It's been days since Dipper and Mabel went back into civilization. In other words, back in the city. Days ever since their summer vacation at Gravity Falls ended. They're back in their normal, yet boring life without supernatural adventures. Then again, Oakland wasn't the center of such thing.
At least it's four days before Halloween and it's their chance to find something exciting. Perhaps a mystery would be good, just like in Gravity Falls. A day ago, they got it when they received a package with the instruction, 'Do not open until a mysterious voice is heard'. They could only hope that the voice they'll be hearing is a good one.
A second later, they heard the doorbell ring. Dipper opened the door, and he found nothing outside their suburban home. Well, aside from the Halloween decorations found by the other houses. He closed the door afterwards.
"Who was it, Dipper?" Mabel asked.
"No one. No one was answering the door," Dipper replied.
"It could be a ghost. After all, some of them have powers of invisibility."
"Sure Mabel, let's go with that. If it were a ghost, then a boo would certainly be heard right about now."
"Boo!"
"Aah!" Dipper yelped. "It's a ghost!"
"Ha ha, gotcha, dude. And I see you're still wearing the hat that I gave you on the day you left Gravity Falls."
"Wait, Wendy?" Mabel recognized the voice speaking to them right now. "Are you really here right now?"
"Yeah, I'm here right now," Wendy replied unseen, and Mabel felt her touch as reassurance. A second later, she and Dipper felt her arms wrapping them for a hug, and they returned it. They're just happy that a friend from Gravity Falls came for a visit.
"What happened to you? Why are you invisible?" Mabel asked.
"I'll be happy to answer your questions, Mabel. First things first, do you have the package that I sent you?" Wendy said.
"You mean this one?" Dipper asked, revealing the package that was sent to their home the day before.
"Yup, that's the one. Now that you heard the mysterious voice, you should open it."
The twins opened the package that was sent by the unseen redhead, and they found familiar stuff in it.
"You sent your ax and clothes here? Why did you do that?" Dipper asked.
"Can't you take a guess?" Wendy asked rhetorically with blush marks appearing on her unseen face.
A second later, the twins realized what this means.
"Aah, shield your eyes!" Mabel exclaimed as she attempted to cover her brother's eyes.
"Stop that, Mabel! It's not like I can see her na..." Dipper yelled in the struggle.
"Right, I gotta dress up first," Wendy said.
Author's Note: What do you think of Wendy becoming invisible? It surely represents the fact that unlike everyone in the show, she didn't have an episode about herself. She's the only one who's not being explored more. Good thing Alex Hirsch regretted that. If she were to have her own episode, this is what I had in mind.
