The pine trees blended into a blur of darkened green.

Gideon's legs began to burn as he used the last of his adrenaline-fueled energy to sprint again. The woods seemed never-ending, which made no sense since he never strayed from the trail. He felt blood rush to his face, all over his body he felt his blood race. There was no way he could go this fast for much longer, but he was terrified. Whoever those two people out there were, they were looking for the book and they knew he was there.

"Where are they, Mabel?" Dipper asked, his amulet in a brilliant green incandescence. "Perhaps we should give them a little reminder that things often go bump in the night."

"Maybe if we levitate over the trees, we can find our new friend faster?"

"Ah, brilliant idea, Mabel! If only I had thought of it first." He grinned smugly as they rose into the air, outlined in their magic glow.

Gideon could see the lights of the Mystery Shack as reached the clearing, he sighed in relief as he slowed his pace. He jogged up to the Mystery Shack porch, his heart still racing. The book was still clutched feverishly under his arm.

Mabel glided over the tops of the pine trees with a frenzied expression growing quickly across her face.

"Hmmm, I don't see anyone." Mabel frowned, looking over the abundance of forest.

"Ah, forget about them. Probably just some lost tourist or what not," Something caught Dipper's eye. "Mabel!"

"What."

"Mabel, come over here I found something!" He lowered back to the ground, in front of his feet was a large square opening in the middle of the forest floor.

Mabel lowered to the ground beside her brother. She placed her hands on her knees and leaned over to peer into the opening. She looked behind her at the tree behind them. She walked over and examined it.

"Dipper," She waved him over. "Look.

Dipper let out a shallow breath and followed Mabel over to the tree, using the glow of his amulet to light up the path. He stood by his sister, amulet in his hand and noticed the opening.

"What the-" He elbowed his sister out of the way to get a better look at the opening.

"OUCH! Dipper, you're such a prick!"

"No..." Ignoring his sister's comment, he lit up the opening. A small cracked metal box was all there was to see.

He pressed the buttons frantically, nothing. He flipped the first switch, nothing. He flipped the second switch, a mechanic whirr cause Dipper to turn.

The opening closed up.

"Let me look!" Mabel shoved her brother away. She flicked the switch again. The opening appeared. She walked back to the opening and kneeled to look down into it. There was nothing except a mess of cobwebs, dirt, and a thick layer of dust. All with the exception of the large rectangular outline in the middle. Mabel felt her heart drop into the pit of her stomach.

"Oh no..." Mabel stood up quickly, brushing the dirt from her knees.

"What is it?" Dipper turned for the odd machine in the tree trunk. "Did you find something?"

"No," Mabel felt herself grown cold, she felt sick. "Worse. I didn't find anything. But.."

"No."

"I think someone else found the book."

"No!" Dipper gave his sister a hard shove before running back to the opening. Mabel's back slammed against the hard dirt ground, her breath expelling as she let out another yelp.

"Shit!" Dipper lit up the opening, nothing but the book outline. He turned back to Mabel. "Get up."

Mabel sat defiantly on the ground, angry at her brother's sudden rashness. He can have such mood swings sometimes, it was irritating.

"Mabel, someone has the third book," He brother leaned over her. "We have to find them."

"It was probably that person I sensed earlier," Mabel huffed, crossing her arms. "If you hadn't stopped us, we could have caught them and the book would have been ours!" Mabel rose to her feet, her face tinted crimson. The sun was just about gone and soon only the moon would provide them light. Her amulet illuminated her look of disgust vibrantly.

"You're always trying to take the lead! She jabbed her finger in Dipper's chest accusingly. "You're always making the decisions! And you think you can just push me around because you're mad that we failed and that you couldn't please the spirits by finding the damn book! But if you had just listened to me for one goddamn minute-"

She was surrounded in a glow and levitated into the air by her brother.

"Mabel, calm down. I can fix all of this, you're being irrational." He said, evening his tone with some difficulty. He held the amulet tightly in his hand.

Mabel grabbed her amulet and broke from the aura holding her, she floated up to one of the higher branches of a nearby pine tree and sat.

"There you go again, Dipper. 'I can fix all this, you're being irrational.' Do you know how stupid and controlling you sound?" She crossed her legs. "I'm so tired of it. We're twins, I am not your little sister, you do not have to look after me." Her eyes narrowed as she finished her sentence.

Dipper felt his face grow warm, this was just absurd. He let out a sigh before looking up at his sister who was swinging her legs playfully off of the tree branch.

"Yes, I do!" He called up furiously. "You're unstable on your own! You need me to keep you in line. In fact, if it wasn't for me you would have been caught and sent to an asylum by now! You think you can handle these things on your own but you can't and I know you can't!

"You're disgusting." She spat back at him. "Let's remember who actually found the book in these woods four years ago. Who was that? Oh, right it was ME!" She floated down onto the forest floor, her green vapors swirling behind her, aggravated.

"Don't make me laugh, you didn't even know what to do with that book!" Dipper seethed, venom in his voice. "You know why, Mabel? Cause you're stupid! You're a complete idiot! And worst of all, dear, darling sister of mine, is that you are a coward!"

He felt a force grasp him and quick whip of his sister's hand and he felt himself being thrown into the tree trunk. His back slammed against the trunk of the tree forcefully. His head hit the hard metal and sent pain shooting quickly down his spine. He let out a moan before refocusing on his sister still standing in front of him.

"I am not stupid, Dipper," She said, releasing the aura surrounding him. "And I am not a coward." Her voice softened, lowering her head. There was hurt in her tone. She looked back at him, her eyes sharp, poisonous, and piercing in their blue radiance.

"And I am going to find that book without any help from you. Then we'll see who the real idiot around here is." Her voice faltered before turning her back and heading along the trail.

Dipper stared after his sister. He could pull her back and slam her against the tree trunk as well, and he wanted to. But he knew, though he hated to admit it to himself, that his sister was more ruthless than he could ever dream to be. She was emotional, reckless, and demented. And at the same time, she was still the same sister from four years ago. The same one that left a mess of glue and glitter on the living room floor and that played her pop music so loud that the neighbors would complain. She was still Mabel, but she had evolved. As well as him, she had learned to adapt to their new, and in his opinion, better situation. He couldn't help but envy her, keeping her character after everything they had been through. Though, she was much more crazed, psychotic, and deranged than she was at twelve years, he knew she hadn't changed as much as him.

As for him, he liked to consider himself enlightened. Yes, he had modified much more than Mabel had, but he considered it more of a challenge. Anything to prove himself, anything to show how strong he could be. It was wonderful, discovering all the mystical secrets of this town alone. And had Mabel also forgotten who came up with the idea for the Tent of Telepathy? Well, it definitely wasn't her. Dipper knew his sister had no chance in finding that book and now that she wasn't holding him back, he was going to find it a lot faster.

He rose to his feet slowly, pain shot down his neck. He let out another grunt before straightening up, returning to his cool composure. He pushed back his hair, it had fallen out of place when he had been thrown against the tree. The air had grown cooler, he decided to head home.

Less than a mile away sat the Mystery Shack. Gideon had made it back with the book he found and was currently reading it under the blankets of his bed. Flashlight in one hand, the book open in the other. It was all incredibly fascinating to him, learning that Gravity Falls had so many secrets. It was intoxicating.

Tomorrow he would explore the town, he was probably going to stay far away from those woods for a while. His muscles would probably ache badly from all of his running, but it felt a bit adventurous in a morbid sort of way. He began to read a page about a sea monster until his eyelids grew heavy. He read a few more sentences before finally closing the book, clicking off the flashlight, and getting his so well-needed rest. He was still a bit shaken from his encounter from earlier, but not enough to keep him wide awake. He wondered who those two people might have been, and why on earth were they looking for that book?

But the question that disturbed Gideon Pines the most was:

How did they know that the book was there?