Obsessed

Edwina Black is a sadistic, mean woman who rules her household with cruel force. Both her husband Gregory and her young companion, Elizabeth, suffer from her bitter temperament. However, Elizabeth stays because of her affection for Gregory. The only other member of the household is Ellen, the housekeeper, a malicious gossip who is devoted to her mistress. At every opportunity she tries to insinuate that Gregory and Elizabeth are having an affair. When Edwina is suddenly taken ill and dies, the police perform a post-mortem and discover that she died of arsenic poisoning. All three members of the household become suspects.