Gumball, Darwin, and Mr. Small investigate the disappearance of Elmore Junior High student Molly (a gray sauropod character who was not seen on the show after season one) and soon find themselves sucked into a mysterious void containing all the mistakes the world has ever made.
- Anyone Remember Pogs?: Several of the objects found in the void are dated fads from the late 1970s to the 1990s, like pogo balls, laser discs, cassette tapes, jorts, the mullet, and disco.
- Brutal Honesty: Darwin and Gumball barely hesitate in telling Molly how boring they think she is. Mr. Small takes this a bit further and says if he was the universe, he'd probably regret making Molly and wish he could get rid of her (right before smashing his face).
- Borrowed Catch Phrase: Gumball, Mr. Small, then Darwin pull a collective "What?" "The?" "What?"
- Continuity Nod:
- The background seen throughout the void looks like the static that appeared when Gumball's and Darwin's voices changed at the end of "The Kids."
- Molly is found in her treehouse from "The Pressure" in the void, which, before this episode, was the largest role she'd had in any episode.
- Darwin and Gumball pass by Rob, the blue cyclops neither could remember in "The Pony", without even noticing him.
- Also floating in the void are the characters from How to Ratatwang Your Panda, the crappy Kung Fu Panda knock-off seen in "The Treasure".
- Cosmic Horror Story: A person vanishes from the world because the universe found him/her to be boring and erased all evidence of his/her existence? If this show didn't run on comedy, this would be a great premise for a horror or Sci-Fi show or film.
- The Cuckoolander Was Right: Mr. Small was right about people suddenly disappearing, even Janis—though it turns out to be a van, not his girlfriend. And when he said Janis runs on "good vibes" he's not even exaggerating: being nice to it makes it run better.
- Damned by Faint Praise: Darwin starts to admit the cheerleading team isn't as bad as he expected, because they didn't explode. But before he can even finish saying it...
- Eldritch Location: The titular void is some alternate dimension that houses everything erased from existence.
- Escalating Punchline: Darwin explains his lack of enthusiasm for the cheer team.Darwin: It's not that I'm not supportive but... they're kind of a train wreck... that like, a truck crashed into and... and then the whole thing sunk into a lake... and managed to catch fire... and exploded.
- Exit, Pursued by a Bear: A thinly-veiled parody of Crazy Frog is chased offscreen by two flightless birds—in this case, it's going the way of the dodo.
- Foreshadowing: While Gumball and Darwin are racing to save Molly, Rob can be seen in the background. This sets up the events of The Nobody, where Rob has escaped from the Void but is left disfigured and hit with Laser-Guided Amnesia as a result of grabbing onto Janice and being dragged against the opening as it closed.
- The Fourth Wall Will Not Protect You: When the void sucks up a person, it makes them difficult to remember and their absence unlikely to be questioned. The two previously-shown characters that ended up in the void are Molly and Rob, both of whom the audience would likely find hard to remember and not have questioned the absences of.
- Glad I Thought of It:Gumball: All we have to do now is build a tree house just like hers, and she'll come right to us!
Darwin: Or we can try and find hers since that's probably where she is.
Gumball: Or we could try and find hers 'cause that's probably where she is!
Darwin: Oh my gosh, that's a much better idea!
- Human Popsicle: Molly was missing for a whole year (even though no one has aged), but didn't notice any time passing or even that she left because she was frozen in place until Gumball and Darwin found her.
- Hypocritical Humor: Gumball loudly shames everyone for forgetting Molly, even though he continues to remember nothing about her but her name. He acknowledges this, but is unable to lower his voice, so he just walks away.
- Incredibly Lame Fun: Molly tries to argue that she's not boring by telling Gumball and Darwin about her pencil collection. They fall asleep.
- Leaning on the Fourth Wall: The way the universe will send things it considers "mistakes" to the void closely mirrors the way authors feel free to alter their world in whatever way they think will make the story better. Some of the stuff floating in the void includes actual design art that was rejected in the show's production.
- Left the Background Music On: As Gumball tries to remember Molly, the music and photos slowly passing by the screen turn out to be supplied by Darwin's humming and holding them in front of Gumball's face.
- Medium Blending: Someone interacts with the show's photographic backgrounds for the first time: Mr. Small, Darwin, and Gumball turn into CG so the perspective is able to shift angles, showing the backgrounds to actually be completely flat.
- Mythology Gag: The CGI version of Darwin used in the show's pilot is seen floating in the void.
- Not Hyperbole: Mr. Small says Janis could never go anywhere without him. It turns out she literally couldn't, as she's a van.
- Percussive Maintenance: Gumball beats on and yells at his own head to remember Molly. Everyone tries this on Janis (a van), but Darwin instead tries being nice to "her" and it worked.
- Plothole: After saving Molly and deciding to tell the world about the Void, the Void sucks up everyone's tinfoil hats, as they were what allowed them to remember the Void, meaning without them, they'd forget. Except Molly was never wearing a tinfoil hat, meaning even if they were sucked up, she should still remember. Despite this, she's shown with the same zoned out expression Gumball, Darwin, and Mr. Small are shown with.
- Pluto Is Expendable: Pluto is seen in the Void, implying that the world thought that Pluto was a mistake.
- Psychic Block Defense: The Tinfoil Hats Small and the boys wear to keep themselves from forgetting everything.
- Recoil Boost: Darwin and Gumball travel around in the void by propelling themselves with "highly toxic" hairspray from the '80s.
- Ret Gone: Things in Elmore deemed "bad ideas" by the universe are sucked into a Phantom Zone. Physical evidence of their existence is erased by removing them from photos and folding space over where their property was without anyone noticing the gaps this leave, and no one remembers them unless they're wearing a Tinfoil Hat.
- Stylistic Self-Parody:
- Take That!: Some of the things in the "terrible idea" dimension include Clippit/Clippy the Microsoft Office assistant and the Crazy Frog ringtone mascot.Gumball: (sees Crazy Frog)... Run him over.
- Victory-Guided Amnesia: Mr. Small, Darwin, and Gumball manage to escape the Void with Molly, but before they can tell anyone else their tinfoil hats are sucked into the portal, making them all forget everything.