Arthur Tracy and Lilli Palmer star in this 1930's British romantic drama. With his voice faltering due to nerves, celebrated stage performer "The Street Singer" (Tracy) parts company with the theatre and goes to live in a gypsy camp where he meets and falls in love with Susan (Palmer), an attractive young woman who is unaware of his fame.

A young singer meets a man who is the victim of a kidnap plot, and is assumed by the gang to be his girlfriend.

Lots of slogans such as "Be like Dad, Keep Mum" and "Keep it under your Hat" are visible on the walls in various scenes to reinforce the plot of this British wartime movie illustrating how gossipy talk can result in unknowingly giving valuable information to Nazi spies.

In 19th century England, a noted brain surgeon rescues a former student from being hanged on a false conviction for murder, and spirits him away to an ancient, repurposed abbey far in the countryside. There, he connives his pupil into assisting him in mapping the functions of the various parts of the human brain, using living subjects who are under a terrible animation-suspending drug called "black sleep". Subsequently, the student, along with the daughter of one of the subjects, discover that most of these subjects have survived but are being kept in a dungeon-like cellar, in various stages of physical and mental derangement...