Sudden Fear (1952) on Netflix

After an ambitious actor insinuates himself into the life of a wealthy middle-aged playwright and marries her, he plots with his mistress to murder her.

Actor Lester Blaine has all but landed the lead in Myra Hudson's new play when Myra vetoes him because, to her, he doesn't look like a "romantic leading man." On a train from New York to San Francisco, Blaine sets out to prove Myra wrong...by romancing her. Is he sincere, or does he have a dark ulterior motive? The answer brings on a game of cat and mouse; but who's the cat and who's the mouse?

—Rod Crawford <puffinus@u.washington.edu>

The wealthy playwright Myra Hudson is the heiress of a great fortune. However she works and is donating part of her inheritance to foundations. When she watches the rehearsal of her play, she asks the director to replace the lead actor Lester Blaine that she believes is not adequate for the lead role. When she returns home, she meets Blane in the same train and they travel together. They stop in Chicago and soon Myra is seduced by him. They get married and live at Myra's home in San Francisco. Myra summons her lawyer Steve Kearney to change her will and transfer her fortune and properties to her beloved husband. She uses her Dictaphone to record the changes to be done in her will. However Steve will travel with his son Junior Kearney to Sacramento and they leave the room. Then Blaine and Junior's girlfriend Irene Neves, who is his lover, come to the room to plot a scheme to kill Myra so that he will be the heir of her fortune. On the next morning, Myra learns that she has forgotten her Dictaphone on and when she will proceed to dictate her new will, she hears the conversation of her husband with Irene. What will she do now that she knows what are Blaine's real feelings and intention?

—Claudio Carvalho, Rio de Janeiro, Brazil