The episode begins at the Jötunheim residence, with Gumball and Darwin being assisted by Hector to build a diorama project of The Barrier Reef. He successfully inserts the paper octopus there, much to Gumball and Darwin's satisfactions. However, Hector accidentally blows the project far away, where it flew into and knocked out Goblin, who was taunting to a protesting Mr. Small that nature cannot fight back against him. Hector then complains to Gumball and Darwin that it is not great to be huge, for various inconvenient reasons. Gumball then comes up with the idea to use one of Mrs. Jötunheim's potions to shrink Hector, although Hector tells them that his mother will not allow it. Darwin, meanwhile, continually misunderstands Gumball's plans, much to his frustration. Mrs. Jötunheim then says to the two that she will not allow for a shrinking potion to be used on Hector, because he should learn to accept himself for who he is. Gumball tries to argue with her but realizes that there is no point in trying to argue, so he politely decides to leave the situation. When Gumball and Darwin exit, Gumball reveals that he stole Mrs. Jötunheim's potion book.
Gumball and Darwin make a shrinking potion in their house, and decide to test it on a bee, although they accidentally drop the sample potion and drop it on Larry's car, causing the car to shrink but not Larry, and Gumball and Darwin are eager about the results.
The two then persuade Hector to drink the potion, who is tempted by drinking it, although he reminds them that his mother will not approve of it. Eventually, Hector decides to drink the shrinking potion, and it immediately shrinks him down to around the size of the two without any dramatic shrinking effects. At first, Hector is extremely eager to be small, due to being able to use his full volume and being able to wander around freely. However, whenever he tries to enjoy everyday life, he either becomes exhausted or pushed around by others. Hector becomes depressed at being "like everyone else" to the point where he decides to sit on a swing, although he has to get off it to share the swing with other depressed people.
Hector then tells Gumball and Darwin to he wants to be to being a giant again, and he rudely says that he dislikes living with other people with his current size. As a result, he demands to the two that he return back to his giant size.
Back at home, Gumball and Darwin are making the potion that will turn an impatient Hector back to normal. Hector drinks the potion, but Gumball realizes that Darwin mistook "Orangutan toenails" for "0 rangutan toenails", meaning that he didn't put any orangutan toenails for the potion recipe. They notice that Hector develops mutated results (still the size of Gumball and Darwin) as a result, and the potion continually mutates Hector into weird features. Darwin tries to call Hector's mother for help, but Gumball tries to prevent Darwin from doing so, fearing that they will be in trouble in the process of doing so, while Hector continues to shape-shift. Gumball comes up the idea of sneaking through Hector's cave to obtain orangutan toenails.
Gumball and Darwin try to drag a now insane Hector near his cave, and they sneak through Mrs. Jötunheim to obtain orangutan toenails. When Hector starts shapeshifting again, he shrinks down and falls into a spider cobweb, and Gumball and Darwin become shocked by it approaching Hector. However, it turns out that the spider wanted a hug from Hector, and Gumball realizes that Mrs. Jötunheim is using orangutan toenails to brew her potion. Darwin accidentally lights up a tiny Hector from the magnifying glass, and although he then extinguishes the fire, he accidentally swallows Hector, who shape-shifts to a larger size, making Darwin choke. Gumball eventually eventually manages to stealthily obtain the jar of orangutan toenails, and he feeds it to Hector, who increases back to his usual giant size. Mrs. Jötunheim tells Gumball and Darwin to come over to see her drinks and a baked cake, which says, "I know what you did you boneheads." She reveals that Darwin did not hang up his phone the whole time when he called her. Gumball then questions her whether the drink she gave Gumball was actually a potion, and she reveals that it is a short term one that turns their hands into butts, ending the episode.
Hector previously dreamed of being the size of other people in "The Night," and his dream came true in this episode. However, Hector ends up becoming depressed as a result of being regular sized, due to various struggles as one.
Hector stating that he swallowed the last girl he kissed is a reference to "The Shippening," in which he tried to kiss Masami but instead swallowed her.
When Gumball said to Hector that when he becomes shrunken down, he can have his mother blame rap music for shrinking him, he references how rap music tends to start with "lil" in their artists' names.
The cloak that Gumball and Darwin used to become invisible is a reference to the Cloak of Invisibility from the Harry Potter series.
[In Hector's cave, Gumball, Darwin and Hector are making a model of a barrier reef. Gumball puts glue over a wooden fish]
Gumball: How can we not get an A with this? This diorama puts the "g" in biology. [He crouches with Darwin while they both wait for Hector to put a wooden octopus on the model] Come on. slowly, Hector. A bit more, a bit more. [Hector perfectly puts the octopus in the model] Perfect. [He and Darwin sigh]
[Hector sighs and the model and a dust storm falls on the model and leaves the faces of Gumball and Darwin stretched]
Gumball: Okay, let's try that again. [Sees that the model is gone] Where’d the barrier reef go?
[Outside the city hall, Mr. Small is holding a banner that says "Save the barrier reef"]
Mister Small: Protect the barrier reef, or one day, nature will strike back!
Goblin: Yeah, sure, hippie man! [sarcastically] Bring it on, barrier reef! I'll give you a free shot.
[The model of the barrier reef hits Goblin in the face. He straightens his tie respectably and faints. The scene cuts back to Hector's cave.]
Hector: Oh, sorry. I hate being so big.
Gumball: What are you talking about? It's great to be huge.
Hector: Trust in me, it's not. I have to stick my head in a car wash when I need to shampoo my hair, only to look like a poodle who chewed a power cord.
Gumball: Yeah, but at least girls like tall guys.
Hector: I swallowed the last girl I kissed. She broke up with me immediately. Well, a day later. [Gumball and Darwin look at him with an awkward face] Still, it’s a better feeling than being forced to use a volcano because there are no toilets your size! Which means the hair on your butt will never grow back because of the heat! And the people will laugh and point at it from every corner of the tri-state area!
[Gumball and Darwin look down with big puppy dog eyes]
Gumball: [gasps] I have an idea!
Darwin: Of course! Just do something to distract from your height! Like the Titanic was the biggest ship in the world, but all anyone remembers is that it's the fastest!
Gumball: Uh, I was thinking more about using one of Mrs. Jötunheim's book of potions.
Hector: No, Mom wouldn't let us.
Gumball: Aw, come on! All we need is a little potion.
Darwin: Of course! An intelligence potion to help us think of a solution!
Gumball: Darwin, if you're not gonna help, can you just walk away, please?
Darwin: Of course! The further away you get from Hector, the smaller he appears!
Gumball: I meant a shrinking potion!
Darwin: That makes no sense. If we shrink ourselves, Hector will only look bigger!
Gumball: Ugghh! [slumps and rolls his eyes]
Darwin: No, no, gimme a chance, I'll get there. [thinks for a moment] Is the potion itself shrinking?
Hector: I think the potion's for me.
Darwin: I think the potion's for me?
[Gumball heaves an exasperated sigh. Mrs. Jötunheim appears behind them.]
Mrs. Jötunheim: What potion are you talking about?
Darwin: [gasps in realization] A SHRINKING POTION FOR HECTOR!! [Gumball tries to shush him, but it's too late]
Mrs. Jötunheim: I won't allow it! [Gumball facepalms]
Gumball: But why? He doesn't like being a giant!
Mrs. Jötunheim: No potion will make you accept yourself for who you are. My son just needs to grow into himself.
Gumball: But I-I...[recomposes himself] I may not agree with your opinion, but as Hector is under your care, I shall not pursue this issue any further out of respect and deference to your authority. Good day, madam. [bows to her and walks out with his chest puffed]
[Cut to the outside of the cave. Darwin follows him out]
Darwin: You stole the potion book, didn't you?
Gumball: [takes the book out from behind his back] Yup!
Putting Together the Potion
[In Gumball and Darwin's bedroom, Gumball stirs a glowing blue potion inside a cauldron.]
Gumball: Okay, the next ingredient is...[checks book] a fragment of a broken dream.
Darwin: Man, it was hard enough milking all those wolves!
Gumball: We only had to milk one!
Darwin: But the others looked so left out! Now, how are we gonna get a fragment of a broken dream?
Gumball: Dad's Elmore Gym membership card! [holds up the card]
Darwin: [shrugs] Hm. Yeah.
Gumball: Very good. [drops in the card, which turns the potion green] Now for the last ingredient: a head of rosemary flower.
Darwin: Wait, did you just say a head of rosemary flower...or the head of Rosemary Flowers?
Gumball: A head of rosemary flower.
Darwin: Probably should've asked before I started digging. [picks up a sack, drags it offscreen, and comes back holding a sprig of rosemary] That was a lot easier. [He puts the rosemary inside, and a green mushroom cloud erupts from the potion.] What now?
Gumball: We should try it on something to make sure it works.
[They look out the window, Gumball holding a pipette full of the potion. Darwin points to a bee on the roof]
Darwin: There! Aim for that bee!
[Gumball lowers the pipette to the bee, but it flies away at the very last second. Gumball screams and throws the pipette out the window. It bounces off the roof, and lands on Larry's car, shrinking it promptly while his arms and legs break out the windows.]
Larry: Huh? What?! AAAAHHHH!!!
[Larry's tiny car swerves out of control and hits the side of Siciliana's. Panicking, he starts crawling around on all fours, still inside his car. The boys, taking in this whole scene, gasp in shock.]
Gumball and Darwin: AAHHH!! [smile at each other] It works!!
Hector's Tiny Adventures
[In the Elmore Junior High courtyard. Gumball and Darwin hold up a vial of the potion to Hector.]
Gumball: C'mon, man! Drink it! We used all the best ingredients. Swine gums, withered monkey hands, frogspawn...
Hector: Sounds tasty, but isn't it dangerous?
Gumball: Okay, side effects might include total annihilation, a fate worse than total annihilation, and a fate worse than a fate worse than total annihilation. But--what if you actually survive it?
Hector: You make it sound so tempting! But what about what my mom said about growing into myself and stuff?
Gumball: You would still be growing, but into a.....smaller self. You'd be obeying her technically, but not....actually?
Hector: I don't know if my mom will buy that.
Gumball: Then just do what everyone else does and blame it on rap music.
Hector: What's rap music got to do with a shrinking potion?
Gumball: I dunno, they're all called "Lil" something.
Hector: Okay, I'm in.
[He takes the potion and drinks it. Suddenly, the sky goes gray and cloudy, the wind blows, and dramatic music plays. Gumball and Darwin slowly gasp. Cut to reality: Hector shrinks in a snap with a toot sound.]
Gumball: I kinda expected something a little more...dignified.
Hector: [whispers] Uh—[Does hand gestures without talking]
Gumball: What was that now?
Hector: [in a higher pitched voice] I'm sorry, I'm not usually allowed to use my voice at full volume. Now I'm normal! I can do ANYTHING!! [Skips off ecstatically]
[Fade to Hector running in a field]
Hector: I can run! [slows down] But not very far because I've never had to take more than two steps to get anywhere.
[Hector rides a bike through the city]
Hector: I can cycle! Wait, no I can't. I NEVER LEARNED!!! [Veers out of control and gets knocked out by the underside of a "For Sale" sign]
[At the stadium, Hector plays football]
Hector: I can play football!! [All the other players tackle him, and two paramedics carry him out on a stretcher] I can fit on a stretcher!
[At the mall, Hector skips up to Debbie, Rotten Cupcake, and Clare]
Hector: I CAN KISS GIRLS!!! [He jumps at Debbie, and screen cuts to black as punching noises are heard] I can get knocked out by girls. [Julius, Scythe, and Jared all lunge at Hector and beat him up.] And their boyfriends!!
[On the sidewalk, Hector runs up to Principal Brown and grabs him by the shoulders]
Hector: I can see what people look like up close!
[He stares at Principal Brown, but realizes his face close up is disgusting. He stares at Jeff and Tony, but they aren't any more appealing up close]
Hector: [cheerfully] And I don't like it!!
[He skips up to a public bus]
Hector: I can finally use public transport! [On the bus, his face is jammed in the Melted Cheese Guy's armpit] I CAN TASTE PEOPLE'S SMELL!!!
[In the school hallway, Hector is in front of his open locker]
Hector: I can be like everyone else!! [Julius runs up, shoves Hector into his locker, and closes the door]
Julius: And I can make up for not being able to do this for five years! [Opens the locker, takes Hector out, shoves him back in, and closes it again]
Hector: [While Julius repeatedly takes him in and out of his locker] I can be like everyone else! I can be like everyone else!
[While the sun sets, Hector is sitting on the swing at the park, depressed]
Hector: [sighs] I'm just like everyone else.
8-Bit Dog: [off-screen] Uh, sorry? [There's a line of people waiting to use the swing] It's, uh, my turn to be depressed. [Hector sighs and gets off] Thanks.
Back to Abnormal
[The next day, back in the Elmore Junior High courtyard. Hector approaches Gumball and Darwin, who are eating lunch.]
Hector: I wanna get back to normal.
Gumball: You mean back to abnormal?
Darwin: But why?
Hector: Yeah, I don't wanna be insulting, but living down amongst people is like living amongst gross, selfish, bacteria-riddled cockroaches.
Darwin: [sarcastically] Wow. Glad you weren't trying to be insulting.
Hector: Sorry. I apologize.
Darwin: [smiles] Thank you.
Hector: To cockroaches. [Gumball and Darwin sigh]
Gumball: Okay, so you want us to make a growing potion?
Gumball: And, what's the magic word?
Gumball: No, dude, the magic word is-
[Back in Gumball and Darwin's bedroom. Gumball and Darwin mix up a new potion in the cauldron while Hector watches impatiently.]
Gumball: OKAY, OKAY!! We heard you the first hundred and twenty-three times!! [Dips a cup into the potion and hands it to Hector] Here. [He drinks it, but nothing happens] Mm. Nothing. S'kinda weird. [to Darwin] Uh, you must've missed something.
Darwin: No. I followed every instruction!
Gumball: [Glances at the book] What about this?
Darwin: [Points to the words "Orangutan Toenails" in the book, but the O is spaced out a little farther form the rest of the letters] Rangutan toenails! It says zero, so I didn't put any in. Not one of 'em.
Gumball: "Rangutan"? What on earth is that?
Darwin: I don't know, but it's definitely not in it!
Gumball: [Grabs the book and looks at it] It says orangutan toenails, man! As in the ape!
Darwin: I think you'll find they're called "orange utans".
Gumball: W-wait-wait-wait. You think that type of ape is called "utan", and is referred to as orange because of the color of its fur?
Darwin: Yeah, 'cause they're ginger, innit?
[Gumball and Darwin crack up laughing. Gumball wipes a tear.]
Gumball: [To Hector] Aw man, did you hear that? [They look at Hector, whose nose and mouth have grown, but not the rest of him.] Ohh! Dahhh! He looks like the blobfish from the internet kissed the drain at the bottom of the pool! [His entire head inflates] Daaahhh!!! He looks like a one-man parade float!! [He is squished into a melting blob] DAAAAHHHH!! He looks like a carpet made out of Great-Grandpa's tummy tucks!!!
Hector: Guys? [hiccups a cloud of the potion] I'm feeling a pittle leculiar.
Gumball: Oh, man! It's 'cause we missed that ingredient!
Darwin: Uh—okay! [takes out his phone and calls Mrs. Jötunheim] I'll call his mom! She'll know what to do!
Gumball: What? No! She'll punish us by giving us butts instead of hands or something! We'll never be able to wear gloves again!!! [Hector's butt expands and he collapses under the weight.]
Darwin: I don't think that'll be our first problem, but I get your point.
Gumball: Okay, then. Let's get to Mrs. Jötunheim's cave. We need to get those orangutan toenails.
Darwin: But you said she'd be mad if she sees us!
Gumball: Ah, but she won't see us! [whispers] We'll be stealthy.
Darwin: [whispers] Like Trojan dorks.
Gumball: Dude, it's not what—ah, whatever.
Mission in the Cave
[Outside the Jötunheims' cave, Gumball and Darwin balance a woozy Hector, who is walking aimlessly. He falls on his face, and laughs.]
Darwin: Dude, are you feeling okay?
Hector: [Unsticks his face from the ground] Yup! I'm feeling HECTOR!! [Leans forward and giggles]
Gumball: [Holds up two fingers] How many fingers am I holding up?
Gumball: Okay, murple's not a number.
Darwin: And it's not a color either.
Hector: Heh heh heh!!
[Gumball shushes Hector, who playfully shushes him back. As he does, his hand grows abnormally big and crushes Gumball. The sound echoes through the town.]
Hector: Hehehehe!! [gasps] I can hear footprints!
Darwin: Ahh! His mom's coming!! [He tries to pull on Hector's hand, which doesn't budge. Suddenly, he shrinks to near invisibility, and Gumball and Darwin hide behind a rock just as Mrs. Jötunheim walks out. She looks around, sees nothing, shrugs, and goes back in.]
Gumball: [Looking at the grass] Dude! Where are you? [Hector's head expands, hitting Gumball in the chin] There it is.
[Hector shoots up in height, flinging Gumball in the air]
Darwin: HECTOR! CATCH HIM!!
Hector: I sot gis! [Holds out his arms, but right as Gumball is about to be caught, his arms shrink and Gumball hits the ground] I don't sot gis.
Gumball: Look, just no more goofing around, okay? [Hector gives him a thumbs up. His thumbs grow long enough to go into his nostrils.]
[Inside the cave. Mrs. Jötunheim is working on a potion, while Gumball and Darwin sneak in. They motion for Hector to come over, and he stumbles over giggling. Darwin checks a shelf.]
Darwin: Dude! Where are your mom's toenails?
Hector: On her toes, I guess! [Stifles a laugh]
[Gumball shushes them both, grabs a cloak of invisibility from a coat hanger, and covers them. Mrs. Jötunheim turns around, sees nothing, and goes back to work.]
[They remove the cloak. Darwin bounces on top of Hector, but as he is about to jump, Hector shrinks. Darwin hits the ground, and Hector lands on a spiderweb. ]
Gumball: Where is he?!
Darwin: He shrunk again!
Gumball: [Hands him a magnifying glass] FIND HIM!
[A spider crawls onto the spiderweb, approaching Hector. He stifles a scream.]
Darwin: I got him! [Holds the magnifying glass on Hector, who is now cuddling with the spider]
Gumball: Good! Just keep an eye on him while I find the jar of—oh, boy. [He realizes Mrs. Jötunheim has the toenails] They're on her table!
Darwin: Go for it! I'll keep an eye on Hector!
[He unknowingly moves the magnifying glass into the light, burning Hector and the spider. Hector screams. Darwin panics and blows on the flame, but it doesn't go out. Meanwhile, Gumball, wearing the cloak, slinks up to the table and reaches his hand out, but accidentally touches a frog. Mrs. Jötunheim notices this, takes a sip of her coffee, and sets the mug down on Gumball's hand. Darwin spits on Hector, which finally puts out the fire, but now he is drowning in the bead of spit. Darwin gasps, inhaling Hector, and chokes. Suddenly, his leg expands and comes out of Darwin's mouth. Seeing this, Gumball panics and throws Mrs. Jötunheim's coffee mug into her cauldron, distracting her long enough for him to take the toenails and put them in Hector's mouth, and he finally grows back to size.]
Mrs. Jötunheim: [Rubs her eyes] Agh! [turns around] Ah, boys! Come over here. I just finished baking a cake!
Gumball: [Grinning awkwardly] Oh, you shouldn't have!
Mrs. Jötunheim: Oh, don't be silly. [Hands them mugs of steaming pink liquid] Now, here are your drinks...[takes a cake out of the oven] and here is your cake.
Gumball and Darwin: Ah! [Look at the cake] Huh?
[The cake is revealed to say, "I KNOW WHAT YOU DID YOU BONEHEADS" in icing]
Gumball: "I know what you did, you...boneheads". [She grumbles at them] How?
Mrs. Jötunheim: [Holds out her phone] You forgot to hang up when you called me earlier.
[Darwin hangs up with a guilty look on his face. Gumball looks at his mug.]
Gumball: Ugh. This is a potion, isn't it?
Mrs. Jötunheim: Just a short-term one. I like that idea you had, the hand-butt swap potion.
Gumball and Darwin: Hmm? [They pull out their hands, and sure enough, there are butts in their place. One of Gumball's butt-hands farts, and the episode ends.]