Jack Haley (Wizard of Oz's Tin Man) and Bela Lugosi star in this horror-suspense-comedy. Although calling it horror is like calling Pauly Shore comedy.
A man dies and leaves a very strange will: if his body is buried underground, the order of the inheritances will be reversed so the person with the smallest share receives the largest and so on. Jack Haley shows up as an insurance salesman, but ends up becoming a detective to see who is trying to steal the body and bury it prematurely. Since no one knows what inheritance they're getting, it could be anyone.
Highlight of the movie is by far Bela Lugosi as the butler. He tries numerous times to serve the guests coffee which may or may not be laced with rat poison. (The ambiguity is seemingly cleared up at the end of the film, though I cannot say even I know for sure.) Other commentators have said the film was shot in poor lighting. They're right, but I didn't really have a problem with it. I never was confused about what was happening or where anyone was on the screen. And filming this movie in color probably (though who can say for sure?) would have detracted from its character.
A problem I did have - not related to the lighting - was trying to figure out who everyone was. Maybe I was not paying attention or maybe the plot is weak, but many characters don't have memorable names or associations with each other. This left me confused about who was who at certain key moments. I'm still not clear on who the actual villain is (although a second viewing would probably clear this up).
I laughed, I was suspended, and I laughed some more. Really great film by the standards of the time and worth watching today.