Sherlock Holmes (1954)

The Case of the Perfect Husband (1x27)

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Russell Partridge announces to his wife Janet one day that he is in fact a killer who has murdered his six previous wives, and notifies her that she has one day to live and get her affairs in order before he murders her, too. Janet can get no one to believe her tale, except Holmes and Watson, who must devise a plan to trap the killer before Janet's time runs out.