A movie with the often-brilliant British actor Tom Hardy, Noomi “The Girl With the Dragon Tattoo” Rapace and the final film performance by James Gandolfini? A screenplay by Dennie Lehane, his first time adapting his own work? All of it directed by the guy who gave us “Bullhead,” one of the most savage neo-noir’s in recent memory? In the immortal words of Kenny Bania on “Seinfeld,” “That’s gold, Jerry! Gold!”

The reality is more complicated and more disappointing.

It is Brooklyn circa now, gorgeously shot by cinematographer Nicolas Karakatsanis. It’s not the Brooklyn of 20-somethings on fixed-gear bikes but the Brooklyn of Chechen mobster-controlled dive bars and the mopes who work them.

As Hardy’s voiceover tells us, “The Drop” refers a “drop bar,” a spot where gangsters drop off ill-gotten cash throughout the evening to be collected at the end of the night. Hardy plays Bob Saginowski, a slow-witted bartender at one such establishment and the cousin of the bar’s former owner, Marv (Gandolfini).

Both men were wannabe gangsters, but when the Chechens stepped in, Marv found out he wasn’t as tough as he thought he was and lost his bar. Now Marv just runs it, a bitter man who lives with his sister (Ann Dowd) and counts other people’s money. Bob just tends bar.

On his way home one night, Bob finds a bloody, abused puppy in a garbage can belonging to Nadia (Rapace), a cute little dog who should obviously be named “MacGuffin.”

Bob agrees to take the dog home but seems more interested in Nadia, who seems vaguely distracted the whole time. The two strike up a friendship, a friendship that is clearly being observed by a third party. (And yes, this is an allegedly tough, gritty movie in which a cute dog being menaced is a primary plot device.)

As they must, these two threads intertwine. The bar is robbed, Nadia’s brutal ex-boyfriend (Matthias Schoenaerts) enters the picture, and a Brooklyn cop (John Ortiz) starts looking at old case files and connecting some dots. Those guns from act one have to go off sometime. There isn’t much on-screen chemistry between the miscast Rapace (she struggles with the Brooklyn accent) and Hardy, but there are witty moments between the two of them and especially between Gandolfini and Hardy.

Sure, there is not much in “The Drop” you have not seen before, but that is not the primary problem. (Genres have conventions; it’s how you execute them that makes all the difference.)

No, the problem is Hardy or, more specifically, how Belgian director Michaël R. Roskam uses him. In fairness, Hardy is often an atavistic on-screen presence (“The Dark Knight Returns,” “Warrior”) but he is more than capable of turning the volume down (he was one of the only watchable things in the “Tinker Tailor Soldier Spy” remake). There isn’t much he can’t do.

But all too often, it is impossible to tell how dim-witted Bob actually is; his intellect seems to change with the scene. With his stunted gait and continuous mumble, there are moments when Bob seems mildly mentally disabled, perhaps brain-damaged from an earlier trauma.

But then there are also moments when Bob possesses exceptional emotional insight. Talking to another character about a possible crime, Bob asks, “Are you doing something desperate? Something we can’t clean up this time?” That is extremely unexpected coming from the guy we saw earlier. And if it’s a put-on, it’s not even consistent that way, either. Bob seems no different in private than in public.

Where did this frustrating movie go wrong? There are multiple possible choke points. This is Lehane’s first script, adapted from his short story “Animal Rescue.” “The Drop” is also Roskam’s first English-language movie.

Then again, the old saw is that it’s hard to play a character smarter than you actually are. Here, Roskam asks Hardy to do the opposite, which is at least as difficult; it’s a tightrope walk. In spite of a Herculean effort on Hardy’s part, he never sticks the landing completely. Since “The Drop” revolves around Bob, it falls with him.