The 39 Steps (1935): 7 Minutes of Aching Extramarital Lust

The 39 Steps gives us a glimpse of adulterous longing.  

Richard Hannay (Robert Donay) has been wrongly blamed for murdering a young woman and must find the real murderer before the police catch up to him.  While fleeing across the countryside, he stops at a farm cottage for a meal and a rest.  The farmer has an unkindly disposition and is wary of strangers, but he is willing to accept the man as a guest for a fee.  

Hannay chats with the farmer's wife, Margaret (Peggy Ashcroft), while she prepares dinner. 

Hannay notices a newspaper with a headline about the police manhunt.  Margaret sees his reaction to the headline.  The two exchange urgent glances.  Margaret has sympathy for her desperate guest and is determined to help him the best that she can.  The farmer can see that something is going on between his wife and the stranger.  This makes him bitterly jealous and causes him to keep a close watch on them.  

He spies on the couple through a kitchen window.

He is so agitated that he is unable to sleep.

Margaret hears a police car coming up the road in the middle of the night.  She awakens Hannay to warn him and help him to escape.

In a 1962 interview, director Alfred Hitchcock admitted to François Truffaut that the shy and quiet Margaret has sexual interest in the handsome and gentlemanly stranger.  We see an undeniable longing and desolation in her expression after Hannay kisses her goodbye.  

The scenes at the cottage are undoubtedly elevated by Ashcroft's sensitive performance.  It is a brief segment of the film, but it leaves a strong impression.  

Peggy Ashcroft is seen by many Shakespeare aficionados as the greatest Juliet of the 20th century.

https://www.amazon.com/Unfaithful-History-Adultery-Anthony-Balducci/dp/B0C8Y1L7KK