I knew only little about Gosford Park before, only that it had won an Oscar and that one of my favourite actors (Stephen Fry) was in it.
Outwardly it is a murder story, but the plot isnt important at all. What really is interesting are the characters.
There is the newly rich Sir William, who is rightfully hated by everyone. He has invited a couple of people to a hunting party. All these upstairs characters are lonely losers in their own special ways.
There are the downstairs characters: the servants of the house and the valets and maids brought by the guests. Since they dont know each other, they call each other by their masters or mistresses names, thus the valet of, say, Lord Stockbridge becomes Mr. Stockbridge downstairs.
This way it is not very difficult to understand what the movie is about: the downstairs persons are no real persons, they dont have a life of their own, they dont even have names. It is then no wonder that the upstairs inspector (a wonderfully confused Stephen Fry) cannot find a clue to the case, not only does he ignore every idea uttered by the downstairs constable, he also doesnt even interview all servants, because we are not interested in servants, we are interested in people with a real connection to the dead man.
It is left to one of the guests maid to discover the truth, but since she belongs downstairs she doesnt say anything and she is never asked.
The movie is a very clever portrait of the English society of the 30s with all its snobbishness and falsehoods.