I do not own Gravity Falls.
Mabel quietly sat in her bed, staring at the other side of the room, her eyebrows furrowed, as she looked at her brother in worry. Despite being asleep, he still was moving, nearly frantically, rustling the sheets beneath him with every turn. His teeth were clenched in what seemed to be a rather painful manner, his hands tightly fisted, and his eyes shut to the point of practically distorting the rest of his face. Even in the darkness, Mabel could see the sheen of sweat coating her brother's forehead, and his fearful mumbling could be heard throughout the room.
It was just as Mabel feared; her brother was in the same condition he had been in for the past week come sundown. He was once again haunted with what seemed like absolutely wretched nightmares.
Of course he would never talk about them. Dipper was far too proud for that, but she still managed to see the signs. During the day, he was even jumpier than usual, and the bags under his eyes grew deeper with each passing night.
Plus, he kept waking her up in the middle of the night from a combination of muttering, rustling, and the occasional desperate scream ripped from his throat as he awoke.
She was pretty certain he never noticed her watching from under the her blankets.
If he did, he would probably already know how insanely worried she was about him.
Mabel knew that nightmares were a common issue, and one that didn't necessarily have a way to fix it, but she'd be darned if she wasn't going to try. These dreams were bothering Dipper nightly, and no one messed with her brother if she had a say in it.
Of course, it would be a lot easier as a joint operation...
"Grunkle Stan?" Mabel called out hesitantly as she came down the staircase, already having checked to make sure that Dipper was not in the house.
"Yeah kid?" he responded from, as she expected, his spot in front of the TV.
"I want to talk to you about something," she started slowly, hopping onto on the arm rests and pulling on her sweater.
"What?" he asked, his voice clearly nervous as he realized this was probably something of importance.
"I'm... well, I'm kinda worried about Dipper," she said as she lifted her head to meet eyes with her great uncle.
"... Why? What's wrong with your brother?" Stan's voice was full of both confusion and honest concern, though the latter was more concealed.
"He's been having nightmares every night for the past week. At first I thought it was nothing, but I really think it is getting to him," Mabel widened her eyes with every word, practically pleading for help.
Which was something Stan could not say no to.
"Well... What causes nightmares? If we can get to the cause, maybe there's a solution?" he eventually replied, uncertainty in each syllable.
However, Mabel lit up as he finish, jumping from the chair.
"That's it, Grunkle Stan! To the library!"
"What? Wait-" Stan started to protest, but was he was already being dragged out of the chair and through the doorway by a quickly talking Mabel.
"There's sure to be books about how nightmares are caused there! Research may be more Dipper's thing, but he's never gonna agree to do that for himself, so it is up to us, Grunkle Stan!"
After a moment, he decided to not fight it, since it was worth the boring time in the library to see Mable so animated. With a small smile, he let himself be led out of the shack door.