Not surprisingly Clint Eastwood is the kind of director who will give an actor room to explore, waiting a moment when others would cut away. For Leonardo DiCaprio this is licence to give the best performance of his career so far, starring as FBI honcho J Edgar Hoover.
Those moments of silence are golden, especially sandwiched between so many blunt remarks and dry observations about the human condition, which serve him well at crime investigation and yet do nothing to shoo away his own demons. It begins feeling a tad too clinical - like the man himself - but it gradually builds into a powerful study of how an obsessive need for control becomes his own prison.
Edgar might be branded a victim of OCD in the modern parlance, but his meticulous nature and the absence of a social life is what sees him rise so quickly through the ranks of the Justice Department (plus, a useful hatred of lefties). He has a very definite vision of success too, proposing to secretary Helen Gandy (a stern Naomi Watts) after only three dates and a quick rummage in his enormous filing system.
She turns him down, of course, so he offers her a job as his PA after he's given the task of setting up the Bureau of Investigations. There's a more meaningful glint in his eye when he hires chiselled law graduate Clyde Tolson (the debonair Armie Hammer) as his right-hand man.
Initially, Hammer plays Tolson like a puppy dog, following dutifully with wide loving eyes. It's a subtle source of humour made more amusing by the depth of Edgar's denial about his feelings. The reason is laid bare in his relationship with mother, who is played by Judi Dench with equal parts adoration and reproach. Though Edgar strives for her approval, he finds more comfort in science, delighting in new discoveries such as fingerprinting; things that he can record and catalogue.
Still, he wants the love of the masses too, realising the power of PR to elevate his profile, writing his own legend and turning G-Men into comic book superheroes. He hogs the limelight in headline cases like the Baby Lindbergh abduction, a long-running investigation that ups the pace in the middle part of the film.
Wiretapping is another innovation of the Bureau that Edgar exploits to record the naughty sweet nothings whispered by leading politicians, including John F Kennedy. He sits on a pile of secrets so high that even presidents cannot get at him. But what's more engrossing to watch is the growing sense of paranoia that Edgar lives with, and his own secrets burning him up inside.
DiCaprio is masterful, revealing a lack of self-confidence even as he lashes out in monstrous style. Naturally, Clyde is chief whipping boy, but the balance tips as their relationship evolves (chastely, because Edgar is a model of self-control) and, through his eyes, Edgar is humanised. Eastwood shows great sensitivity too, especially in regard to J Edgar's reported cross-dressing habit. The makeup team also deserve credit for stunning transformations illustrating the passage of half a century. But after so many boyish turns this is, above all, DiCaprio's finest hour. Finally, here cometh the man.