One night in New Orleans, the hooligan Blackie shot Kochaka with his friends because he had a conflict with illegal immigrants. After the body was found, Dr. Clint Reid of the Public Health Bureau determined that the victim had a lung disease. In order to prevent the outbreak of a large-scale epidemic without causing panic among the public, all those who had been in contact with the dead must be found secretly within 48 hours. Dr. Clint and the police chief, Colonel Warren, conducted an urgent investigation. At the same time, Blackie suspected that his accomplice had betrayed him, and there were entanglements among the bandits.