In November 1932, Sir William McCordle is having a shooting party at his country estate. He is married to the Earl of Carton's eldest daughter, Sylvia. They have one child, a daughter, named Isobel. He has a little dog np-one likes named Pip. They've invited Sylvia's two sisters and their husbands, her Aunt Constance the Countess of Trentham, and a number of other young men (married and unmarried) for the shooting, as well as William's distant cousin, matinee idol Ivor Novello, and his American friend, Charlie Chan producer Maurice Weissman.
Accompanying the upstairs guests are their servants--chauffeurs, valets to dress the men, lady's maids to dress the women. They join the belowstairs staff at Gosford Park, commanded by the fearsome dour Mrs Wilson the housekeeper, Jennings the butler, and Mrs Croft the sour old cook.
We see this world where upstairs and downstairs collide through the eyes of Lady Trentham's new maid, a young Scottish girl named Mary MacEachran. Mary is very young, and utterly inexperienced, and quickly befriends head housemaid Elsie, and Lord Stockbridge's valet, the mysterious Robert Parks. Also in attendance is Weissman's valet, the smarmy yet very pretty Henry Denton, with his bowler hat and wandering accent.
Sir William loves country sports, even though his is awful at them. William as nouveaux riche, and he and his wife cannot actually stand one another. Isobel fancies Lord Rupert, but Rupert is a young son and worried Sir William will think he's only after Isobel's money. Rupert's hanger-on friend Jeremy Blond is using Rupert as his entree into society, and is really just there to get a taste of the high life. Freddie Nesbitt blackmailed Isobel into getting him an invitation, in the hopes that the week-end will result in his getting a job as one of William's bakers. His hopelessly middle class wife Mabel is overawed by the company, and very much a fan. Sylvia's sister Lavinia married a hopeless Naval Commander who adores his wife but is a wreck in business, and William is hoping to get out of the week-end without having to tell Cmdr. Meredith he's pulling out of his investment scheme. Ivor is playing the piano for his supper, and Morris thinks the whole upper crust world is too hilarious for words, and is mining it for research for his next picture, Charlie Chan in London.
Then in the middle of the second night, Sir William is murdered.
Mary alone is in the position of putting all the peieces together--from overheard servants gossip, to a midnight confession sealed with a kiss, to Lady Sylvia recounting the house's history to her sister as if Mary was invisible and a piece of furniture in the corner. And it's up to Mary to decide which secrets to keep or share.
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