The film tells that in 1979, the second-generation godfather Michael Corleone was in his twilight years. In order to save his soul, Michael slowly ended his family's underworld career and switched to legitimate business.
Michael's son Tony studied law in college, but he didn't want to be a lawyer and loved the art of opera. Michael decided to let his eldest brother Sonny's illegitimate son Vincent inherit the family business and become the third-generation godfather. Vincent is a very scheming man. He obeyed Michael's words, so he liked him very much. But he is also a lascivious. While he had a tryst with the female reporter, he pursued the godfather's daughter Mary on the other. But Michael does not allow Vincent to marry his daughter because the mafia canon prohibits him from marrying. For this reason, there was a conflict between Mary and her father. The two sides are estranged.
In order to redeem his soul, Michael wanted to transfer the illegally earned assets to Europe to legalize it. He implemented this plan through his network of connections in the Holy See in the Vatican. When the Vatican Bank saw a huge deficit, Michael believed that the opportunity had come.
When Michael agreed to inject capital into the Vatican Bank and asked to obtain control of the European real estate group controlled by the Vatican Bank. Li Li's controller, Lugasi and the archbishop, deceived Michael, took the money and refused to give up Li Li, and attempted to use them to assassinate Michael.
In order to eliminate the last few enemies, Michael sent his men to track down New York and Sicily. However, when he watched the opera performed by his son Tony with his returning wife, Kay, a bloody carnage happened beside him. The new pope was assassinated. A group of gunmen flooded into the opera house. During the gunshots, Michael escaped from the dead, but his wife died because of accidental injuries. Power brought Michael to the pinnacle of glory, but power also sank Michael into the abyss of evil. He finally reached the end of the road, and gradually left this bustling and noisy world in regret and despair.
