1 night at vicious hoodlum Blackie the New Orleans slums and his friends kill an illegal immigrant who won too much in a card game. Next afternoon, Dr. Clint Reed of this Public Health Service affirms the dead man had pneumonic plague. Clint inoculate and must find the natives as well as their associates despite skepticism that is authorized, and in complete secrecy, lest the city empties to protect against a devastating outbreak. Can detective turn? He's 48 hrs to decide to test...