The episode starts with Gideon inside his room, deciding on how to get revenge on the Pines family. He decides to gain control of the Mystery Shack. Gideon's lawyer appears at the front door of the Mystery Shack. Stan mistakes him for a tax collector and tries to hide his money somewhere else. The lawyer then says that Stan won ten million dollars and all he has to do is to sign a contract. The huge ten million dollar check rips apart and Gideon reveals himself. He says that he tricked them into selling the Mystery Shack, but instead of signing his real name, Stan writes "SUCK A LEMON LITTLE MAN'. Gideon swears revenge on the Pines.
Later, Dipper and Mabel play a game of chess, when Soos asks Mabel to reach a brain in a jar for him (He says, " The lady one," due to there being a wig on it). When Dipper asks why Soos chose Mabel over him, Soos replies because Mabel looks taller than Dipper. Soos measures them and Mabel is indeed revealed taller than Dipper by a one milimeter. Mabel and Stan start making fun of Dipper's height, and he storms off to his bedroom. Looking through 3, Dipper realizes that there are height-altering properties in the forest, and he goes to investigate. He comes across several crystals, ones casting blue and pink light. The pink light makes things smaller and the blue ones make things bigger. He takes a crystal and fastens the crystal to his flashlight and makes himself 1 millimeter bigger.
Mabel still believes she'll be taller in the end, so Dipper zaps himself again. Then Gideon arrives at the door of the Mystery Shack with cursed Egyptian termites, but Stan stops him from letting them devour it. After Mabel and Dipper fight for control of the magic flashlight, it falls into Gideon's hands, and he shrinks the two and puts them in a jar, which he takes back to his house.
In Gideon's roon, the villain places Mabel inside a bag of Gummy Koalas, where she eagerly takes a bite out of one. Gideon then interrogates Dipper about if he read about the crystal somewhere. Dipper then blows an air horn in Gideon's ear. He nearly squashes Dipper, but decides to use them. Soos and Stan finish setting up the Maze of Mirrors, a new attraction, when the phone rings. Stan goes to answer it, leaving his fez behind, which Soos wears. On the other end of the phone is Gideon, who claims that great harm will befall Dipper and Mabel if the deed to the Mystery Shack is not given to him. Stan refuses, and Gideon decides to go to the Shack, armed with the magic flashlight, and shrink Stan.
Dipper and Mabel escape using a hair brush, and ride a balloon to the Mystery Shack. Once there, Mabel distracts Gideon by messing up his hair with a gummy koala, and prepares to enlarge Dipper, however the duo argue about their height difference, and Gideon captures them. He then shrinks what he thinks is Stan; in reality it was just Soos wearing his fez.
After Soos inadvertently reveals Stan's location, Gideon sticks the jar containing the trio into his shirt pocket and heads to the Maze of Mirrors. Dipper asks Mabel why she was making fun of him, and reveals that Dipper beats Mabel at pretty much everything, and she wanted to win at something for once. They quickly make up and escape the pocket. The trio climb up Gideon's jacket and along his neck, but Soos is knocked off. Gideon decides to break the mirrors to find Stan, but he appears in front of Gideon, demanding that he pays $500 for each mirror he broke. Dipper gets an idea, and he and Mabel tunnel under Gideon's shirt to his armpit, tickling him so much he can't attack Stan, who simply rolls him out of the Mystery Shack. Mabel and Dipper return to normal size using the magic flashlight. Mabel stomps on the crystal to destroy it, but realizing Soos is still small, they decide to glue it back together to give him back to his regular height.
Gideon is pacing around his house, and his dad says he will get his revenge one day. Gideon angrily tells him that it's not just about revenge; he wants the Shack, the physical building, because there's a secret hidden inside of it. He then laughs maniacally while eating ice cream. In the credits scene, another person arrives at the door, telling Stan he's won $10 million. Stan simply closes the door in disgust, and the money is offered to Old Man McGucket, who eats the giant check.
- Viewership: This episode's premiere was watched by 2.60 million viewers.
- Gideon's school ID number is 618, a number that occurs frequently in the series, because it's Alex Hirsch's birthday 6-18-1985
- Mabel breaks the fourth wall by saying her favorite part is the theme song, and then the theme song came on. (This is only half true, she might have been talking about Duck-tective.)
- During the end credits, there was a cryptogram that read "GSV RMERHRYOV DRAZIW RH DZGXSRMT". Once decoded, it reads "THE INVISIBLE WIZARD IS WATCHING".
- The title of the episode refers to the constellation Ursa Minor. It's often referred to as the Little Dipper.
- The crystal that grows or shrinks things when a beam of light pass through it may be a reference to The Adventures of Teddy Ruxpin, where a similar crystal was a key tool for the heroes.
- Gummy Koalas are a spoof of Gummy Bear.
- Mabel turned on and held the flashlight similar to a Jedi pose in Star Wars.
- Mabel shouts into the closet "Expecto Wizardo!", a reference to the Harry Potter spell "Expecto Patronum!"
- Dipper says oh!, a reference to Regular Show. Coincidentally, Alex Hirsch, the creator, was friends with Regular Show's creator, J.G. Quintel, at Cal Arts.
- The "Maze of Mirrors" and the way Gideon smashes the mirrors is a reference to the Bruce Lee movie: Enter the Dragon.
- The Gummy Koala candy bag had a net weight of 5.29, but later, it reads that the net weight is 6.29.
- When Gideon grabs the contract, the front of it is faced towards Stan. In the next scene, the paper switches to the other side without Gideon moving his hand.
- When Grunkle Stan knocks the jar of termites out of Gideon's hands, it falls on the porch. When Gideon runs away, it is in the doorway.
- When Dipper and Mabel are playing chess, Dipper tells Mabel that black isn't her color. When Dipper checkmates Mabel he moves the white pawn to knock over Mabel's black king.
- Dipper grows the pawn while it is on the chess board, but later, it is shown in the background, out-of-place.
- When Dipper and Mabel are fighting over the flashlight, the caterpillar ran over a couple of cars but when Dipper and Mabel drop the flashlight the cars are gone.
- The Mystery Shack model is on the left side of Gideon's desk in the beginning. Later, Gideon closes his book and it is on the right side of his desk.
- The photo of Gideon on his ID card shows him with only four fingers per hand.
- When Mabel charges into her room, the closet door is open. But when she suspects a wizard made Dipper taller, she looks in the closet and has to open the door even though it was open and not tampered with when she arrived.
- When Dipper and Mabel tickle Gideon, the pine tree on Dipper's hat is missing.
- When Dipper shrunk, his hat shrunk with him. But when Soos shrunk, the fez hat doesn't shrink with him.
- When Mabel was in the bag Gideon put her in gummy koalas it showed Mabel without a headband. Later it came out in the bag.
- When Gideon was playing with the flashlight before he shrunk the twins, it's hard to notice but it was making the grow sound effect.
- When Gideon is running away from the termites, he leaves the jar they were in at the shack. However, when he shrunk Dipper and Mabel, he has the jar again.
- Dipper and Mabel are not visible in the jar when he turns to face his dad.
- During the flashlight duel, Mabel and Dipper do not flick the crystal, but the beams change.
- Written by:
- Tim McKeon
- Zach Paez
- Alex Hirsch
- Directed by:
- Aaron Springer
- Joe Pitt
- Storyboards by:
- Chris Sonnenburg
- Niki Yang
- With the Voice Talents of: