A mere wisp of a movie, yet a deeply beguiling one, "The Shooting Party" gains stature from the fact that it includes the last film appearance of James Mason, a great actor who died last year. As the quintessential baronial gent entertaining a dizzy gaggle of guests at his stately country home, Mason is effortlessly authoritative in this film and still, at 75, craggily handsome. How appropriate that the movie is an elegy.

Set on a crisp British weekend late in 1913, the film, based on a novel by Isabel Colegate, and now playing at the K-B Fine Arts and K-B Paris, is hardly coy about its parabolical allegorical aspirations. The characters all but announce -- in fact, they do announce -- that they are the denizens of an era's end, that a curtain is about to fall, that the world will be changed forever, as it is forever being changed forever, and that World War I is just around the corner, waiting to rattle the china.

"I think an age, perhaps even a civilization, is coming to an end," says a guest at dinner, whereupon director Alan Bridges cuts to the fireplace so that a log can sputter in ominous accord. Julian Bond's screenplay is just that bald but, strangely or not, the fact that the characters all seem to know they are pawns in a game of social symbolism doesn't detract from the pungency of that symbolism. It strengthens it.

As orderly and civilized as the Edwardian age whose passage it portrays, "The Shooting Party" is like a particularly tony, thoughtful edition of "Masterpiece Theatre," only much briefer. It successfully conjures a time when even adultery was conducted politely, and it evolves with subtle cumulative strength from what would seem just another ritual savaging of a long-departed aristocracy into a poignant, evocative lament, both funny and tender. Not for nothing does it take place in autumn. It's one of the most autumnal pictures ever made.

It's so autumnal it makes you yearn for summer to pass and the sky to turn gray.

Mason's voice is the first heard in the film. As Sir Randolph Nettleby, achingly comfortable and all too well-to-do, he unapologetically announces that "Life is so extraordinarily pleasant for those of us who are fortunate enough to have been born in the right place." The film follows the events, trivial and traumatic, of the ensuing weekend. The male guests head for the woods and there proceed to divest the skies of pheasant and duck. The women negotiate minor intrigues, wonder aloud why men insist on shooting at things, and even entertain an ambition to "rebel against the world men have made."

Tempestuous Lady Aline (Cheryl Campbell) and her stoical husband Lord Hartlip (Edward Fox) are having a bit of a beastly marriage that has now cast him in the role of cuckold; during an argument in her room, she scowls, "Don't try to be pathetic." The dashing Lionel Stephens (Rupert Frazer) and the wistful Lady Lilburn (Judi Bowker) would be having an affair, Lord knows, except that she is rather married and he is every millimeter a gentleman. They do a lot of plaintive staring into one another's eyes.

John the butler (Daniel Chatto) composes desperate love letters to Violet the maid (Mia Fothergill) out of scraps from discarded ones Lionel wrote to Olivia but never sent. Sir Randolph's wife, Lady Minnie (Dorothy Tutin) listens patiently as Lady Aline outlines her gambling debts and asks for a loan. Further on the periphery are a Hungarian snob (Joris Stuyck), local gamekeeper Tom Harker (Gordon Jackson, long ago Mr. Hudson on "Upstairs, Downstairs") and a wild duck named Alfreda Beetle who makes an untimely disappearance.

As if the assemblage weren't illustrious enough, John Gielgud dotters endearingly about as Cornelius Cardew, an idealistic pamphleteer ("The Rights of Animals") who marches with great indignation onto the grounds and denounces the hunters as murderers. Fortunately this necessitates a confrontation with Sir Randolph. Mason and Gielgud meet there in the field and disarm not only each other, but any even moderately vulnerable witness. The scene transcends the film. When Mason and Gielgud part, the loss of Mason suddenly becomes more real and more cruel. It's as if this moment were Mason's official farewell, and Gielgud's personal tribute.

There won't be good actors in just this vein again, will there? Mason didn't just have stature, he had bearing. Nobody even wants to have bearing anymore. Whether playing Humbert Humbert or Norman Maine or the persecuted rebel of "Odd Man Out," Mason was a fascinatingly haunted figure. His worried sophistication is perfect for Sir Randolph, who seems to have visions of the world in full topple, and who realizes there is no particular defense. In the film's most moving scene, brilliantly sustained by Bridges, Sir Randolph comforts a dying man hit by a stray bullet, even though he's from another, and lower, class.

Too mild to be satire, too mannerly to be ferocious, the film has the warmingly contemplative quality of late-night conversation between the very best of friends. It's not a popcorn movie, it's a sherry movie. Mason's performance elevates "Shooting Party" from diverting to profound. At times it ceases to be a movie and becomes a life achievement award. Mason leaves the screen with dignity. Indeed, one might logically fear that he took the whole idea of dignity with him.