» See the trailer

What drives somebody to take the law into their own hands? Why is our society so obsessed with violence? Who has the right to stand up when something goes wrong? Can murder ever be justified? How many wrongs make a right? Will anybody notice that we lifted our plot from Charles Bronson's '70s exploitation flick 'Death Wish'?

'The Brave One' asks many — usually weighty — questions. But it answers few. Instead the new film from 'The Crying Game' director Neil Jordan opts for a moral ambiguity that's more frustrating than thought provoking.

Blame his own indecision. Lead actress Jodie Foster has described the project as "a very sophisticated movie that lives in a very unsophisticated genre", but that's just an articulate Yale-graduate way of saying "we couldn’t decide if we were making a high-brow drama or 'Die Hard 5'". So they made both — in the process missing each of their target audiences while softening the blows of what could have been a genuinely hard-hitting and insightful character study.

But there's still plenty to recommend. Foster, after a terrible case of miscasting as a glib problem solver in 'Inside Man', returns to what she does best: the damaged but resilient every-person who chooses to fight back when thrown into a situation that would leave others whimpering in a corner.

But as successful radio presenter Erica Bain, the double Oscar winner gets to dig deeper than she did as the desperate mothers of 'Panic Room' and 'Flightplan'. Through her finely measured performance we experience the wholly believable transformation of a joyously content woman into a cold, hard, empty shell of her former self.

As she becomes somebody she no longer recognises, deeply conflicted by actions that go against her own moral code, we begin to understand how an educated, law-abiding citizen whose life is shattered by a brutal murder and attack can become a vengeful killer, armed with nothing but an illegal gun and a hairstyle that echoes Bronson's bouffant 'do.

Foster's richest performance since 'Nell' is almost matched by Terrence Howard as Sean Mercer, the scrupulous New York cop trying to solve the city's recent spate of vigilante killings. Bain befriends the honorable detective under false pretenses, adding a cat-and-mouse will-he-won't-he-catch-her subplot, while peeking into the mind of a dedicated policeman battling to do his job with limited resources.

While the film clips along at a steady pace towards a melodramatic Hollywood finale — pausing periodically for Foster to show her acting range to the Academy — Howard overcomes the clichés of the role (dedication to the job causes insomnia and divorce) with acting as subtle and surprising as the character himself.

"There's a strange dichotomy between the law of nature and the law of man and we try to walk this line," the actor has said of the part. "It's a weird place to sit, wondering who's right and who's wrong."

Just don't expect an answer.