Hey guys. This idea I got from reading a certain fanfic about Gravity Falls + The Loud House, so why not have Gumball + Gravity Falls? This is set in a universe where the Watterson crew are human and Gumball keeps his name Zach, though Gumball will be used to address him occasionally. Enjoy!

[The episode starts with the Watterson kids next to the TV.]

Zach: Is there anything good on?

[Flicks channel. Nicole and Richard walk in with a cheesy grin.]

Nicole: Hi guys! We have... some news.

Darwin: What?

Richard: Well you see, summer is starting, and we don't really have enough money to take care of you.

Nicole: So we're sending you to live with your cousins, Mabel and Dipper in Gravity Falls!

[The kids' faces froze. Next place we see them is on a bus, with a sign saying "Welcome to Gravity Falls" outside the window.]

Gumball: We're finally here!

Anais [sarcastically]: Yay! [Flails arms.]

Darwin: Come on guys, it won't be that bad!

Bus driver: Next stop: The Mystery Shack!

[The doors opened to show a small shack and the Pines twins.]

Gumball: Hey. Who are you guys and where are we?

Dipper: I'm Dipper Pines, and this is my sister Mabel.

Mabel: And this is our house, the Mystery Shack!

Anais: Well, my name is Anais, these are my brothers, Zach and Darwin.

Gumball: But you can call me Gumball.

Dipper: Cool. Go with me bros. I'll take you to my room.

Mabel: As for you Anais, come with me! We're going to have fun!

Anais: I doubt it.

[They show the kids up in the bedroom.]

Mabel: I have an idea! To get to know each other better, let's play truth or dare!

Gumball: I'm down.

Dipper: That's a great idea.

Mabel: You Gumball, truth or dare?

Gumball [hesitantly]: Truth.

Mabel: Who is your current crush?

Gumball: Penny. She's the coolest girl in school. But enough about that, my turn!

Gumball: Dipper, truth or dare? [Grabs Dipper by the shoulders for dramatic effect.]

Dipper: Screw it. I pick dare.

Gumball: Oh, do you...

Darwin: You shouldn't have done that. Gumball picks the most embarrassing dares.

Gumball: Dipper, I dare you to eat Grunkle Stan's fez!

Dipper: I decline.

Gumball: Dang it.

Stan [downstairs]: Kids, go outside! Be children!

Dipper: Hey guys, I was thinking we let you in on a Pines family tradition.

Mabel: I'll get Grunkle Ford. He's our awkward sciencey uncle.

Gumball: So what are we doing?

Dipper: Mystery hunting! [Shows him the second journal.]

Dipper: This book has three parts, each exposing the weirdness in this town. Question is, are you with me?

[End of Act One.]