Canadian Richard Hannay, residing in London, meets secret agent Annabella Smith immediately following a shots fired incident. She asks to go home with him.
It's melodrama and at times far-fetched and improbable, but the story twists and spins artfully from one high-powered sequence to another while the entertainment holds like steel cable from start to finish.
If you can imagine Anatole France writing a detective story you will have some notion of the artistry that Hitchcock brings to this screen version of John Buchan's novel.
As an artist, Alfred Hitchcock surpassed this early achievement many times in his career, but for sheer entertainment value it still stands in the forefront of his work.
The Thirty-Nine Steps neatly converts its essential implausihility into an asset by stressing the difficulties which confront its hero when he tries to tell outsiders about the predicament he is in.