Blackmailed (1951)

Mrs. Christopher (Fay Compton), a kindly volunteer worker at a large hospital, does a favor for a patient by delivering a sum of money to Mr. Sine (James Robertson Justice). After she discovers he is a blackmailer, she threatens to expose him, and a struggle ensues in which she kills him. Her willingness to take the law into her own hands has a disastrous effect on former victims of the blackmailer.