Presented in a docudrama style representing Rosi's notion of cine-inchieste (investigative cinema), the film searches for the truth behind the legendary Mafia boss.
Sicilian-born Charles "Lucky" Luciano rises to become "the boss of all bosses" of the American Mafia in the 1930s. When imprisoned, Luciano offers his services to military intelligence, receiving a commutation from New York Governor and subsequently being deported to Italy. Settling in Naples, Luciano takes control of the underground drug trade. Federal Bureau of Narcotics agent Charles Siragusa is assigned to bring down Luciano, managing to turn his associate Gene Giannini informant. Giannini spends a year in an Italian jail, staying in contact with Siragusa by sending letters through his mistress. However, she has begun an affair with Luciano who thus learns of his friend's double-dealing.
"Many of my films - such as Salvatore Giuliano, Hands Over the City, Lucky Luciano and The Mattei Affair - are structured as investigations into the relationship between causes and effects. /.../ My films are not detective stories, or thrillers, but instead aim to provoke, to raise doubts, to challenge the official statements and certainties from the powers that hide real interests and the truth." (Francesco Rosi)