After Mr. Burns gets teased about his old car by the kids at Springfield Elementary, he sends Homer to pick up a brand new Lamborgotti Fasterossa car in Italy. The rest of his family goes along with him and they fly over on Alitalia. After they pick up the car, they have a great time touring the country. During the trip, Homer and Bart manifest limited knowledge of the history of Italy and the Italian language. After a huge wheel of Mortadella lands on their car, they slowly push it into a small Tuscan village nearby called Salsiccia, which means sausage in the Italian language. When they get there, they ask an elderly woman for help, and she tells them that the mayor speaks English. The Simpsons find out the mayor is none other than Sideshow Bob. They are shocked to find him there, and he feels the same way. Bob explains to them that after he attempted to kill Bart, he decided to get a fresh start elsewhere by settling on his new destination of Italy. After a rough start, the natives warm up to him after he helped them crush grapes into wine (using his enormous feet). After that, they elected him mayor of their tiny village. Bob no longer has any intention of killing Bart, and it is revealed that he has a wife and son, Francesca and Gino, who know nothing about his past life in America. Bob begs the Simpsons not to tell anyone, and they agree in order to have the car fixed.
The Simpsons enjoy spending time in the village, and they continue to keep Bob's past a secret. However, when Lisa gets intoxicated at a party, she starts to reveal awful truths about him being an attempted-murderer to her brother, Bart. He leads her away from the table, but as she stumbles backwards, she rips off his suit and everyone can see that underneath is his prison uniform. The village finds out the Bob is an attempted killer, and they sack him as Mayor. The Simpsons take off in the fixed car, and Bob swears vendetta on them.
When the family flees, Bob follows them on a motorcycle. Homer drives into a ditch and drives onto a Roman aqueduct. When they fall off the end of the aqueduct, the car lands on top of Trajan's Column in Roman Forum. Bob's wife and son meet him, and Francesca tells him that they will kill the Simpsons together as a family.
Meanwhile, the Simpsons are wondering what they should do next, since they are in a foreign country, have no car and no money whatsoever. Lisa spots a bus with a poster advertising Krusty the Klown's performance in Pagliacci. They meet up with him at the Colosseum, and he puts them in as un-noticed extras. However, Bob, Francesca and Gino find them and corner them on the stage while Krusty, who went through a trap door, flees the stage, allowing Bob to perform the climax of Vesti la Giubba. Before Bob and his family could finish off the Simpsons, though, Krusty's limo picks them up. Krusty needs them to smuggle an ancient artifact back to America. The Terwilligers walk away, grinning maliciously and plotting revenge.