The film is a chronicle of forty years in the life of FBI director J. Edgar Hoover, starting first in the time of Prohibition, as he enforced the law on bootlegging and organized crime. Later, the director comes up against the Red Scare of the 1950s, the Kennedys, the wave of change in the 1960s, and his hatred of Dr. Martin Luther King, Jr. Examined here is the allegation that he had an 'abnormal' sexual life, along with his obsession with his dead mother.