Hitchcock's adaptation of John Buchan's novel is an unsurpassed espionage classic and all in a breathtaking 89 minutes.
A visit to a London Music Hall catapults Richard Hanney into a maelstrom of danger when a European woman who asks him to protect her for the night reveals herself as an undercover agent on the trail of a spy who's about to smuggle British military secrets abroad.
She is murdered as Hanney sleeps and he escapes from both her killers and the police to Scotland where she had traced the culprit.
He eventually gains an ally in unwilling travel companion Pamela and together they discover the secret of The 39 Steps.
An entertaining classic that glitters with wit, Hitchcock surrounds hero Robert Donat with a wonderful supporting cast of scene-stealing cameos, in particular a luminous Peggy Ashcroft as a Crofter's lonely wife and Frederick Piper as a helpful London milkman.
Shelf or charity shop? A shelf to itself!