20 years ago, a Scotswoman was accused of an ax murder and let off with the ignominious Scottish verdict of Not Proven. She changes her name and lives down her past, but when her son becomes engaged, his fiancée's godfather spots the mother and recognizes her. In his efforts to trap her, and hers not to be trapped trouble arises.

The Lockwoods are patronising toward their former neighbours, the Hunters, who are now living in the poorer district in town. The Hunters are saved from despair from the help of a young junk dealer named Oliver Read, who teaches the Lockwoods a lesson in humanity.

A Czech scientist escapes from Prague with the aid of an American industrialist, who wants to hire him for his personal benefit. The scientist is followed by a former student, now a fanatic Communist, who insists that the scientist must return to his own country to work for the People's Republic. The scientist must decide whether to return or abandon his countrymen and accept personal freedom in America.