Ghostly Mysteries (Danny Phantom/Gravity Falls crossover)

Chapter 1

The sun shines down upon the forest of a small town, the birds sing happily and peaceful silence ruffles through the air. Soft footsteps of creatures known and unknown press through the grass and undergrowth, happily hidden away from curious eyes.

A loud groan interrupts the peace of the forest, followed by stomping feet as a set of twins push their way through the shrubbery.

"Blenngggghhhh... Dipper! How much longer do we have to stay out here? It's hot!" The girl, Mable, complained to her brother, her pink dolphin sweater drenched in sweat.

Her brother, known as Dipper, didn't even look up from the journal he was holding, "Well, maybe if you didn't wear three-inch thick sweaters everyday in the middle of summer, you wouldn't be so hot."

Mable glared at the back of his head, "They're not three inches! They're 2.67, thank you very much. Besides, these are my summer edition sweaters! My sumweaters, if you will."

"Your sumweaters are going to give you heat stroke."

"Well, if you keep that attitude up it might just happen!"

"It won't be a karma thing, Mabel," Dipper retorts, finally looking from the journal to his sister, "Besides, I know theres something out here. I saw it!"

Mabel rolls her eyes, "I'm not sayin' you didn't see anything, but we see something everyday! It's probably just gnomes or somethin'." Nevertheless, she takes off her sweater and ties it around her waist, knowing they're not going to be leaving the heat anytime soon.

Dipper turns back to his journal and ducks under a fallen tree, "Yeah but... I know this is different. I can feel it." He flips slowly through the old pages of the book as Mable opts to go over the log instead of following her brother's steps of going underneath.

Dipper heads deeper into the forest, pushing away more branches and leaves as he does so. He's so focused on his journal that he fails to process Mable's sharp gasp and small tap. It's only when she starts furiously poking his arm that he looks up and glares.

"Wha-?!" His mouth is covered and he notices the look on his sisters face, expression softening and following the line her finger made towards a lump of... something next to a tree. Mable removes her hand as the twins slowly approach.

The closer they get, the more they can see. A head of black hair, blue jeans, a white t-shirt, pale skin... but something isn't right. Dipper strains his eyes until the figure shifts, visibly contorting in pain even as it seems asleep. That's when Dipper and Mable get a proper look at him.

The figure is a human boy, probably a teenager, and he was covered in blood.
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Needless to say, Danny Fenton was absolutely not having a good week so far.

Sure, it started fine; school was out and he was spending time with his friends at the mall before, naturally, his ghost sense went off. It turned out to just be the box ghost, so he told his friends to keep going, that he's going to be fine, that they should have fun and he'll join them in a bit.

That was two days ago.

Now, he was helping his giant, on-the-run-from-the-ghost-police dog friend, Wulf, with being on the run from the ghost police. Wulf had met up with him after he had trapped the box ghost in his "cruel cylindrical container", explaining (rather slowly so Danny could understand) that Walker had found them. Of course, what Wulf had failed to explain was that Walker and his endless army of guards were two minutes behind Wulf, and had appeared through the last portal that he had opened.

Without the time to tell his friends, Danny climbed onto Wulf's back as he sliced a new portal to the Ghost Zone into existence. They leaped through, followed by the Warden and a handful of the guards. They'd been jumping in and out of portals to get away, but around the seventh one, a guard had gotten lucky and thrown a spear, which had landed its mark.