The boys and Julius breaking out of school.
Principal Brown: I'm putting you in the long detention block. So from now on you don't eat, you don't go to the bathroom, you don't speak, you don't even blink unless I say so. DO YOU UNDERSTAND?
Darwin: Can I blink?
Principal Brown: No.
Darwin: Can I blink?
Principal Brown: No.
Gumball and Darwin get school detention for a week for cheating, which is treated like a maximum security prison, and meet the unruly detention kids. Not being able to take it, they join forces with Julius, an aggressive black-and-white 1920s cartoon character with a bomb for a head, to break out.
Tropes:
- Air-Vent Passageway: Julius’ plan to get out of detention was to climb through the air vent to the roof. Problem is he has no way to open the roof vent from the inside, which Gumball gets around by tricking him into blowing himself up and the vent with it.
- An Aesop:
- Do not cheat.
- If you can't do the time, don't do the crime.
- Never get caught.
- Bathroom Control: Principal Brown lists off a number of things that Gumball and Darwin may not do during their stay in detention while walking them to the room. One of them is going to the bathroom.
- Cheaters Never Prosper: The whole reason Gumball and Darwin end up being in detention for spring break.
- Cool and Unusual Punishment: For taking things out of Principal Brown's desk (and laughing at the risque pin-up calendar he made for Miss Simian), Gumball and Darwin are forced to listen to Mr. Small's extremely long, boring poetry about being a shoe.
- Chekhov's Lecture: Darwin and Gumball start the episode reviewing the Pythagorean theorem, and at episode's end need it to figure out the length of rope necessary to make a zipline off the school's roof. They don't remember any of it and Darwin points out that if they knew that much math they never would have tried to cheat and get put in detention in the first place. The two of them instead just jump right off and ignore the injuries.
- A Day in the Limelight: For Julius.
- Detention Episode: Gumball and Darwin are sent to detention, which is portrayed like a maximum security prison.
- Did I Just Say That Out Loud?: The first moment Darwin and Gumball spend in detention they insult everyone while thinking they were psychically talking to each other. They weren't.
- Does This Remind You of Anything?: The sequence in the spring break detention is modeled after a maximum-security prison, complete with smuggling contraband in (and using the restroom to defecate it out, as seen with Gumball and the rake), the break-out plan, Gumball and Darwin getting tattoos to look tough, the "detention slang," the cupcake getting his "cherry" broken during the riot, and Principal Brown acting like the hard-assed warden who doesn't care about the inmates.
- Downer Ending: Gumball and Darwin escape detention. But as Principal Brown points out, they still have to come back tomorrow.
- Double-Meaning Title: "The Lesson" either refers to the actual lesson that Gumball and Darwin neglected to study for or the lesson they learned about cheating in the end.
- Had to Come to Prison to Be a Crook: Gumball and Darwin have to break more rules to bribe the other students into not beating them up. By the end, the two double cross one of the other inmates to escape ("Well played." "I learned from the best.") and Gumball says the lesson he learned was "never get caught".
- Human Notepad: Gumball and Darwin try to cheat with crib note written on their bodies, but are instantly foiled by their short-sighted choice of location:Principal Brown: Did you really think you could get away with this?
(camera switches to Gumball and Darwin, the latter's body entirely covered with mathematical gibberish)
Gumball: To be honest? Yeah, I thought we could. I have no idea what went wrong. - Hurricane of Euphemisms: Darwin expresses the idea of cheating on the math test to Gumball with a series of strange clicks and whistles which take him a while to get.
- Match Cut: After Darwin and Gumball realize they just accidentally insulted a bunch of the tough kids, the scene cuts to later in a different location. Both are located on the same part of the screen, except they've both been horribly beaten.
- Jerkass Ball: Staying in extended detention probably wouldn't be so terrible if Principal Brown wasn't treating students like hardened criminals and making almost no effort to keep them from beating the crap out of each other.
- Person of Holding: Darwin pops off his leg and stores silverware inside. In the next scene Gumball swallows a rake whole, then is implied to have passed it out the other end.
- Saying Sound Effects Out Loud: Since the school doesn't have a siren, Principal Brown just makes the sound of one into the loudspeaker during the detention break.
- Stealth Pun: In a detention portrayed like a prison all episode, Mowdown attacks a living cupcake by tearing off the cherry on top and crushing it between his jaws. Gumball reacted to seeing it with the line "Did you see what that bear did to that guy's cherry?" He popped his cherry. After seeing that, he and Darwin are especially sure they need to break out.
- "Shaggy Dog" Story: Gumball and Darwin pull off a Great Escape from detention, but as they're limping off Principal Brown points out they're "escaping" from school, so their parents will just make them come back the next day.
- Sophisticated as Hell: Gumball eats the pages of an Elizabethan poetry and his slang (such as "What the what?" and "Chill out, dude") becomes refined ("By my by?" and "Be still you cur!").
- Take That!: The detention class parodies the United States prison system and the effect it has on inmates.
