In order to avoid an audit, Homer serves as an IRS spy in a sting operation targeting Mr. Burns. We learn that, many years earlier, a younger Burns was entrusted with the task of delivering the only one trillion-dollar bill ever minted to a shattered post-war Europe. The government's logic was that America's wealthiest man would never steal the money; of course, they were wrong. Now it's up to Homer to recover the trillion, but when he realizes that he's working for the agency that has exploited him all these years, he joins up with his boss and flees to Cuba with the money. While there, Homer, Burns and Smithers meet with Fidel Castro, who swipes the trillion-dollar bill and sends the men packing. Floating back to America on a refugee raft, Burns decides that he'll simply buy his way out of this most recent problem and everything returns to normal.