Dr. John Petrie is sent to Mozambique to determine if Big Syd Vesta, an American gangster who is on the lam, is sufficiently healthy to return to the United States to stand trial. With Dr. Fu Manchu's help Vesta fakes his death. In return Vesta uses his connections with U.S. organized crime elements to stage a string of bank robberies all as dress rehearsals for their biggest crime - robbing the six biggest banks in New York City simultaneously.