- "After promising Marge the trip of a lifetime, frugality gets the better of Homer when he makes a deal with a travel agent to be a courier of a top-secret briefcase in exchange for a discounted family vacation to Paris."
In Stone age (50.000 years ago), Simpsons family lookalikes show "The Invention of Motherhood", where Marge tries to keep Homer, Bart, Lisa and Maggie under control with their shenanigans. Moving to the present day, the same thing is happening at the Simpson House, and Marge tries to convince Homer to do his chores. In the garage, Lisa finds a rare Morgan Motor vehicle, left by the previous owner of the house and Homer decides to keep it.
Marge later in bed confesses she's not happy with her life and Homer seizes an opportunity to cheer her up when he sells to Jay Leno his newly found car, and gains enough money for a trip. However, Leno soon returns and asks for his money back, claiming the car wasn't registered to him and the police impounded it. Unfortunately for him, Marge has already decided on the trip to Paris and is very happy.
To avoid depressing her more, Homer tries to find a way to go to Paris at a travel agency, the cheapest way. The agent offers him to smuggle a package, which he must not open and peer inside to see its content. On the plane, he opens it, finding a blue snake. Lisa finds out it's an Amazon Blue Constrictor, a rare and endangered species. Homer promises her not to make anything bad happen to it, while Lisa promises to help him preserve his marriage.
Upon delivering the briefcase, Homer finds out that the snake would be turned into a belt. Lisa and him escape from the airport and try to set the snake free on the gardens of The Louvre. However the contractors find them and chase them to Rue des Lombards, where Homer and Lisa hide in one of the three main jazz clubs.
Meanwhile, Marge, Bart and Maggie are enjoying Paris' restaurants, but when Marge finds out that everything is made crudely, she asks Bart to dump the food on an alley. After placing down the plate, Bart finds out it's an alley with starving paper-thin models of the Paris Fashion Week. Bart proceeds to prank them by making them chase a sausage on stage, where they get sucked up.
Later in the evening, Homer and Marge go on a stroll and enjoy Paris. Homer confesses to Marge about the snake, and that he did it to make her happy. Back at the hotel they get arrested by the police (comprised of french Chief Wiggum, Eddie and Lou doppelgangers), after the contractors called them. The police searches the briefcase and the entire room but finds nothing, and they free the family. After everybody leaves, the snake gets out of his hiding spot on Marge's hair. Homer and Marge then share a romantic kiss.
The episode ends back in Springfield, where Homer gives Lenny, Carl and Moe gifts from the trip at Moe's Tavern, including a belt made of blue snake, that he says is probably artificial. The episode shifts back to the Stone age, showing a pre-historic Matt Groening signing the drawing of the scene at Moe's Tavern.