1 night in vicious hoodlum Blackie, the New Orleans slums and his pals kill an illegal immigrant who won much into a card game. Next morning, Dr. Clint Reed of the Public Health Service confirms the dead man needed pneumonic plague. Clint inoculate and must find the natives as well as their partners, with the aid of authorities captain Tom Warren, despite skepticism that is official, and in secrecy, lest the metropolis empties to protect against a catastrophic outbreak. Could a doctor ? He's got 48 hours to take to...