Homer (like practically every Springfielder who isn't a Flanders) waits until the last minute to file his tax return, and the IRS has jailtime in store for Homer — unless Homer plays spy to retrieve a trillion-dollar bill that Mr. Burns was supposed to deliver to post-World War II Europe to pay for reconstruction and stimulate the economy.
- Abusive Advertising: The Duff ad in Cuba with Che Guevara has the slogan "El Duff-o o muerte (or death)". Considering that it's on a communist nation that executes prisoners...
- All of Them: The reasons for visiting Cuba are: business/pleasure; smuggle cigars; assassinate Castro. Homer checks all of them.
- Bad Liar: Want an idea of how poorly Homer did his taxes?Homer: Okay, Marge, if anyone asks, you require 24-hour nursing care, Lisa's a clergyman, Maggie is seven people, and Bart was wounded in Vietnam!Bart: Cool!
- Boxed Crook: Homer agrees to work as an IRS snitch to avoid going to jail.
- Call-Back: When Kent Brockman asks Krusty the Clown why he waited till the last minute to file his taxes, he says "Because I'm an idiot. Happy?" Evidently, he hasn't gotten over his brush with the IRS in "Bart the Fink".
- As Lenny writes his tax forms on Professor Frink's back, Frink takes note that he didn't carry the one, a mistake he himself made in "Itchy and Scratchy Land" when he failed to predict when the park robots would run amok.
- Captain Crash: Really bad cataracts, lack of practice and a lot of senility makes Burns crash, rather than land, the plane in Cuba. Smithers and Homer actually share a This Is Gonna Suck moment when they figure this out one scene beforehand.
- Crazy-Prepared: Ned always files his tax returns every New Years.
- Chekhov's Gun: The plane Burns is seen using to "take" the dollar bill to France turns out to still be in his possession on the third act, and it's used to go to Cuba.
- The Dead Rise to Advertise: A billboard of Che Guevera is seen advertising Duff Beer.
- Disco Dan: Mr. Burns' out-of-touch-with-the-times tendencies are in full display here. He thinks Homer is a reporter for Collier's, which had ceased publication in 1957 (although it was briefly revived in 2012), and while in Cuba, was shocked to learn that Batista was no longer in charge. He also identifies a taxi as "the new Packard they've been talking about."
- Does This Make Me Look Fat?: Homer asks this about the wire he has to wear under his shirt.Lisa: No, it makes you look like a tool of government oppression.
Homer: But not fat.
- Dude, Where's My Respect?: Smithers is upset when Mr. Burns doesn't appreciate the dinner he prepared, saying "Sometimes, I don't know why I bother..."
- Eagle Land: Burns believes that performing such a blatantly treasonous crime as stealing the trillion-dollar bill (and going against orders given to him by the government) is a showcase of his patriotism (as he puts it, he's just keeping the money away from a country that doesn't deserves a hand-me-down that would make America poorer). He later says that bribing a jury in order to prevent being put in jail for said crime is also "the American way" and Homer even salutes him and says "God bless America!"
- El Spanish "-o": The Duff Beer ad that we see in Cuba calls the brand "El Duff-O".
- Exact Words: Doubles with Police are Useless. When Homer, Smithers and Burns escape from Burns' mansion, Chief Wiggum receives a radio message to look out for Burns' maroon-coloured ancient car. When it drives by, Wiggum notes the car is more of a burgundy and does nothing.
- French Jerk: Apparently, this trait started because Burns stole the trillion dollar bill meant for Europe.
- Historical In-Joke: Mr. Burns has the suit Charlie Chaplin was buried in, which suggests that Burns was the one who stole Chaplin's coffin in 1978, a few months after Chaplin's death and funeral.
- Horrible Judge of Character:
- Everyone who expected Mr. Burns to be the most reliable person to deliver the trillion-dollar-bill just because he's America's richest person.
- Mr. Burns simply gives the dollar bill to Fidel Castro, who is an extremely corrupt man. When Mr. Burns asks him to give it back, the president just asks what, taking the money away and putting Mr. Burns, Smithers, and Homer on a meager rack in the middle of the ocean.
- Insane Troll Logic:
Homer: Shut up, shut up! If I don't hear you, it's not illegal!
- After Marge points out how Homer is lying on his taxes (as he rushes to complete them last minute), he immediately covers his ears.
- One scene later as he's driving like a madman to get to the post office in time, he sees that an upcoming crossroads has a red light and he covers his eyes, saying that if he doesn't sees it, it's not illegal. He causes a pile-up as a result.
- Intimidating Revenue Service: Homer is forced by the IRS to become a spy for them or face criminal charges for his badly-made tax forms (ironically he may have prevented this by just not bundling all of the forms together into the shape of a football).
- Irony: Burns was chosen to deliver the dollar bill because he was one of the most trusted men in America to do the job. Not only does he not do that, believing it's his patriotic duty to perform said theft, but other episodes (Negative Continuity aside) have mentioned that he was a Nazi collaborator.
- Mixed Metaphor: While reporting the midnight rush for mailing taxes, Kent Brockman says "It's literally the eleventh hour: 10 PM!".
- Oh, Crap!/This Is Gonna Suck: The look on Homer and Smithers' faces after they remind Mr. Burns that he's flying the plane... and he's about to attempt a landing.
- Out-of-Character Moment: When the family is being asked by government agents what would Homer do with the Zillion-Dollar Bill he's been accused of stealing, Marge says that the money should go to the kids' college fund... only for Lisa to reply "Who needs college? Let's buy dune buggies!" Huh? This coming from the girl who, after helping put Mr. Burns back on his feet, refused her rightful million dollar advisor fee out of moral disapprobation for how he did it.
- The Password Is Always "Swordfish": The codeword to activate the secret film strip about the trillion dollar bill in the mall's photo booth is "cheese". Apu inadvertently activates it right after Homer and the IRS agent leave.
- Ridiculous Procrastinator: Inverted. Ned Flanders begins preparing his taxes after midnight on New Year's Day (he even acts like he's incredibly late when in actuality he's the very first person to get to the post office for the day). Played straight with just about everyone else in Springfield, who only start filing their taxes at the last minute, and the reason Homer's whole dilemma occurs is because he was the one who waited the most out of the whole city (rushingly bundling all of his badly-filled forms into a bundle shaped like a football (which made it roll into the audit bin at the IRS) and actually having to toss it into the outgoing mail pile through the closing office's doors).
- Screw the Rules, I Have Money!: How Mr. Burns intends to avoid punishment.Mr. Burns: And if it's a crime to bribe a jury, then so help me, I'll soon be guilty of that!
Homer: (stands up to salute) God bless America!
- Skewed Priorities: Homer has just a few minutes to file his tax return and won't stop for anything... other than a hot dog.
- Suicide Pill: Homer almost takes his when he thinks Mr. Burns is onto him. He considers taking it again when Burns tells him they're going to walk.
- Taxman Takes the Winnings: There's one scene with the Sea Captain taking a necklace from a treasure chest and placing it inside an envelope while waiting for his turn to mail his tax forms. He's wondering why he bothered to pillage that treasure.
- Tempting Fate: While showing the big lines of people who waited until the last day to file their tax returns, Kent Brockman isn't worried because he'd previously sent his tax data to an accountant. Said accountant then shows up and is just as worried as everybody else.
- The IRS film in the photo booth at the mall can be seen by anyone just by saying "Cheese!", as Apu demonstrates when he goes into the booth after Homer and Agent Johnson leave.
- This Page Will Self-Destruct: The film the IRS shows to Homer ends with "This film will self destruct... if improperly stored."
- Vacation Episode: Homer, Smithers and Burns travel to Cuba in the final act.
- When the Clock Strikes Twelve: The post office closes at midnight and everyone who waited until the last day to file their tax return must do so until then.
- Zillion-Dollar Bill: The trillion dollar bill meant for the reconstruction of Europe after WWII, but pocketed by Mr. Burns.