In "The Reckoning," a troupe of 14th century traveling actors abandon their standard Bible-story fare while visiting a small fiefdom in order to reenact the recent murder of a local boy, and discover in the process that the official version of events is a cover-up for something far more disconcerting.

Having an outsiders' perspective, the players can sense something amiss with the local Church-based justice, and one of their number -- himself a disgraced priest on the run played by Paul Bettany -- feels compelled to investigate. A mute, wild-woman healer (and thus a suspected witch) is scheduled to hang for the crime, but what he discovers leads the actors to risk their lives to expose the truth by presenting a play based on the facts.

Unfortunately, writer Mark Mills (who adapted Barry Unsworth's novel "Morality Play") and director Paul McGuigan utterly fail to address one fundamental problem with their story: What makes them think the people of this village would pay to see the still-fresh horror of a child's brutal murder fictionalized for them like some Middle-Ages Movie of the Week?

Inexplicably the townspeople flock to see these strangers play out events they barely understand, heckling them for their factual inaccuracies. More inexplicably they come back the next day and pay again to see an updated version, after Bettany and troupe leader Willem Dafoe (inexplicably sporting his American accent) have dug up some evidence implicating local priests and the town's royal patron (a action-flick-smarmy lord played by Frenchman Vincent Cassel) in much more than just murder. And even more inexplicably, the actors get away with it, despite dozens of guards sent to stop them.

As the very crux of the plot, this strained contrivance is an unfortunate, insurmountable hurdle for a movie that otherwise has quite a bit going for it, including a palpably realistic, misty, muddy period grit through which the troupe's small wagon rolls, and a fine performance from Bettany ("Master and Commander," "A Beautiful Mind"). He fully embodies the newly rattled soul of this sullied man of the cloth who has a hidden past that includes grave crimes of his own.

Accent aside, Dafoe is equally dynamic as the actor who persuades his reluctant compatriots to break with hundreds of years of Biblical-theater tradition and put on such a daring production, even if he's given a hammy line with which to do it: "I believe this is the way plays will be made in times to come."

But while McGuigan -- who directed Bettany to seething brilliance as a ruthlessly ambitious cockney mobster in "Gangster No.1" -- has a strong grip on the film's acting and ambiance, he sometimes seems too enamored in the artfulness and not concerned enough with other aspects of the storytelling. Demonstrating his priorities are several spotlight-in-shadows shots that indulge a half-naked Dafoe's ability to perform unnerving body contortions. Meanwhile a rather arbitrary (obligatory?) attraction remains half-formed between Bettany and Dafoe's costume-mistress sister, and the talented Brian Cox ("The 25th Hour," "The Bourne Identity") goes to waste in a minor role as the troupe's fuddy-duddy old-timer who longs for the olden days with rhetorical lines like," When I think of the respect our profession used to command..."

The interesting logistics of Bettany's investigation -- and the fact that he alone, as an educated man with certain priestly insights, could expose the truth of the crime -- get lost in the unlikelihoods of "The Reckoning." Had they remained clear, the film might have had the narrative strength to navigate its failings.