As the lukewarm critical reception suggested, J. Edgar falls somewhat short of the powerhouse drama and awards glory that many of us had it pegged for. After all, we are talking about a J. Edgar Hoover biopic directed by legendary filmmaker Clint Eastwood and starring golden boy Leonard DiCaprio. But while it’s often sluggish as the narrative ping-pongs back and forth through the years in low-key, de-saturated fashion, Hoover makes for such a fascinating subject matter that Eastwood’s bio-drama can’t help but prove compelling in sporadic bursts.

Charting his life and times, the movie bounces between him dictating his memoirs as a old man and shaping law enforcement during his younger years. Presented here as an unreliable narrator, Eastwood paints the FBI’s first – and most infamous – director as both the Grandaddy of modern crime-fighting and as a sympathetic monster. On one hand he was a driven visionary who revolutionised policing methods beyond measure, and on the other he was a petty tyrant who started to believe his own myths.

As interesting as it is to watch his ascension to power and the accompanying descent into obsessive paranoia though, the movie’s stand-out scenes deal with his impotent personal relationships. A couple which spring to mind involve Judi Dench’s domineering mother (such as Hoover trying on her clothes or his swiftly-deflated attempt at coming out), but more important is an explosive, overdue argument with right-hand man Clyde Tolson (Armie Hammer). Given the notorious questions surrounding Hoover’s sexuality, it comes as little surprise that his relationship with Tolson functions as the heart of the movie. And it’s this scene, where the deeply-closeted FBI chief rejects the love of his life, which proves the most affecting.

DiCaprio is perhaps an odd choice for the asexual mother’s boy (imagine what Michael Shannon could have done with the part), but yet he’s too accomplished an actor to deliver anything other than class. Even if, like Hammer, he spends half the film hidden under liver-spotted, old man make-up which is never really convincing. Elsewhere, Naomi Watts has very little to do as Hoover’s faithful secretary.