The Town (15)

Ben Affleck, once the joke consort of a celebrity prima donna, has put his head down and proven himself not only a better actor than we thought but a director of some finesse. He performs both functions in The Town, a lean, mean crime drama set in the working-class Boston neighbourhood of Charlestown, home, it is reckoned, to more bank and armoured-car robberies per annum than any other square-mile neighbourhood in the US. Robbing banks is almost a trade round here, passed down from father to son like trawling, or dry-cleaning. It's just a different set of risks and rewards.

Affleck himself plays one such felonious scion, a tough-nut named Doug MacRay who's the planner for a local gang of hoodlums. The sensational heist they pull off in the film's opening scene tells you immediately that, first, they are ruthless, and second, they've done this a few times before. Faces shielded by ghoul masks, the four robbers burst into the bank and instantly establish their control of the space, terrorising customers and staff alike before forcing the bank manager to open the vault. This would be Claire (Rebecca Hall), who is briefly taken hostage by the gang as they make their getaway, and later released.

The Town, adapted from a novel (Prince of Thieves by Chuck Hogan) by Affleck, Peter Craig and Aaron Stockard, does not distinguish itself in terms of originality. It is unequivocally a genre picture, but it treats its component parts with the same respect and attention to detail that Affleck brought to bear on his debut feature Gone Baby Gone (2007), especially in the depiction of Boston lowlife. Never having been to the city I can't vouch for the degree of authenticity, yet it feels deeply rooted in a sense of place, in a style of speech, and in a type of character. Take Jem, for instance, Doug's lifelong friend, who's done a nine-year stretch and has the tattoos to prove it: you can practically smell the prison yard on him. As played by Jeremy Renner, hot from The Hurt Locker, he's a wild card whose propensity for violence rests on a hair-trigger. It was his not-very-bright idea to take Claire hostage, and once they discover that she's a resident of their neighbourhood Jem insists she'll have to be watched – or something worse.

Knowing what his friend is capable of, Doug takes on the job of tailing her, and after an accidental encounter at a laundromat they start to fall for each other, Claire little realising that she's met him before, at gunpoint. The idea of bank robber and victim tangled up in romance sounds barely credible; but in a movie it doesn't have to be credible, it just has to be convincing, and Affleck gives us enough of a character here to make it so. Doug, half-choked by disappointment – he could have been a pro-hockey player, but then took a wrong turn – has had enough of knocking over banks and the dead-end brotherhood of felons. Even his on-off girlfriend (Blake Lively) is Jem's sister. In Claire, a "toonie" interloper a few notches above him in class, he may see his last chance of escape. Hall is pleasingly tentative for one so beautiful, seeming not quite at ease as a willowy brunette, and the irony of her situation keeps digging us in the ribs: "I'm sure I'd recognise their voices," she says to Doug of the bank robbers, betraying her imperfect ear. But she plays the fooled with conviction.

The cast is just as strong in the less fleshed-out roles, though the Federal bruiser who's in pursuit of the gang will give fans of Mad Men pause. He's played by Jon Hamm, and the eye takes a while to adjust to him in his drab windcheaters and check shirts rather than Don Draper's natty 1960s office-wear. The ear, too: it's the first time I can ever recall hearing Hamm swear on screen. Chris Cooper, as Doug's jailbird dad, only gets one scene, but it's all he needs to convey a lifetime of unforgiven absence. I loved the father's parting shot to his son, about to take on the most dangerous heist of his life: "I'll see you again," he says through the prison glass, "this side or the other". You can't tell whether he's speaking of jail or the afterlife.

As the film gathers towards a denouement you may notice a lapse or two into platitude. I never thought to hear the phrase "You're like a brother to me" in any movie, let alone one as fine-tuned as this. And there's the cordite whiff of old-crime machismo in Doug's vow that this will be his last score. Then again, Affleck is smart enough not to fall for the St Patrick's Day bagpipes-and-drum parade as a setpiece, without which no Boston crime flick used to be complete. As a director he runs a tight ship, and delivers long action sequences with some elan. He's learnt the staging of bank raids from the best – Kathryn Bigelow's Point Break for kinetic energy and Michael Mann's Heat for running street battles, and that relentless feral clatter of bullets hitting metal. I'm afraid there is still a cherished place for that moment in a movie when the jig is up and all that remains is for cops and robbers to blast away at each other, particularly when the latter are disguised as nuns. Nuns with guns! Slap that on the poster and I'd go and see it.