I'm of two minds regarding "In Bruges," the feature film directorial debut from Irish playwright and screenwriter Martin McDonagh. His subjects are a couple of eccentric hit men on enforced vacation, and along with serial killers with twisted, "imaginative" moral agendas, the conceit of the eccentric, colorful hit man has nearly run its course in the movies.

But McDonagh writes awfully sharp dialogue, and he has the good dramatic sense to bring the "cool" factor down a few pegs. These hit men are working-class fellows who do not dress stylishly.

And after playing one too many sullen poseurs, it's clear Colin Farrell and Ralph Fiennes had a ball making an inky black comedy seething with grandiose invective.

The Mutt/Jeff/Laurel/Hardy act this time belongs to Farrell, who plays itchy, manic-depressive Ray, and his older, calmer partner, Ken, played by Brendan Gleeson. (Gleeson acted in McDonagh's Oscar-winning short film "Six Shooter.") The specifics aren't revealed early on, but something has gone horribly wrong in London with the boys' recent job. The boss is displeased. He's Harry, played by Fiennes, doing a droll East Ender dialect and going on about not needing an Uzi because, after all, he's not a South Central L.A. gangbanger.

Harry dispatches the two to Bruges to "await instructions." Faced with a couple of weeks' enforced vacation, Ken becomes a passionate tourist. Ray turns more and more exasperated with his colleague's enchantment, and he picks fights with American tourists just for sport. The canals and bell towers mean nothing to him. The enticements of a local prostitute (Clemence Poesy) serve as a potential distraction, along with the novelty of a film crew shooting a movie on location.

When McDonagh clobbered the London theatrical scene a decade ago with "The Beauty Queen of Leenane," it was clear he drew his inspiration from lots of sources, from the richly embroidered language of John Millington Synge ("The Playboy of the Western World") to the pulp and gristle of cinematic crime fiction. "In Bruges" owes a considerable debt to Harold Pinter's early play "The Dumb Waiter" (two killers, awaiting instructions, killing time) and, as with Pinter, the banter is very much the thing here. McDonagh lets his killers go on, amusingly, about the strangeness of being shipped off to Bruges from London. Why Bruges? "It is a bit ... over-elaborate," says one of them, pondering their fate. Later, after a particularly hurtful insult: "You retract that bit!"

The best of "In Bruges" tends to be the most overtly comic, such as a dwarf-clobbering, coke-snorting melee set in a cramped hotel room, or the mournfully understated musings of Ken as the pair take a canal boat tour. Carter Burwell, who works with the Coen brothers, contributes a sad and beautiful little musical score, teasing out the dread and loss in the killers' hurry-up-and-wait circumstance.

Does the violence, which certainly has its outlandish moments, carry a "moral" core? This is the question with McDonagh. He's trying to take the horrific consequences of Ray's on-the-job fiasco seriously, yet the film's comic streak will have only so much of it. Also, the climactic shootout is clearly the work of a novice film director - McDonagh will surely get more fluid and proficient with action sequences in time. Handling physical violence wasn't David Mamet's strong suit on screen, either, early on. It still isn't. But like Mamet, McDonagh has an ace up his sleeve: His characters come up with some real lulus when it's their turn to talk.