Who would have thought that this year's best British film would come from an American director? A witty Agatha Christie-style murder mystery influenced in part by Renoir's “La Règle Du Jeu,” “Gosford Park” is irreverent septuagenarian Robert Altman's first British feature. Fittingly, the Americana portrait painter of “Nashville” and “Kansas City” has created an elegant, awfully English affair--an atmospheric country-house whodunit with a stellar cast and crew from the UK.

   One winter weekend in the early 1930s a disparate group of socialites assembles for a shooting party at the country estate of Sir William McCordle (Michael Gambon) and his snobbish wife Lady Sylvia (Kristin Scott-Thomas). Among the guests are the countess of Trentham (Maggie Smith), resentful of yet financially dependant on Sir William; Freddie Nesbitt (James Wilby), who is seeking business assistance from the host; the popular matinee idol Ivor Novello (Jeremy Northam); and an American movie producer, Morris Weissman (Bob Balaban).

   Suspicion, blackmail and illicit intimacies run riot among the 14-strong party and they extend to the world ‘downstairs'--the servants' quarters where the guests' maids and valets stay during their masters' visit. Already high, tensions escalate when a murder takes place in the house.

   As nuanced and intricate a society portrait as his Los Angeles tapestry “Short Cuts,” Altman's latest feature benefits from the kind of ensemble cast that few modern-day directors can attract. (Woody Allen, Steven Soderbergh and Paul Thomas Anderson also come to mind.) The director follows a quintessentially English cast--including Charles Dance, Clive Owen, Richard E Grant, Stephen Fry and Derek Jacobi--with real flair, his camera effortlessly gliding from the haughty sophistication of the aristocracy upstairs to the frantic subservience beneath. UK screenwriter James Fellowes' superlative script provides plenty of parallels between the two worlds, not least in terms of their inherent snobbery. The cast, of course, delivers the goods, with standout performances coming from Emily Watson and Helen Mirren. The music--as always in Altman's movies--is marvelous and there is some fine cinematography from Andrew Dunn. Starring Maggie Smith, Alan Bates, Derek Jacobi, Helen Mirren, Charles Dance and Jeremy Northam. Directed by Robert Altman. Written by James Fellowes. Produced by Robert Altman, Jane Frazer and David Levy. A USA release. Mystery/Drama. Rated R for some language and brief sexuality. Running time: 136 min