In the continuing saga of the Corleone crime family, a young Vito Corleone grows up in Sicily and in 1910s New York. In the 1950s, Michael Corleone attempts to expand the family business into Las Vegas, Hollywood and Cuba.

The magistrate, Scauri, inquires into the mysterious poisoning death of Gaspare Pisciotta, the imprisoned assassin of Salvatore Giuliano. He very soon finds himself struggling against a conspiracy of silence, which Scauri must therefore overcome in order to indict two powerful mafia bosses. His only hope comes for a brief moment from the testimony of the young prosecutor Lojacono. But The Organization is the most strong: the young prosecutor withdraws his deposition and the magistrate disappears in mysterious circumstances.