I saw a movie on TV twice in the early 80s when I was young that I really loved it and would like to see again. I have searched for it by reading classic movie descriptions but cannot find it. I hope you can help. Here is what I can remember. Its in black and white set in an old creepy mansion atop a hill. Its similar to "Clue" in that guests are mysteriously invited to the house by an unknown host. It begins showing some of the guests driving up the unpaved road in the rain to the house. I believe one of the cars gets stuck and they have to walk or someone gives them a lift. I believe they were all great detectives brought together by the host. The host was wanting to challenge the greatest detectives with a mystery. I remember that there is some comedy mixed with the suspense in this movie, and that they are offered a lot a money if they can survive the night as well as guess who the host is. Near the end they are locked in their individual rooms for the night. Each faces separate dooms. In the morning, one or two survivors track down the host to collect their money. There is a long dialogue here where the guests try to guess who the man is as he is wearing a mask. At one point one of the guests dies from being poisoned during the night I believe. At this point he is unmasked but then in a twist ending, the surviving guest takes a second mask off of the host and he is declared the winner and takes the money. As the survivor drives down the road again he comes across another car going up to the house, and it is Sherlock Holmes. Then at the very end, it shows the host take off yet another mask and laugh evilly but not showing his face.
Tags: classic, name, thriller