Fan Casting Murder by Death (1986)

Five diverse, infamous private eyes, including Sam Diamond , Sidney Wang and Jessica Marbles ,are invited to the mysterious Lionel Twain's castle for a dinner party. There, they are told that Twain plans an unsolvable murder in the house at midnight -- and he will pay $1 million to the one who determines the killer. But when Twain's blind butler, Bensonmum , dies long before the deadline, the stakes go up for the trapped sleuths.