It may seem difficult at first to recognize David Mamet's distinctive voice within the decorous and discreetly mannered period surface of The Winslow Boy, his masterful adaptation of Terence Rattigan's 1946 stage play. Better known for his coarse, piercing urban dramas (Glengarry Glen Ross, American Buffalo) and Hitchcockian sleights-of-hand (House Of Games, The Spanish Prisoner), Mamet had previously limited himself to directing only original screen work in contemporary settings. But much like Martin Scorsese did with his powerful (and similarly unexpected) The Age Of Innocence, Mamet visits a foreign and rigidly defined world and makes it unmistakably his own, fully integrating his staccato rhythms of speech and subtly calibrated dissections of class and gender. Based on a real-life case in 1912 England, The Winslow Boy concerns a 13-year-old naval cadet's expulsion from school for stealing and forging a classmate's five-shilling postal order. In a riveting and quietly heartbreaking performance, Nigel Hawthorne plays the boy's father, a well-established man determined to clear his name, no matter the expense to his family and his country. He enlists the services of Jeremy Northam, a high-priced lawyer who takes this minor case to unprecedented levels, since no one had ever been able to sue an institution considered part of the king's domain. Though the story begins on the simple bond of trust between father and son, it grows more ambiguous with time, as Hawthorne's unrelenting quest for justice becomes as self-important as it is courageous. Rather than "opening up" Rattigan's play for the screen, Mamet uses the insular confines of the family's home to heighten their myopia, and editorial cartoons to suggest the media frenzy outside. He also coaxes peerless performances from his ensemble cast, including Gemma Jones as the boy's suffering mother and wife Rebecca Pidgeon as her feminist daughter. If The Winslow Boy has a flaw, it's that Mamet's style is impeccable to a fault, too cool and remote to have much of an emotional payoff. But since few directors can even approach his level of precision, that's a very minor complaint.