With his work on 2008’s Milk, screenwriter Dustin Lance Black managed to pull off the rare feat of crafting a quality biopic that’s actually quite memorable. In part, he did this by focusing on the most-interesting period of his subject’s life, rather than fashioning a cradle-to-the-grave narrative. However, his work on director Clint Eastwood’s J. Edgar, a sweeping profile of the longtime head of the FBI, isn’t anywhere near as good. Sadly, this movie makes seemingly every mistake that Milk so adroitly avoided. Starring Leonardo DiCaprio as the titular lead, the movie follows three different threads of the man’s historic life. First, the movie ambitiously chronicles the highlights of Hoover’s 50 years as the head of the FBI, focusing on his resolution of the Lindbergh baby kidnapping and his apprehension of a number of famous bank robbers; secondly, the film attempts to provide some insight into Hoover’s psychological makeup, especially how his mother influenced him; and thirdly, it tells the purported doomed love story between the severely repressed Hoover and his longtime second-in-command Clyde Tolson (Armie Hammer). While these storylines begin promisingly, they ultimately run out of steam and fail to cohere into a great movie. It’s fun to watch the young Hoover (a real-life Joe Friday “just the facts ma’am” law enforcer if ever there was one) create the FBI out of his own flawed self-image -- a group of mentally and physically fit selfless servants who put the good of their country above all else. And when his mother (Judi Dench) lets him know in no uncertain terms that she’d rather have a dead son than a gay son, the moment has real bite because we’ve seen how much he cares for Tolson, whom he handpicks as his second-in-command. There is nothing obviously wrong with the production of the film. The actors are all solid, the period costumes aren’t showy, and although there are a couple of scenes in which the old-age makeup on DiCaprio and Hammer could be described as “unfortunate” (there’s a scene at a racetrack where an elderly Tolson looks like a liver-spotted Voldemort), it’s by no means a constant distraction. J. Edgar falls apart because it never builds any storytelling momentum; it plods when it should flow. There are a few good individual scenes -- a date between Hoover and Helen Gandy (Naomi Watts), the woman who would become his personal secretary for nearly half a century, shows us Hoover’s social awkwardness and might be the only point when we feel sympathy for him -- and Hoover’s first meeting with Tolson is so pure an expression of love-at-first-sight that it verges on parody. But none of these promising early scenes are elaborated on. It’s as if Eastwood trusted that the sheer weight of history would give the film an inevitable depth, that its greatness would be obvious. But the movie is dull for long stretches, and the final scenes, when they arrive, don’t have any dramatic pull at all. As you stare down at Hoover’s corpse in the movie’s last scene, you ponder not how he got himself to that point, but how the film manages to make such a fascinating figure so uninteresting.