Homer (like most of us in RealLife) 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-WorldWarII Europe to pay for damages done to the cities and stimulate the economy.

!!Tropes:
* AllOfThem: The reasons for visiting Cuba are: business/pleasure; smuggle cigars; assassinate Castro. Homer checks all of them.
* BoxedCrook: Homer agrees to work as an IRS snitch to avoid going to jail.
* TheDeadRiseToAdvertise: A billboard of Che Guevera is seen advertising Duff Beer.
* DiscoDan: 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, has no idea Batista was no longer in power.
* DoesThisMakeMeLookFat: 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.
* DudeWheresMyRespect: Smithers is upset when Mr. Burns doesn't appreciate the dinner he prepared, saying "Sometimes, I don't know why I bother..."
* FrenchJerk: Apparently, this trait started because Burns stole the trillion dollar bill meant for Europe.
* HistoricalInJoke: Mr. Burns has the suit Creator/CharlieChaplin 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.
* IntimidatingRevenueService
* OhCrap[=/=]ThisIsGonnaSuck: The [[http://www.springfieldspringfield.co.uk/view_image.php?tv-show=simpsons&image=s09e20_196 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.
* ThePasswordIsAlwaysSwordfish: 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.
* ScrewTheRulesIHaveMoney: How Mr. Burns intends to avoid punishment.
--> And if it's a crime to bribe a jury, then so help me, I'll soon be guilty of that!
* SuicidePill: 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.
* ZillionDollarBill: The trillion dollar bill meant for the reconstruction of Europe after WWII, but pocketed by Mr. Burns.