A weekend at the country estate of a nouveau riche baronet and his blue-blooded wife brings together aristocrats, arrivistes, showbiz people and servants. Everyone's class sensibilities and guilty secrets intensify when a dead body is discovered.
With films we recognise as 'Altmanesque' springing from Los Angeles, Marseilles and New Delhi, it's salutary to revel in a classic model by the master of the movie mosaic himself, as he presides over a richly-nuanced screenplay and an ensemble to die for.
While wittily referring to the manor mystery genre, this is no whodunnit, but a multi-layered tragicomedy of manners, motives and relationships within a decaying social order. A Who's Who of British Equity proves wonderfully adroit at the idiosyncratic, improvisational Altman Experience - theatrical knights wielding and polishing the silver, great dames slinging arch glances and saucepans. Upstairs, ungracious tycoon Michael Gambon is bedevilled by in-laws. Downstairs, hostility between housekeeper Helen Mirren and cook Eileen Atkins builds to a moving, revelatory confrontation without impeding butler Alan Bates' regulation of the staff.
Holding their own in this company are Americans Bob Balaban (Altman's partner in the conception and production) as a coolly-received Hollywood producer and Ryan Phillippe, affecting a purposefully dubious accent, as his highly suspicious valet. Jeremy Northam is just divine as matinee idol Ivor Novello, whose presence provokes sniffs from the aristos but excites the housemaids.
The pivotal character is Kelly Macdonald's Mary, the new lady's maid whose quiet labours position her perfectly to observe the misbehaviour and foibles above and below stairs with perception and sympathy. And although Dame Maggie Smith's imperious countess grabs the largest share of memorable lines, everyone has his moment in this inventive and fully-detailed piece. That includes the valet protesting, "I've washed him and I've dressed him, and if he can't find his own way to the drawing room it's not my fault!"
Altman's best movie in years - an astute exploration of British culture that can stand proudly with his satires of American life. Atmospheric, absorbing, amusing and really fun.