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.
Richard Hanney has a rude awakening when a glamorous female spy falls into his bed - with a knife in her back. Having a bit of trouble explaining it all to Scotland Yard, he heads for the hills of Scotland to try to clear his name by locating the spy ring known as The 39 Steps.
When a woman is convicted of murder, one of the jurors selected to serve on the murder-trial jury believes the accused, an aspiring actress, is innocent of the crime and takes it upon himself to apprehend the real killer.
