The basic premise for this wonderful comedy is the strange customary tradition between father and son, Alberto, wherein the son has to pay the father a designated amount of money for his "debt" to him (the debt of a child to a parent). Nino Manfredi is wonderful as the father. Most of the movie takes place on a train, the Paris to Rome Express, which Alberto rides home to return to his pregnant wife. This is where the fun begins. All the characters on the train seem geared toward helping or preventing Alberto from his goal of raising the money to pay his father. He tries stealing their valuables, but loses the whole bundle of loot in a crazy adventure on the top of the train. There are some wacky and wonderful scenes with various characters; like the guy who lets Alfredo steal all of his things because none of them belong to him, or the dream-type sequence in the rear car where he talks with all of his ancestral grandfathers. This movie has one of the funniest lines I've ever heard in any movie; there's a scene in which Alberto is questioning a friend on his goals in life, and part of their conversation leads to discussing famous last words -- the line went something like this, "Remember Gogol's last words... 'A ladder! Quick! A ladder!'" I don't know exactly why, but I laughed hysterically at that line. The train ride culminates in Alberto returning to Rome with no money. He finds out his father is a cab driver, so he goes to where the taxis wait, gets into his father's cab (keeping his identity secret for the moment), and they drive off. The father (Manfredi) finds out his son is in the back, nearly wrecks the car, then they discuss the famous "debt". I should tell you the ending, because it's a wonderful twist, but then I would ruin it for you. Even if you don't like foreign movies, I highly recommend this one. Italian/French/English with subtitles.