This film about a woman who returns from Cuba to New York City with both smuggled diamonds and smallpox is a fairly typical film-noirish melodrama of the late 40's/early 50's. Will the police and Health Department officials find her in time to save NYC from an epidemic? The film has all the elements one expects from this type of film: great black and white cinematography, romantic subplots, over-the-top shady characters (one played by Jim Backus, "Mr. Howell" of "Gilligan's Island" fame) and too-good-to-be-true good guys, and great New York locations. It also has a hammy narration and some corny dialogue, but it is a fairly suspenseful and generally fun way to spend 75 minutes.
However, the situation which probably seemed like far-fetched (but plausible) fiction in 1950, seems frighteningly possible today. The anthrax attacks of 2001, the fears of weaponized smallpox being used by terrorists, the concerns about vaccinations and the amount and safety of vaccines, the inability of governmental agencies to work together and share information effectively all come to mind when one watches this film. This gives it a bit more resonance today than other more dated noirish "chase" films of the same era.
Overall, only a pretty good film but definitely worth a watch for the subject matter and its relevance to today's fears about bio-terrorism.