A murder at a country house centres around the whereabouts of a horde of stolen diamonds and the unmasking of people who are not as they at first seem.
All 12 jury members who sent an innocent man to the gallows are gathered together for a demonstration of how convictions can be made on circumstantial evidence.
To win the heart of a rather simple minded young man who doesn't seem to care much for women, a young foreign lady takes a job as the chambermaid to the man's sister in law.
A young woman uses her body and her sexuality to help her climb the social ladder, but soon begins to wonder if her new status will ever bring her happiness.