You're a savvy customer. But perhaps you'd be interested in buying... (Searching his pockets, then sees mushrooms and grabs him) This magic Mushroom! Sure, it doesn't look magic, but there's a very interesting story I'm about to make up about it.
Cut to Dipper in the attic.
Dipper
(Looking at box) The "What-the-heck-ahedron. Solve this puzzle and your photo could get on this box." (Turns the box around to show a picture of a boy holding up the puzzle and getting kissed by a girl in a swimsuit) Woah. That's false advertising I can get behind. (Takes puzzle out of box and turns it around. It beeps. He turns it some more) Come on... (It beeps again) Uh!
Mabel
Hey, Dipper! I got May May and the Dipp set up! Wanna record a few? (Presses sound effects board, making a honking sound three times and then a fart sound.)
Waddles
EEE!
Mabel
Woah! Not sure we can say THAT on the air! Don't touch that dial, truckers! Cause the Hogg just ate it.
Dipper
In a minute, Mabel. I'm trying to solve this intelligence puzzle but it seems impossible. (It beeps)
Mabel
Maybe you're just not smart enough.
Dipper
...We'll see about that. (Cut to him reading Journal 3:) "Buried near the falls is the legendary Percepshroom. To increase brainpower, grind it up and apply to forehead overnight" (Does as the instructions state; to What-the-heck-ahedron:) Tomorrow, I own you!
(The Percepshroom paste sinks eerily into Dipper's forehead.)
The next morning
Dipper
Ha-ha! I feel smarter already! The digits to pi are three point one four, one five nine, two six five, et cetera! Ha ha, yes!
Mabel
Dipper? Are you okay? You couldn't do that before.
Dipper
Yes, Mabel. And I know more than just the first 9 digits of pi. I know many things. I'm a new person. And I can teach you these things. I can teach you, Mabel. From the secrets of astrophysics, to the- (Notices Gompers chewing on his pillow) Hey! HEY!
Mabel
What happened to you? Have you been possessed by the spirit of a nerd!? Well, a nerdier nerd.
Dipper
No, nothing like that, I'm just going places.
Mabel
THIS ISN'T RIGHT! YOU'RE MY BROTHER! YOU GO WITH ME EVERYWHERE!
Dipper
Now I go wherever I can shine the light of knowledge into the darkness of ignorance.
Soos
(Walks in.) Hey, has anybody seen my- (Sees the What-the-heck-ahedron that Dipper solved) Woah! Dood! The What-the-heck-ahedron! How did you do that?
Dipper
I used a mathematical algorithm. It's fairly complex, though so…
Soos
Man, I am loving this new Dipper.
Mabel
Yeah! He's uh. He's definitely, uh, different.
Soos
Dood, that is amazing. You and me should go invent stuff!
Mabel
Uh, Dipper! Don't you want to stay up here and record some morning pranks with me?
Soos
Mabel, this dood's got a gift. He needs to share it with the world!
Dipper
I'm sorry, Mabel. There is more to life than making fart noises, and laughing at those fart noises. I see that now. (He and Soos leave)
Mabel
Right. Yeah. You guys. Just go on without me. (Presses fart button)
Cut to outside. Grenda's kite is stuck in a tree.
Grenda
Oh, my kite got stuck in a tree. I HATE EVERYTHING! (Sees Dipper, now wearing glasses and a labcoat and riding a Segway-type thing.)
Dipper
I bet we could be of service.
Grenda
Oh. Hey Dipper. Can you get my kite down?
Dipper
Ha! Forget kites! Here. Take this rocket pack I invented and explore the heavens yourself.
Grenda
Forget that! Grenda's gonna look at boys through skylights. (Flies away) I RULE THE SKIES!
Soos
Dood, that rocket pack we made is amazing.
Dipper
Don't forget the laser gun I made for Candy.
Candy
Death to my enemies!
Dipper and Soos
(Laughing)
Mabel
(On tape recording:) Welcome to May May and the Dipp. Top story today: coping with crippling loneliness after losing my co-host. (Presses button, which plays a recording of an electric guitar riff and a man saying "Loneliness!". Holds up a picture of "Dipper And Mabels 12th" What did that nasty goop do to you? You're not happier like this, are you?
Soos
(Fastening a bolt on a big machine) Dood, this is your greatest invention yet! It could solve every problem of mankind!
Mabel
(Coming in) What the heck is going on here?
Dipper
Mabel, you are just in time to behold our greatest achievement. The "Smarticle Accelerator".
Soos
Solving that brain puzzle was just the tip of the iceberg, Dood. With this, Dipper will be able to solve all the greatest puzzles of the UNIVERSE.
Dipper
(Drives into the machine) Gravity Falls, the origin of life, the meaning of existence, why dudes have nipples… I'm gonna save the world! (He presses a button, making the machine glow)
Soos
Soon, your brother is gonna be famous! Meeting with scientists, presidents, Everyone! He'll be World Famous!
Mabel
The whole world? But when will you have time for us? I'm your best friend.
Dipper
(He makes a mechanical hand pet her) I'm still your friend, Mabel, but I'm helping people now.
Mabel
But what about helping me? Do you really want to spend your whole life in meetings with dumb smart guys? This brain junk has made you forget who you are. Don't you remember... us?
(Dipper realizes, his sister is important to him. That he needs her. All that totally platonic, 100% nonromantic but still cute and fluffy stuff.)
Dipper
It all makes sense now. What good is helping the world if I can't help my favorite person in the world? It's a good thing I built in a dumb-dumb switch. (Pulls a lever from "FWD." to "REV")
Soos
Dood! don't! WAIT!
Dipper
I'm sorry, Soos. I want you to know that science is a horizon to search for, not a prize to hold in your hand. Also, I miss my sister. (Hugs Mabel, throwing off his science getup.)
Mabel
Thanks Dipper.
The Smarticle Accelerator falls down.
Soos
No! Our invention!
Dipper
Sorry Dude. But hey! We still got the What-the-Heck-ahedron
Soos
Oh yeah! Heh. Welcome back dood.
Cut back to Stan in the Mystery Shack.