If what you want out of a movie is moral clarity -- or even coherence -- you should probably avoid the new Irish gangster flick In Bruges. It's a credit to screenwriter and director Martin McDonagh's clever contrivance to hear critics complain that its superlatively violent ending breaks the moral deal. To paraphrase Arthur Penn, the father of critically reviled ultraviolence, we're killing people every day in Iraq, and you're upset that this movie is too violent?

The film concerns a pair of hitmen, banished from London after a botched job. They wind up in Bruges, "the best preserved medieval city in Belgium." Their reaction to the place is the key to their characters. The older killer Ken (Brendan Gleeson) remains satisfied touring the city with his guidebook, appreciating the architecture, considering the history. Ray (Colin Farrell) finds Bruges boring and doesn't waste an opportunity to say so. He would rather people-watch than sightsee. His mood picks up considerably when there's a midget to talk to, a pretty woman to pursue, or an American to antagonize.

But then again, Ray also has a lot more on his mind than Ken does. Ray is the reason they're in Bruges. He botched the job. He accidentally shot a kid. (The murder of the boy proves to be a pivot of the film; the child's innocence depicted in the list of sins he brought to confession: "1) Being moody. 2) Being bad at maths. 3) Being sad.") And Ray can't live with himself.

Farrell plays the role with a stunted emotional palette. Ray is a manchild deliquent, not a cold killer. And even as Farrell shows the limits of his talent -- he does that weeping thing where it looks like he is chewing invisible gum -- Farrell also makes a case for its existence. He's a character actor who can do vulnerable.

McDonagh is a playwright, and the plot compounds elements and choices until it reaches a certain critical mass of comic inevitability. When Ralph Fiennes enters the picture (behind a tempest of curse words) as mob boss Harry Long, his steely, uptight menace brings a measure of artisanal control to the careening plot. The pause before Harry apologizes to his wife for calling her "an inanimate fucking object" is the breath the film needs before its final bloody sprint -- and the moment we know Harry is done for.

Colin Farrell and Brendan Gleeson play two killers in Martin McDonagh's In Bruges.