The film is about the first FBI director, J. Edgar Hoover.
The bulk of the story is told in flashback. Sometime in the 1970s, Hoover (DiCaprio) begins recounting his memories to a ghostwriter. He starts with the attempt on the life of Mitchell Palmer, Attorney General, in 1919. The event would place the young J. Edgar Hoover at the helm of a special task force that would later become the FBI. We also meet Helen Gandy (Watts), who would become Hoover's longtime personal secretary and Clyde Tolson (Hammer), a young lawyer. Tolson and Hoover quickly become close friends.
Hoover brings innovation to criminal science, and through a series of successful operations, he and the FBI become household names. His personal life is fraught with trouble though. There are multiple allusions that his strong friendship with colleague Tolson is more than it seems, and his reluctance to settle down and marry fuels suspicions. His mother (Dench), who exerts a strong influence upon his life, does not hide her disappointment.
While on vacation, Hoover and Tolson's relationship reaches a boiling point, with both trading insults at each other. It culminates in an unexpected gesture, which shows that despite the strain put on them, the connection between them is strong enough to weather any storm.
As the years pass, J. Edgar's health begins to decline and he feels threatened from all sides. His actions and methods, using the now powerful FBI organization, are being questioned. He instructs his secretary Helen that, in the event of his death, she must destroy all his private files.
His longtime friend Clyde unsuccessfully encourages him to retire, and eventually, J. Edgar dies in his bed, acting director of the organization he practically created, with Tolson by his side.
Best part of story, including ending:
In the beginning, the story focuses primarily on Hoover's work. As the film progresses we gain more insight into his personal life, and we see how it affects his public persona and his job. The film does a reasonable job in not sensationalizing or glorifying the titular character.
Best scene in story:
My favourite scene is the one between Edgar and Tolson in their hotel room. There is so much unsaid between the two and it all comes out at that point, raw and unfiltered.
Opinion about the main character:
The character has a very firm moral code and a very strong impulse to break said code. This contradiction is gnawing at him and he must also run one of the most powerful institutions in the U.S., a testament to his ambition.