughed in amusement and clumsily sidestepped her attack, coming to faceplant on the ground beside her. Immediately he got to his feet again and stumbled out the door. "See ya later, kid!" He reached to tip his top hat, but realized with a frown of disappointment that he wasn't wearing one. "Yeesh. Pine Tree has no fashion sense," he grumbled.
"Get back here!" Mabel growled.
He pretended as if she hadn't said anything. "Watch me go down the stairs backwards!" Bill's uncanny grin grew wider, and without looking where he was going, he took a step backwards, foot missing the stair by a mile and causing him to tumble head over heels down the stairwell.
Dipper cringed as he watched his body suffer such horrible abuse. "That's… that's gonna hurt."
"Dipper!" the elder twin shrieked. She rushed to the top of the staircase, worriedly looking at the crumpled body of the boy a few yards below.
"Hah! Never said I was going to walk, did I?" He stumbled to his feet with a cackle and brushed himself off. Then he headed straight for the door.
"Grunkle Stan!" Mabel called desperately.
"What is it, pumpkin?" his gruff voice yelled from a different room.
"Dipper's possessed by a demon again! And he's trying to escape! Stop him!"
"I'll get the holy water!"
Bill rolled his slitted black pupils. "Stupid three-dimensional mortals, trying to ruin my fun." He slipped out the door before anyone could catch him. "Hey Pine Tree! Ya there?"
Dipper phased through the wall. "Give my body back!"
"Not until pigs fly! And that doesn't happen in this dimension!" Then he paused. "Wait -"
Suddenly a chubby pink blob came hurtling through the air at him. Before Bill even had a chance to widen his already unnaturally wide mouth, Waddles collided with his face, sending the two rolling across the grass in a ball of flailing limbs.
"Get him, Waddles! Attack pig go!" Mabel cheered as she excitedly punched the air.
Dipper couldn't help snorting in amusement.
"But you aren't supposed to fly in this dimension!" Bill protested as he wrestled the fat little ball of pork. "Get your ugly feet out of my face!"
Poor Waddles hadn't really been too invested in the fight to begin with. He'd only attacked because his master had thrown him at the boy. He quickly found himself tired of the battle, and with an oink he merely crawled off Dipper's fallen body and plopped down into the grass a few feet away, staring at him blankly.
"Lot of good that did…" Dipper looked at the spectacle, unamused.
Bill got to his feet with a huff of indignation. "Whatever. I'm gonna go ruin Pine Tree's life now, and you can't stop me!" He shot a glare at Mabel and her beady-eyed pig companion. Then he bumbled away.
"...Grunkle Stan, did you get the holy water yet?" Mabel shouted into the house.
"Just a sec! Gettin' my gun!"
"What?!" Dipper spluttered in horror.
Mabel gasped. "We don't need a gun! This is my brother!" She frantically flailed her arms as if that would stop her great uncle from attempting to hurt her poor twin.
Mr. Mystery stepped out of the shack clad in boxers and a grimy tank top, bottle of holy water in one hand and sawed off shotgun in the other. "What? No, I'm not using this thing on your brother. It's for that jerk." He nodded towards a man standing atop a ladder, hammering a sign onto a tree along the edge of the parking lot. Stan's eyes narrowed. "No room for trashbags like him at my shack. Oh, he thinks he's so high and mighty on that ladder, does he? Well I'll shoot him off his high horse!"
Mabel hesitated for a moment - then she grinned. "Yeah! Get him, Grunkle Stan!"
Dipper facepalmed.
Bill cackled as he tripped and flailed his way through the streets of Gravity Falls. It was plenty fun to inhabit Pine Tree's pathetic body and wreak havoc on it, but no - that alone wasn't enough. He needed something much worse. Something life-destroying.
His golden gaze landed upon the tap-dancing form of Toby Determined.
A slow smirk crawled across the possessed Dipper's lips. Yes. Perfect.
Bill burst through the door into the building, which seemed to be composed mostly of floor-to-ceiling windows, with a long mirror covering the entirety of one wall. Toby watched his disgusting reflection flailing its limbs in a pitiful imitation of dancing. "Ha-cha-cha!" he cried into the empty room with a wide smile on his fat mouth, revealing rows of ugly yellowed teeth.
Bill folded his arms across his chest and leaned against a nearby wall. "Heya, hot stuff."
"Waaa!" Toby jumped in surprise at the new voice. Apparently, despite the gigantic mirror he'd been staring into this entire time, he somehow still managed to miss the child's entry.
"Got any plans tonight?" Bill waggled his brows.
"Actually, yes!" Toby replied with an awkward kick of his leg in what the demon could only assume was an attempt to continue dancing. "I've got dinner plans with my wife!"
Wife? Bill thought incredulously. How could Toby of all people get married? But he simply sighed and shrugged his shoulders. "Shoulda guessed. It was too much to hope for that someone as sexy as yourself was free."
Toby stuck out a hand and waved his fingers, revealing a makeshift ring on one of them that looked like it had been made out of cardboard and tape. "I'm married to Shandra Jimenez!" he declared proudly.
Yeah, sure, her cardboard cutout, Bill thought with an inward roll of his eyes. "That's just too bad. I honestly don't think I'll ever find anyone as amazing as you. A talented dancer with unmatched good looks?" He shook his head.
Toby faltered. "Me? A talented dancer? Well I don't know. Maybe I could go with you to just one dinner. But my wife…"
"I don't want to get between you and your wife," he replied with false disappointment in his tone.
"You're Dipper, right?"
Bill smirked. "Dipper Pines," he said with a nod. "But you can call me the guy of your dreams."
Toby actually blushed.
With his work finished, Bill winked, turned on his heel, and made an actual conscious effort not to trip on his way out the door. Dipper's pathetic spaghetti limbs made that task incredibly difficult.
As he walked, his gaze drifted to the window of a store that looked to be abandoned. In the window was a stand displaying dusty packets of a certain powdery pink candy.
An eerie, wide grin split the possessed boy's mouth. What a wonderful way to finish this day off!
Dipper awoke with a dusty substance on his face. He wiped it off with the back of his hand, noticing that it was pink.
Oh no…
His gaze traveled over his surroundings. He appeared to be lying on the hard wooden floor of the Mystery Shack's gift shop, a familiar pink packet open and empty on the ground next to him. The wide-eyed smiling dogs on its front stared at him with dead expressions.
"Smile Dip," he breathed in disbelief, groaning and burying his face in his hands. How and why had he gotten his hands on Smile Dip?!
"Bro-bro!" Mabel bounded into the room, concern on her face. "Are you okay?!"
Before the confused boy could do anything, his twin grabbed him, pulling his face close to hers and staring into his eyes. She let out a sigh of relief.
"Okay, you're good."
"Mabel, what was -"
Suddenly a loud knock echoed through the mostly-empty gift shop. Dipper jumped in fright. The twins directed their attention to the door.
"Kids! Get the door!" Stan yelled from another room. "I'm at a good part in Baby Fights!"
Mabel's amber gaze slid to her brother. She stuck out her tongue. "Not it!"
"Aw, man," he groaned. "Come on, Mabel…"
Reluctantly, Dipper walked to the door, pulling it open to be greeted by an unexpected guest. His brows furrowed in surprise and confusion. "Um… Toby?"
"I thought about you all night!" Toby blurted, wringing his hands in his ugly white shirt. "You said I was talented! I've never had anyone call me talented before!"
The young boy swallowed. "Uh, wh-what -"
He couldn't manage to stutter another word before Toby interrupted him. "I realized something - my cardboard cutout of Shandra Jimenez was just getting in the way. I'm not with her anymore." He reached out, taking Dipper's hands into his own. The child's eyes shot wide open and he immediately worked up a nervous sweat. "I've decided I want to marry you!"
For a moment all was silent. Then Dipper squeaked, "Mabelhelpmeplease."
She burst into loud cackles in the background, doubling over and clutching her stomach.
"What do you say?" Toby asked hopefully. "Ha-cha-cha!"
Dipper gulped audibly. The Smile Dip. It had to be the Smile Dip. There was no other explanation. He frantically jerked his hands away from Toby's and slammed the door in his face. "I think - I'm gonna go to bed," he croaked.
Mabel laughed so hard that no sound came out of her mouth. Tears streamed down her bright red cheeks.
"Wait! No! Come back!" Toby's voice called desperately, muffled by the door. "I already announced our engagement in the Gravity Falls Gossiper!"
Dipper choked on nothing at all and collapsed to the floor in a crumpled little ball of purest horror. "No," he whispered to himself. "No. No no no nonono. It's okay. It's j-just - just the Smile Dip." He squeezed his eyes shut. "Yup. I'm just gonna go to sleep right here. Night, Mabel."
She didn't stop laughing for a full ten minutes.