A/N: This chapter was originally going to contain more of Dipper and Mabel but it got too long winded and didn't feel like it flowed without a break so it's been shortened. Also As a side note, the time lines may not match up like they would, aka supernatural season 4 taking place in 2008/9 and gravity falls in 2012 but uhm... I don't care, the characters and how I want the story to function means these are the perfect moments for them so that's why event's are taking place when they are.

Chapter 1: Where Everything is Wrong

Mabel was acting weird.

Not her usual Mabel weirdness but actual suspicious weirdness. If the barrier hadn't been in place and he hadn't been assured by Ford that it would keep Bill out, Dipper might have thought his sister to be possessed. But day in and day out she came and went form the shack without hindrance.

It all started after their argument, and Mabel ran off into the woods. Thank goodness she hadn't grabbed his bag with the rift in it. That could have been catastrophic if it had accidentally smashed or any other number of things that could have gone wrong. Just thinking back on it made Dipper start to breathe heavily.

Luckily that didn't happen, Dipper was able to hand the rift over to Ford and let him seal it thus saving the world. Yet as things progressed Dipper worried about his sister who had yet to come back. It wasn't until late at night in the darkness that Mabel came back, cool as a cucumber and covered in twigs and grass stains acting like nothing had happened.

Dipper had been wanting to apologize. He had been agonizing over running his sister out, for their fight, for accepting Ford's proposal without really thinking about what it would do to his relationship with Mabel. So when she walked in, he sputtered out a hasty apology, all she did was smile at him and give him an, "it's okay bro." And promptly went to her bed and passed out.

To say he was flabbergasted was an understatement. He just gaped at his twin as her breathing evened out. That wasn't... normal. Over the next couple days she would continue to be not normal. No Mabel juice, no glitter, no spontaneous tackle hugs. When he confronted her about it she just told him that she was trying to grow up and be more mature. When he asked his grunkles about it Stan seemed distracted by his own problems and told him she was probably just having 'woman trouble' and Ford suspected that she was just giving him some space to be on his own. It was weird for both his great uncles to agree that nothing was wrong and not notice his sisters sudden change.

Over night his sister had become a total stranger.

It got so bad that on one sleepless night, filled with paranoia and self doubt, when he heard his sister move he knew something was up. It had to be at least two in the morning. The thought crossed his mind that maybe it was a nightmare but he didn't hold out hope that it was the case.

Mabel shifted some more before sitting up and getting out of bed. Dipper froze for a moment, closing his eyes and pretending to sleep. He wasn't sure why but he felt the need to stay still, a certain dread raced down his spine as he heard her make her way to the door and down the stairs.

After a moment Dipper decided to follow her and tried to stealth his way down the stairs after her, avoiding the creakiest boards on the floor. He stopped just outside the kitchen hearing her rummage around. Briefly he had a flash of Bill taking him over and shoving his hand into the utensil drawer. The memory caused brief phantom pains along his arm that made the hair on his neck stand on end. With a shaky breath, he forced down the memory and looked into the room... only for his heart to stutter as he saw his sister with a large knife.

Mabel was looking at it admiringly with a dopey smile on her face. The knife glinted malevolently in the moonlight seeping through the kitchen window and Dippers immediate thought was to take it away from her and demand an explanation. Yet instinct told him not to be noticed, that there was something sinister and dark afoot. His heart was hammering and he sincerely hoped that she wouldn't be able to hear it.

As Mabel came closer, he heard her humming some identifiable tune as he pressed himself into the shadows of the door frame. When she passed, he refused to move and inch as she proceeded to make her way out the front door. She once again left without the barrier activating and Dipper heard the faint shuffle of feet on grass get farther and farther away.

Letting out a breath he didn't realize he held, Dipper waited for a few moments, trying to decide if it was best to follow his strange acting sister into the dark creepy woods in the middle of the night or not. Part of him wanted to get Ford but another part told him that if he didn't follow her now, he might not be able to find her again and Dipper had to know what was going on with his estranged sister.

Decision made, as swiftly as he could and without making much noise, Dipper Pines left the safety of the shack and stole into the night.

xxXXxx

"Come on Sammy, stop dragging ass." Dean groused as he hauled one of the (many) bags of weapons they had into the seedy motel room. The sultry red tones of the bed linen's contrasted heavily with the dark walls making everything seem somehow even dirtier and more ominous.

It was a couple days after the whole Adam incident and the boys were still getting over the shock of John Winchester having another son. So to cope in the meantime they would do what they did best, and that was hunt. They had a few possible monsters and one ghost they could go after in the nearby area, all they had to do was pick one and go after it.

At least that was the plan, but Winchester's should always know that their plans never go how they expect.

"Yeah, Dean, I'm coming-" Sam cut off as he walked in the door and saw his brother standing strait as a board. Looking around, he found the source of Dean's discomfort in the form of the angel Castiel who was looking at the hunter with an unfathomable expression. Both hunters were quick in showing their displeasure for their heavenly company.

"What the hell do you want?" Dean demanded, his hand itching to grab the gun on in his pants despite knowing that it would do nothing against the holy messenger.

"We have intel that Lillith is planning on breaking another seal." Replied the angel gruffly, getting right to the point. The angel's face remained as impassive as ever despite the grim news.

"Great, why don't you go stop it? Why make us go and get it?" Sam pipped up, getting as annoyed as his brother about getting pushed around by these dick's. They were not the angel's lap dog that would just jump when they said so. Yet somehow they always ended up doing exactly what the bastards wanted anyway.

"We can't." Castiel replied not bothering to take his eyes off Dean. If Sam was honest with himself, it was incredibly creepy how focused the angel was on his brother.

"Why the hell not?" Demanded Dean who looked ready to either storm out of the room or throw a punch.

"The place they are going to break the seal is somewhere angels cannot tread, otherwise we would try to stop it ourselves. We don't have much time, the seals are breaking faster than we predicted and this is one of the last few Lillith needs to open Lucifer's cage."

Well that was shitty news. The Winchester's knew that it was coming down to the wire and that the end couldn't be much farther now but still, they had hoped they would have more time. It seemed that they had been on the loosing side of this war from the very beginning.

"Cannot tread, what does that even mean?" Dean asked petulantly.

Castiel was looking uncomfortable for the first time during the conversation. The Angel reached up and rubbed the back of his neck awkwardly before sighing.

"A barrier protects the town where the seal is located. Angels cannot pass through it." Cas started, not looking at either of the hunters. "It is a place for gods rejected creations. Weird species that were never meant to see the light of day reside there. It is a... wild life preserve if you will for the weird and unholy."

Sam and Dean exchanged a glance at the information. That was new, they hadn't realized a place like that existed. They fought weird and deadly on a regular basis but an entire town of nothing but god's rejects? Sounded like a bad tv show if you asked them.

"Where is this place?" Sam finally asked and the angels laser like focus finally honed in on him.

"Gravity Falls, Oregon."

"Wait a second," Dean cut in. "You mean to tell me that an entire town of monsters is just sitting in the middle of no where Oregon?"

"Yes Dean, that is what I'm saying." Castiel's tone indicated that his patience was wearing thin dealing with them which was okay because the boys were fed up with talking to the angel the second he opened his mouth. "You must go and stop the seal from breaking."

"What even is the seal? A sacrifice? A summoning?" Sam chirped, hoping for more than just vague information. The angel grew quiet again and Sam wanted to smash his head against the wall in frustration.

"Well that's just great," Dean growled, "You want us to go half way across the country into a possible monster nest and you don't even know what we are looking for."

"We cannot see into the town either, it is cut off from heaven." Castiel tried to defend himself and his superiors. "The demon we got the information from wasn't high in command and could only tell us that there we big plans at Gravity Falls."

Sam knew Dean was on the verge of telling Cas to shove the whole seal business up his ass when the Angel was suddenly in front of his brother.

"There are few seals left, if you have any desire to stop Lucifer from rising, you will do as I ask." The angel with obvious personal space issues muttered darkly.

Dean stared at the angel but before either of them could blink the holy messenger was gone in a gust of wind. Neither brother said anything for a long moment, both contemplating the information in their own way.

"We're not actually going to go are we Dean?" Sam finally asked tentatively.

"You got a better Idea?" Dean rebutted, though it was clear he wasn't happy about the situation anymore than Sam was... But if demons were invading a town that was going to mean deaths and lots of them. Who knew what breaking the seal could entail, but they couldn't let innocent people die just because they couldn't stand the bastards up in heaven. Even if the people there were so called 'god's rejects', whatever that meant. With a sigh Sam shook his head and Dean just nodded in return.

"Alright, guess we're going to Oregon."