Okay, so just to make sure some things are clear, in GF time this is right before Dipper and Mabel's birthday/growing up crisis and also AnE/BE events haven't happened yet, Rin knows what's happening and that he has to run but Shiro informs the twins that they are going to Gravity Falls Oregon instead of trying to send Rin off on his own subverting Shiro's death all together (for now, mwhahaha). I just have this show on my brain and decided that it needed more demons :D Also, Bill and Satan seem kinda similar to me, both all powerful demons that have the ability to posses people and have plans for invading the mortal plan, bringing two worlds together; add the insanity and blue fire and we're really getting somewhere...

*POV indicates a change in point of view

Chapter One: Exorcists are real?!

Dipper shifted in his bed, still groggy and sleep deprived from last night. He had been roused from blessed slumber by a very loud argument between Grunkle Stan and Grunkle Ford, not that they'd really sorted out all of their issues yet.

"And I told you, 'there's no way I'm going to let some religious crackpot anywhere near the kids!'" Stan snapped.

"How many times do I have to say this? Father Fujimoto is not a crackpot!" Dipper sat up and rubbed the sleep from his eyes, tip toeing down the stairs to eavesdrop better. Mable, who seemed to have just woke up as well, followed him silently. Neither of the twins needed to vocalize their intentions. "Bill is a demon, and my friend is the foremost expert in Exorcism and has a strong understanding of demonology; he can help us, the whole world in fact!"

"Look, I know you think this guy is legit, but I just can't trust anyone that deals with spirits and all that."

"Stanly, you mean well, but this is my house and my mission. I've already called him, he'll be here in a few hours."

"When! When did you call this Fujimoto guy, and why are you telling me about this now?"

"Would you have prefered I tell you nothing?!" Ford sighed deeply, "I called him three days ago, he phoned my back last night saying that he'd be here by this afternoon, if not earlier."

"What!" Grunkle Stan was furious. Before the argument could spiral further out of control the doorbell rang.

Dipper, possessed by curiosity and the need to meet one of Grunkle Ford's paranormal experts, rushed down the last few steps and yelled, "I'll get it!" to ensure his other Great Uncle didn't shoo their visitor away. When he opened the door the shadow of a tall man fell over him. He was clearly older, probably in his late sixties, and dressed in a long front-buttoned robe. The clerical collar denoting his relation to the catholic church. A small, white cross decorated either side of the white band. Two overlapping, long chain gold chains hung from his neck, from the shorter one dangled a pin. It had a long point to it that could probably be used as a stabbing weapon. It did look sharp.

Fujimoto's smile was gentle, but the red tinted reflection of his glasses (Think Hellsing: Alucard) was very unsettling. They were held in place by a decorated clip of some kind, off white crosses and a few beads hanging on either side of his face. "Ah, hello, I'm looking for Stanford Pines, is he home?" At least his voice was gentle enough to settle Dipper back down a bit.

"Shiro! Welcome, come in, come in!" Ford pulled the door further open from behind Dipper and placed his hand on Dipper's shoulder guiding him back. Stan glared and Mable glanced around nervously.

When the door closed behind the exorcist he plucked a box of cigarettes out of his pocket, "Hope you don't mind to much, Ford. I kicked the nasty habit a few years back but ever since my oldest grew up, he's become a little stressful to deal with."

"We all have our vices," Ford replied sincerely, "how are those two doing by the way?"

"Oh they're great kids, really, but I'm worried about Rin… He's got a temper, though he means well." He returned the pack to his pocket and chewed on the white chemical stick for a moment, seemingly lost in thought. "Twins," he muttered, "they're rampant these day, am I right?" He had a fatherly grin, and ruffled Dipper's hair, "First you, then these two…" His gaze had drifted from one face to another, the smile fading into a serious expression when he looked at Dipper again. The twelve year old felt his throat tighten, the question he'd been asked taking a long time to sink in. "Have you ever been possessed by a demon, son?"

Everyone stared wide-eyed at Fujimoto for a solid minute. Dipper shifted his vest, uncomfortable under his stare, "Y-yes."

"I see," the smile returned to his face, "I bet you'd think twice about making a contract with one of them now, hu?"

"Definitely!" The Father nodded in approval before turning to look at Ford, a mischievous smile plastered onto his face.

"Oh no, I know that look Shiro, there's no way I'm letting you whisk him away to Japan with you."

"Aw, but why not. He's got promise, I can tell. An exorcist serious about the mystery of the world is more than welcome in the True Cross Order." Grunkle Ford just stared, stern, prompting their guest to shrug in defeat. "Suit yourself," he muttered, snapping his fingers. A bright burst of fire lit the cigarette still between his teeth, "now, onto business, Demon proofing the property."

Ford sighed once, "This isn't going to be easy."

"Being an exorcist ain't easy either, Ford. If I wanted life to be easy I'd have been a lawyer." The adults all laughed, Mabel had just been examining the older man with narrowed eyes.

Dipper's twin finally belted out what had been on her mind, "What age?!"

"H-hu?"

"Your kids, how old are they?"

"Ah, well Rin and Yuki are both the same age actually, fifteen."

"Hmmm."

"A-anyway," to say Dipper was excited about learning just what skills Father Fujimoto had was an understatement. He wanted to keep this new mystery on track at all costs, "about demon-proofing the house?"

*POV

Wendy was hanging out with her friends in the mall. Her favourite 'rebellious teen' store, when the door swung open. Normally she wouldn't pay attention to such things but it was clearly an out-of-towner, "Dude, doesn't he know what store he's in?" she huffed in irritation. He didn't quite seem like he belonged, being dressed in a semi-formal suit and all. The teen had dark blue black hair and a slightly pale complexion. His hair was a mess, sticking out all over the place, it kept falling in his face. When he flicked the stray hair out of his eyes, she realized just how impossibly blue they were, like the sky, and they seemed to almost be glowing.

"He's actually kinda cute," one of her female friends leaned over to follow her gaze, "y'know if he wasn't dressed like a stiff."

Wendy couldn't take her eyes off of him, there was just something so, so...unnatural about him. He was looking at clothes, and after picking out some walked back into a changing room. To get there he'd have to pass the group, and with her gaze glued to him all the other teens immediately teased her about having a crush. She was finally able to look away, turning red at all their gibes. "I-I don't have a crush on him! It's just that he's clearly not from around here… the way he's dressed is weird and it's not that he's-" she was cut off by the teen's reemergence, that was fast actually. He had ripped jeans, a black skull shirt, and an unzipped, off white hoodie. Wendy just finished lamely, kinda shell shocked about how much a simple change had altered his presence, "-hot…"

The cashier also noticed the difference, as did everyone else. The blue eyed boy was suddenly dangerous and charismatic. It was clear that the he'd been just as uncomfortable in the suit as he had looked. "Mind if I wear these out?" the voice was so smooth!

The attendant visibly blushed, "S-sure! Here let me get those… uh… tags."

"Thanks," he turned to let the tags be cut out and their eyes met. Wendy just stared, mouth slightly open, pink hinting at her cheeks. There was something seriously wrong with her brain, cause it sure wasn't working right now. She decided he had to be some supernatural something or other when he smiled at her, his fang-like canine teeth made that much clear.

"I gotta go guys," Wendy said, her mind snapping back into serious mode. Her friends didn't seem to understand however as they gave her cat calls and encouragements in her 'obvious romantic interest'.

She had just caught up with him as he left the store, mildly amazed at how much ground he'd covered. "Wait! I need to talk to you," he didn't seem to hear her, or even notice her existence. A growl of frustration escaped her lips and she seized his arm, "Just hold up a second!" she snapped. He stopped dead in his tracks, turning his head only enough that she could see his eyes.

All her worries were confirmed in the span of three words, "Let go human." His pupils were glowing orange slits and the ires that surrounded them were warped. Her fingers unlatched causing her arm to fall limply to her side. "Wha-"

"Nii-san!" Faster than his eyes had changed into their current state they shifted back. Another teenager, only slightly less strange, and very similar in appearance called over to the boy Wendy was talking to. The new one had lighter hair, clearly brown, wore glasses framing his teal eyes, and was dressed in some kind of combat jacket. On the whole he seemed to be the same age, just more mature. There was the same odd feeling that the darker haired one had caused earlier, only less powerful.

"Yukio," the boy in front of Wendy said with mild irritation.

"What are you doing wasting time here? We should have been at Mr. Pines' home half an hour ago. Father is likely already working."

"Humph, you're the exorcist, Yuki~," the glasses one seemed to be pissed off by what was likely a nickname, "I just got dragged along on your crazy demon hunt. I don't even believe in all that supernatural crap anyway."

The one named Yukio sighed, "Okay then do you at least have the map?"

"Uh…" he was feeling around in his clothes, "shit…."

"RIN!"

The two sounded like a bickering like an old married couple and Wendy just had to laugh. She couldn't believe that she'd actually been afraid of this Rin person a few seconds ago. He seemed like a 'rough around the edges' guy, sure but he was the typical teenager after all, even if there was something off about him. "Ugh...hehe...I-I'm sorry, it's just that...hehehe...ah, I actually work at the Mystery Shack where Stan Pines lives. I can take you there if you want."

"Uh, thank you, miss…?"

"Wendy, just Wendy."

"Do we have to?" the dark haired one, who was just a hair shorter muttered.

*POV

Dipper was mixing some weird plants together under the joint supervision of Ford and Shiro, the two older men discussing the antics they used to get into during a brief cooperation a few years back. The main focus was on a succubus that tried to deceive Ford and how the she-demon reacted to having Shiro, quite literally, breaking down her door with her incubus boyfriend behind him. Mabel and Stan had been listening intently, seemingly curious about the adventure, while Dipper was full of questions like how Shiro had been able to identify the succubus without being seduced by it and the best way to protect yourself from demon possession.

The young paranormal enthusiast was just about to off load some of his thoughts when Wendy's scream punctuated the air. They all seized their work and sprinted to the front door. Three teens, one in a combat jacket, the same pin that Fujimoto wore affixed to the dark cloth, Wendy was in the center, and running behind and to her right was another boy with dark hair and a grey hoodie. "This is why I said not to leave the path!" Wendy shouted to the others.

"We didn't!" the cloaked one bit back.

"Oh, to hell with this," The one bringing up the rear suddenly wheeled around to face the forest, "Alright ugly, you wanna pick a fight with me? Hu!? Come get some!" Just as he finished the trees parted and snapped, a large purple rhino-like monster tore through the undergrowth, spitting mad. The other boy had stopped a look of horror on his face when he realized what was going on. Wendy also stopped but she was slower on the uptake.

"Rin!" Shiro roared, somewhere between terrified and really pissed.

"Hey, Yuki," the boy who must have been Shiro's problem son called over his shoulder, "don't worry, this time I'll use my head."

"R-rin what are you-" The beast had fixed its' eyes on Rin before the other could finish. The two charged at each other and Dipper was sure the poor guy was going to get flattened. He could feel the impact from where he was standing, a shock wave sending a rush of wind out. Rin's shoulders were braced, his entire body in fact had been postured perfectly to absorb the g-force. What surprised Dipper was the rhino-thing's legs going limp as it crumpled, out cold from the collision. "What the fu...H-he...he…." Yukio at first was to astonished to say anything but soon dropped to his knees in an uncontrollable laughing fit, "R-Rin you d-dumbass...hahahaha! 'Use your head'? Pftt...haha. What a brother!"

Dipper, slack jawed, stared up at Shiro. The man was clearly not as amused, no where near amused. He sighed actually, like a father who is too proud to be disappointed, it was a weird sigh. "Rin, you trouble maker," he muttered under his breath. Mabel on the other had gasped and her brother could swear her pupils had turned into cartoon hearts. She had found her crush for the week, just great.

Once all of them were inside both Yukio and Shiro ganged up on Rin who was sitting on the floor just accepting the harsh verbal reprimanding. It was clear the the taller of the two brother was copying his father, from the way they dressed and even small mannerisms like adjusting their glasses. Mabel just adored it but Dipper found it a little creepy. "Do you at least still have the key," Shiro said, finally calm enough to speak at a reasonable volume, effectively springing another five hundred questions into Dipper's head.

"Of course I have the key!" Rin lifted a stylized gold key from under his shirt, it was on a chain around his neck, before tucking it back into his clothes. "Like I'd lose something that important," he muttered, seemingly dejected.

*POV

Unbeknownst to everyone in the pines residence a spy of supernatural origin had been watching them from another dimension. "Hmm, this could be interesting," Bill announced to no one in particular, "So the Pines have erected a barrier to prevent me from accessing the house. No matter if I can't have a pawn on the inside," his voice distorted and the images of many different people flashed in his eye, "I'll have to find one on the outside."

The dream demon froze, something didn't feel right, like there was another powerful demon observing the situation, one that could get though even though he couldn't. "Who..is THAT!?" When searching for a face all that unveiled itself about his visitor was a single ember of blue flames, not of the kind he used. No those little sulfuric sparks couldn't hold up a candle to this blaze. "Satan…"

"It's been awhile, hasn't it, Cipher?"

Dun Dun Dun... I have no idea if I'm going to keep writing this... I dunno. Maybe I'll drag reverse!Dipper into this...I feel like that would be fun.