Erica Bain (Jodie Foster) is about to get married when her husband is killed during a violent confrontation with several young men from ethnically diverse backgrounds, inside Central Park.

Detective Sean Mercer (Terrence Howard) is investigating a murder he suspects was perpetrated by the husband of the deceased. He also comes to be involved in the investigation of several killings the shell casings show to have been carried out by a single person.

Mercer's first case becomes important when Bain learns of it and takes an interest. She has access to him in a legitimate capacity in her role as a broadcast journalist. But she's also the person doing the killing, dressed in T-shirts and jeans and carrying an automatic pistol purchased on the black market.

Adding depth to this apparently straight-forward revenge fantasy is Carol (Mary Steenburgen) who is Bain's editor and who realises, when listeners start sending comments on Bain's post-traumatic broadcasts, that her star performer has hit a nerve. People are sick of violence.

The modern state has a monopoly on violence and there are good, historical reasons why this is so. But in The Brave One the law is manifestly incapable (as demonstrated in the other case Mercer is working on) of bringing the guilty to justice. It's an indictment.

Who the target of this film is (or are) is not clear, however. But seen in the light of the post-Atta world, things make a lot of sense. If the global watchdog (the United Nations) is incapable of applying its high-minded rules, then someone has to take matters into their own hands.

It's not hard to come to this. And the cross Bain dons following her ordeal, and on the verge of beginning her campaign as a vigilante, is eloquent, if heavy-handed. Combined with the T-shirts and jeans, the shoulder-slung urban tote, and the nightly prowl (she says she can't sleep), this little fashion item tries lamely to hide its original meaning, and intentionally fails.

It's the redeemer in the temple tossing out the tables of the money changers, all over again.

On the plus side, the movie is engrossing on first viewing, but stale on the second. The sexual dynamics between Mercer (who is African-American) and Bain (whose husband-to-be was a black from south-east England, going by the cockney twang) segue into a professional relationship that culminates in Bain shooting Mercer in the shoulder to cover up the trail, so that Bain is not herself brought to justice for her vigelanteism.

In short, it's a fairly subtle take on a topical issue. Following such work as George Gittoes' in Miami, we should hope to see more analysis of the impact the standard post-colonial dialectic has on real lives. Nobody should have to fear a walk in the park.