A/N Hello everybody. This is my first Gravity Falls fic and my first horror fic ever so I don't know if I made it right, I'm not the best at horror so for many people, it may be lame. I hope that I made it good and that you'll like it. Before starting, I want to tell you that my English is not perfect since it's not my first language. Enjoy that story A/N

Dipper Pines was a twelve years old boy, spending the summer at his Great uncle's house, the Mystery Shack in Gravity Falls, Oregon together with his twin sister Mabel. At first glance, they seamed like ordinary children that lived an ordinary life, and they were... sort of. The first part were true, they were average children from an average family of two children, and spending the summer with their money addicted grunkle seemed normal (kind of) and for them, their summer was completely normal, but for most people, it wouldn't be. The twins always got involved in the supernatural of the town. They had seen a lot of things that most people wouldn't believe, everything from gnomes and a multiheaded bear to cursed wax figures to a demon shaped like a triangle, they even raised the dead at one point, or correctly, Dipper did. You see, unnatural stuff almost everyone, normal for them. Since it was normal, they knew how to react to everything and they weren't afraid because they always knew what to do because of the journal, but the journal wouldn't have and answer for anything that would happen today...

It all started on a Friday morning in the middle of July. Grunkle Stan was on a trip to Portland, buying fake gold to sell to the tourist and therefore, the Mystery Shack was closed for the day. Mabel was going to town with her friends Grenda and Candy to buy a new iguana for Grenda (her other one was lonely). Therefore, Dipper would be alone for about two or three hours, he didn't complain though. Being alone meant that he could one of his horror books, something he could never do when Mabel was home since he always read aloud without noticing it and Mabel didn't like when he read horror stories aloud. She wasn't afraid or anything like that, but she thought that those were the most annoying stories that he read.

"Goodbye bro-bro. See you later", Mabel said as he left and Dipper smiled.

Finally alone, finally time for horror stories. It had been a long time since Mabel was out and he wanted to know the end of a book called "Shadow?" so he rushed up to the attic, took the book and started to read. The book was about a middle aged man that killed his son because he became mad when his wife died in a coma. He lived with his five years old twin daughters like nothing happened (the police never suspected him for killing his son) and when he didn't show up at his son's funeral, strange things started to happen at the same day. Days flew by and turned into weeks and then, everything became extra surreal and creepy. He felt followed a lot more then before and the screams from a child could be herd, and at the end, he was running from a shadow that made it unable for him to leave the house with his daughters. When it was only two sides left, he left the room to get a little water and went back to bed, putting the almost full glass on the small table beside his bed and started to read;

The cries of the child grew louder and louder and Jim and to put his hands on his ears to not faint. The twins hugged each other and also started to cry and their cries replaced the cry of the shadow.

"Daddy, I don't like it here", Tiffany said with tears in her eyes. Jim looked over to Vanessa and she just stared at the wall.

"Daddy, let us out of here. The shadow is scary", she said and hugged her sister again. Jim's heart started to beat faster again, they had been trapped for about two hours already and he was tired and suspicious. The feeling of being watched, the feeling that he was in grave danger grew again. It was only a matter of time before the shadow came again, again for revenge.

"DADDY!", Vanessa suddenly screamed screamed and pointed at the wall were the black shadow with white dead eyes stared at them before reaching out one of its arms, it grew unnaturally long and the cold and bony fingers were only about an inch or two from the face of Tiffany. The finger looked like knives, sharp knives. He took his children, Vanessa on his back and Tiffany in his arms and ran up for the stairs but the arms of the shadow grew longer and the stairs got longer and longer and suddenly, from nowhere, he could her something dripping. He looked up in the ceiling and saw his daughters lifeless body. Vanessa was no longer in his arms, she hang from a black rope and blood was dripping from her face, her skin was no longer there. As he finally made it up to the last step with a screaming Tiffany, the eyeballs of his daughter fell down on his face and he felt disgusted. He tried to make it to the bathroom, he could jump out of the window and run away. He heard the shadow again, but this time, it didn't scream. It laughed.

"You're going to die. You and the remaining twin", it said and the voice felt familiar. The shadow was suddenly in front of him and he could feel a sharp pain in his stomach and he heard Tiffany's scream. The shadow held his daughter in the hair and used his sharp fingers as knives to cut of her scalp. The last thing he heard was his daughter screaming and the shadow laughing. He knew who it was. It was his son who wanted revenge on him because he let the twins live. And...

Dipper sighed. What a lame ending. The book had been so good but had been ruined. The last sentence wasn't even finished, it was pathetic. He putted the book away and was going to drink little of his water when he realized, the glass was empty. Didn't he bring a new glass up? Yes he did, but he found a logical explanation, while he read he must been to carried away by the book that he forgot that he drank up the water. He nodded, that was the right answer. He went down to the kitchen again and took a new glass of water before getting up to his room. When he entered he saw that a book had fallen out of his bookshelf. He putted the glass of water down on the table and took the book in his hands.

It was the book about the shadow...

He sighed, it was normal for books to fall out of bookshelves, nothing was out of the ordinary and he didn't give the thought another second. He sat down and started to read a new book, about a serial killer that followed innocent children. He read and when it was only about ten pages left, he heard a scream from a child.

He shouted and jumped up, dropped the book and looked around him. He sighed, imagination. There was no way that someone screamed, he was just scaring himself. He looked at the book, but he didn't want to read anymore, he just had a strange feeling even though he didn't admit it, and he was tired of reading. He was going to finish the book later. As he was going to drink the water, he saw that it was gone again.

"Wow, I really get distracted when I'm reading", he said, thinking logical. After all, Mabel always said that too, but the bugging feeling in his stomach grew a little. He sighed again, maybe some tv would calm him down. He sat down in the armchair usually used by Grunkle Stan, took the remote and turned on the tv that was playing Duck Detective. He watched tv for about two hours and looked at the clock. Mabel left the house five hours ago...

When was she coming back, and were was Grunkle Stan?

The news suddenly turned on and he saw Stan on tv, he had been shoplifting fake gold and was under arrest. Dipper sighed, he would be home late again, running away from the prison in Portland was harder then in Gravity Falls, but at least he didn't need to worry about where he were, even though they would get late breakfast.

On the other hand, he still didn't know where Mabel was...

She usually came home later then normal, but this was too later even for her. The strange feeling that had disappeared was suddenly back again Dipper bit his lip without thinking. Why did he do that by the way? He sighed and tried to think of a logical explanation, maybe she went to town to buy something to Waddles, or maybe she had started a random sing-along party in the middle of the town again. He nodded, yes that was the answer. It wasn't that late anyway, only five in the afternoon, so he wouldn't need to worry for a few hours. He went out of the living room to the kitchen to make some food for himself, and after eating his unhealthy but tasty microwaved pizza he went back into the living room and as soon as he saw it, he stopped and just stared at it.

The glass from his room was laying on the carpet, and instead of clear water, a red liquid was spilled on it. He bit his lip again and just stared at the sight as his body was shaking. Now he was scared, this time, he knew that he left the glass in his room and that is was empty when he left. Someone had to be in the house, how else could the glass be laying on the carpet together with the red liquid.

What was that liquid anyway?

He shivered, thinking the worst.

Blood.

Could it be blood? He didn't know but he certainly hoped that it wasn't. Mabel had a painter set with all kinds of colors and red was one of them after all, but thinking that the liquid was paint didn't really convince him. He broke out of shook and started to think of logical solutions, maybe Waddles played with Mabel's things and brought down the glass? The theory was good but had one problem, he hadn't seen Waddles all day. The other theory was the he spilled a glass of strawberry juice on the carpet without even remembering it, no he did not believe in the one. Then it must be a monster. Many would say that it was thoughts of a children, but Dipper knew better, monsters were real. He knew that it couldn't be the Hide-behind since it only stalked people, it didn't mess with their lives. The gnomes would be to noisy and the lilliputians were trapped in the golf course. He took out is journal and tried to find something, it was better to be early prepared, who knows what the monsters next move is.

"Dipper Pines...".

The voice was quite and it only existed in his head. It was a voice of a young boy and the voice of a grown man mixed together. The grown mans voice felt familiar somehow, he didn't know why, but one thing was clear, it gave him creeps.

"Twins...".

Their the voice was again. The first sentence gave him creeps, but this one made him terrified. It sad twins, which meant him and Mabel.

Oh no, Mabel. What would happen when she got home.

"Show yourself!", Dipper shouted as he was trembling. If he saw the body of the monster, he would maybe be able to defeat it. He heard a laugh, a laugh so high and low, so cold and warm and so terrifying at the same time that it felt like it twisted reality, turned it upside down. The laugh ceased as fast as it came, and Dipper then felt like somebody was watching him, right behind him. He quickly turned around because of his instinct and stared at the wall. From nowhere, blood was added to the wall, making a sentence.

Why would I?

He wanted to scream but was to afraid to let it out. Now he knew that he wasn't alone, he knew that he wasn't making things up.

And that was the whole problem...

He knew.

Dipper ran out of the room in fear, locking himself in the bathroom.

Bad idea.

Only two minutes later, blood started to appear on the mirror, making a new sentence.

You can never hide...

He gulped. In his reflection, he saw to almost invisible hands on his shoulders that weren't there in real life. He let out a scream and ran to the living room, trying to make it to the door, but to no use. As he held the doorknob, he felt like his hand was going to burn off and he fell to the ground.

"Don't leave so quickly, the party is not near from over...".

The voice echoed in his head and almost made him throw up. The voice was just to high for him to handle. Without thinking, he bit his lips again as he kept his fingers crossed.

The journal, if only he had enough time to look this monster up in the journal...

He knew it wouldn't work, if the monster followed him so close like it did now, he would never get the chance, and he would be dead.

"Dead, I like the thinking...".

The voice was back and this time it really made him throw up. Half-digested pizza was laying on the ground and Dipper tried to stand up, but the terrifying voice made him to weak, made him feel sick, and worst of all, the monster could hear his thoughts. He jumped up and started to run around the house again, and the same routine followed, he ran away, bumped into something, either got a message in blood on a wall or hearing the voice in his head. It was a game of cat and mouse and as Dipper ran for his life, he forgot the time.

Suddenly, the phone rang but Dipper couldn't answer, as something new happened. He could feel something warm on him, it felt like a liquid... He saw himself in the mirror, blood was dropping from the ceiling and on to him. He shivered and screamed because the blood became hotter and hotter, like the doorknob...

The phone went quite and he could hear a message.

"Hey bro-bro! I'm going to stay at Grenda's together with Candy. We're going to marry her two iguanas. See you tomorrow".

Dipper sighed in relief, and fear. The monster wouldn't get Mabel and that was good, but it would get him eventually and his sister would still get home tomorrow. Right now, the monster were only playing with him to make him scared, and it worked. This was the scariest thing that ever happened to him, even scarier then when he met the gnomes for the first time, when he met Bill and even when he raised the dead. As the blood cooling down, Dipper scream faded away and he could move again. He had been running around on the lower floor all this time, and it looked like something from a horror movie.

Blood and destroyed things everywhere...

He knew that this probably was a bad idea, but he ran up to the second story of the house, because who knew if he would be able to find something to defeat the monster with. He ran up with all his powers, not thinking about the consequence about it as he screamed.

He was tired of it!

Tired of it all...

Why would the monster chase him like that, and for so long when it could easily end his life?

"To make you insane...".

The voice made him fall to the floor and he quickly putted his hands at on his ears. The voice was so strong and terrifying. He would have thrown up, but his stomach was empty. The voice disappeared and Dipper stood up, feeling the pain in his knees, it felt like knives were cutting them off. Blood was running down from them, to soon touch to ground. When he felt, the knees were the first thing to touch the ground. He knew it would happen eventually and was actually surprised that it took so long before hurting himself. He tried to run, it worked but he couldn't run as fast as before, it hurt to much.

"Aaaaaaaaaaaaah!".

Dipper held his hands on the ears again, the monster were screaming, and this was absolutely the worst scream so far. Without realizing it, he sat down in the ground and started to cry. He didn't want all this, why did it happen to him? Why did the creature do this to him? He blinked and...

"Aaaaaaaaaaaaah!". He saw it. Only about five or six inches from his face stood a black figure of bones and mist, it was between six and seven feet high and the face was a rotting black cranium with red eyes. The whole creature was transparent and it looked like it was smiling as drops of crimson blood fell to the floor from it's fingers sharp as knives.

It was the shadow...

The shadow from the book...

Dipper screamed and the shadow smiled and next second, Dipper could feel the fingers on his shoulders. He blinked and next second... he were somewhere else...

Instead of being near the door to the attic, he was in a small black room without any windows and doors.

Was he dead?

He stood up, the room was so small so that he could only take a few steps in it, and that made him insane. The claustrophobia took over and he sat down and cried as he bit his lips again. He wanted to get out of there, and he would do anything.

"OUT, OUT OUT! PLEASE LET ME OUT!", he screamed as he banged on the black walls the hardest he could, and only a few minutes later, blood was streaming down his knuckles.

"You alone are not interesting, you'll have to wait here before the other one is here...", the voice of the shadow said and Dipper fell again, knocking his head in the wall on the way.

It hurt like hell and he was terrified, but when the headache disappeared, he started to beat on the walls again, even though it hurt, the fear made him to continue. He needed to get out of there, he needed to defeat the shadow before Mabel came home.

Mabel...

If she came home, they would both be dead, he needed to find something in the journal. He sat down and opened the book and quickly looked in the book as he continued to cry. All the pages became red by his blood and got wet by his tears, but he couldn't find anything, the shadow was a creature from a book after all, but if it only was that, HOW did it come to life?

"Aaaaaaaaah!".

He screamed as something fell down and landed on the ground. It was a book, covered in blood. He opened it and red a page on the bloody paper. It was hard, but he figured out that it was the book about the shadow. But why did he get the book right now? Was it because he asked for it or...? He quickly opened the last page of the book, and he saw that it was more text then before. It read;

It was his son who wanted revenge on him because he let the twins live. And because of that, he would delete the memories of twins from the world, he would kill every pair of twins that ever existed so that no one would remember that twins existed, and he would start with the Pine twins...

Dipper screamed again as he threw the book away, and even though it only was two feet away from him, it felt better without the book in his hands. He waited there in agony and pain for several hours and would periodically start banging the walls again, but to no use. As time passed, he became more paranoid, and at the very end, he rocked his body back and forth as he whispered;

"Not my sister, not my sister, not my sister", to himself.

Suddenly, he was falling and felt the hard floor that belonged to the Mystery Shack, he was beside the door to the attic, were he was before.

He knew what was going to happen as he heard the door downstairs open.

"Hello bro-bro, I'm back! I heard that Grunkle Stan is in Portland and AAAAAAAH!".

"MABEL!", Dipper screamed as he ran down the stairs, waiting for the worst, and that was what he got. He saw her lifeless body, hanging in the ceiling near the door, with a blood dripping black rope around her neck. Beside her was the shadow and the laugh began again. He watched in horror as the shadow used its fingers to cut off her scalp and it was then he realized.

It was exactly like in the book, and this was the way that all the twins were going to die...

Seeing it in real life made him realize that it wasn't a pathetic ending, but a horrible one. The scream of the shadow got replaced with his own and he was so scared that he didn't notice the hands on his shoulders. He fell to the ground and could feel the shadows hands as he got the black rope around his neck. The last thing he saw was the book about the shadow and that the authors name changes. It was no longer Anthony Martin.

It was Bill Cipher.

And with that, everything went black.

A/N That was the story. Did you like it or not? Please leave a review and tell me if you thought that the story was scary or lame. A/N