Gene Kelly as an Italian-American attorney? Once you get past this, the rest of Black Hand ought to go down easy. This expose of organized crime is set in New York's "Little Italy" the late 19th century. The various Italian immigrant merchants find themselves at the mercy of the Black Hand, a group which extorts money upon threat of death. Seeking vengeance for the mob-dictated murder of his father, Kelly tries to gather evidence against the Black Hand. He is frustrated in his efforts until he teams with Italian/American police inspector J. Carroll Naish. Though Naish is eventually murdered while assembling evidence, he is able to mail his findings to Kelly, who, after beating crime boss Marc Lawrence to a bloody pulp, delivers the guilty parties to the authorities. In the real-life incidents upon which this film is based, it was the Mafia, not the Black Hand, who functioned as the villain. Even in 1950, however, Hollywood had to tread gingerly whenever dealing with big-time crime; it was easier (and safer) to go after a "dead" criminal organization than a "live" one.
by Hal Erickson synopsis