Karl Anton Verloc and his wife own a small cinema in a quiet London suburb where they live seemingly happily. But Mrs. Verloc does not know that her husband has a secret that will affect their relationship and threaten her teenage brother's life.

Sylvia Sidneyas Mrs. Verloc
Oskar Homolkaas Karl Verloc - Her Husband
Desmond Testeras Stevie - Her Young Brother
John Loderas Ted
Joyce Barbouras Renee
Matthew Boultonas Superintendent Talbot
S. J. Warmingtonas Hollingshead
William Dewhurstas The Professor
Clare Greetas Mrs. Jones (uncredited)
Aubrey Matheras Greengrocer (uncredited)