In Center City, a housewife is murdered in a night-club by a gang of thieves. When a security guard of a bank is killed by the same gun during a heist, the crime becomes a federal offense under FBI jurisdiction. When the prime suspect is released and executed in the same night, FBI Inspector George Briggs recruits the rookie agent Gene Cordell to follow the last paths of the victim undercover in the identity of George Manly. Gene meets the powerful gangster Alec Stiles in a gymnasium, and later he is invited to join his gang. Working with his also undercover liaison Cy Gordon, Gene finds evidences to incriminate Stiles. However, he discovers also that somebody from the precinct is feeding Stiles with classified information.
—Claudio Carvalho, Rio de Janeiro, Brazil