Based on real incidents in the life and death of Lt. Joseph Petrosino (Ernest Borgnine) of the New York police force, this tale set between 1906-1909 details the history of the lieutenant's fight to prove Sicilian Mafia involvement in crimes in his city. Lt. Petrosino has a series of dangerous close calls as he distinguishes himself by saving singer Enrico Caruso from a Mafia bomb outside the Metropolitan Opera, and by also saving the father of Adelina (Zohra Lampert) the woman he loves. Several other exploits eventually lead to Petrosino's trip to Sicily to nail evidence for the Mafia's activities in New York, and for a final meeting with destiny. This represented the last screen credit of scenarist Bertram Millhauser, who died in 1958; he had received his penultimate credit nine years before that, on the 1949 Tokyo Joe.