A secretive cadre of crime - The Black Hand - has tightened its grip on New York City's Little Italy of the early 1900s. Merchants are threatened, some horribly beaten. Citizens cower in fear rather than testify about crimes they've witnessed. And everyone dreads the extortion notes that say Pay or Die. But police lieutenant Joe Petrosino is determined to end the spree of terror. He sets up a special squad of investigators, systematically attempts to root out the criminals and makes a discovery he never expected: The Black Hand is directly tied to the Mafia. Ernest Borgnine plays Petrosino in this hard-hitting, fact-based crime saga directed by Richard Wilson, who created a stir the prior year with the gangster saga Al Capone (starring Rod Steiger).

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.