Upstairs, the mistress of the house boffs a young valet. Downstairs, a randy aristocrat bangs away at a plump kitchen maid. All the while, the police try to figure out who killed the lord of the manor. Everyone is a suspect.

Set in an English country estate, in 1932, Gosford Park appears to be a murder mystery. But sly-boots director Robert Altman, working from a deft script by Julian Fellowes, knows better. He has spiked the plot with naughty laughs, cast it with acting royalty — mostly British — and let the social satire fall where it may. It's the party of the year. For a shooting weekend at Gosford Park, blustering horn-dog Sir William McCordle (Michael Gambon) and his imperious wife, Lady Sylvia (Kristin Scott Thomas), welcome guests including squabbling relatives and composer, singer and film star Ivor Novello (smoothie Jeremy Northam), the film's only nonfictional character. Lady Sylvia's aunt, the Countess of Trentham (a hilariously larger-than-life Maggie Smith), is aghast ("After you meet a celebrity, there's absolutely nothing to say").

There is nothing like Dame Maggie, who is comic perfection in the film's most delicious role. Watch her roll her eyes as Ivor's Hollywood guest, Morris (Bob Balaban), a producer of Charlie Chan mysteries, refuses to reveal the plot of his latest film to the gathered dinner guests. "But," sniffs the countess, "none of us will ever see it."

Morris has brought along a boy valet, Henry (Ryan Phillippe), whose brogue is pegged as fake by Mary (Kelly Macdonald), Scottish maid to the countess and our guide through this nest of vipers.

The servants wait on the snobs with barely concealed contempt, and since they are played by the gifted likes of Alan Bates, Derek Jacobi, Helen Mirren, Eileen Atkins, Richard E. Grant, Emily Watson and Croupier find Clive Owen, their presence is a constant delight. Ditto the sumptuous and witty production design of Stephen Altman, the director's son. So don't complain if you need a scorecard to keep track of the characters. A second visit to Gosford Park is beneficial and twice the fun.

Don't bother with those who fault Altman for co-opting the class issues raised in Jean Renoir's 1939 classic The Rules of the Game and filtering them through his allegedly misanthropic eye. Not so. Be it McCabe and Mrs. Miller or Short Cuts, Altman invariably stands with the foolish mortals who inhabit his films, not in godly judgment of them. A line from Renoir's film — "Everyone has his reasons" — sums up Altman's work. No misanthrope directed the lovely scene in which the servants, standing outside the drawing room, crane to hear snatches of the tune Novello sings to the distracted guests. Gosford Park abounds in scenes to savor. It's a feast, and one of Altman's best.

“Alison”

On Elvis Costello’s country-tinged ballad, the lyric does not get too sentimental in recalling an ex who had since been with one of the singer's "little friends" and is now married. Some believe the song is about murder, due to lines like “Sometimes I wish that I could stop you from talking,” "Somebody better put out the big light" and, of course, "My aim is true,” which became the title of Costello's debut album. In 2002, Costello told Rolling Stone, “It isn’t [about murder]. It’s about disappointing somebody. It’s a thin line between love and hate, as the Persuaders sang.”