The 39 Steps (1935)

It seems odd to think of this as an "early" Hitchcock film, since the director already had well over a dozen films (including a couple of minor classics) under his belt by the time he made this one, but it is a significant prototype for his later work that looks forward to themes, plot devices and imagery he would return to again throughout his career. Even with its excellent script, and fine performances by Robert Donat and Madeleine Carroll, it's really the little moments, the subtle but effective touches that Hitchcock brings to the material, that make this one hold up so well. It's certainly one of his most formally inventive works, representing perhaps the moment when Hitchcock's use of sound caught up with his mastery of the image to create his first wholly-realized masterpiece in the sound film medium.

Two moments in particular stand out: the moment when the maid discovers the body of a murdered woman, and turns to the camera with her mouth wide open in horror -- but instead of a scream, we hear the piercing whistle of the train in the shot that immediately follows; and the moment when the pious but hypocritical crofter, discovering that his wife has given away his best coat to the fugitive, begins to beat her mercilessly (off-screen) before cutting away to the sounds of hearty laughter from Donat and the local constable as they inspect a conveniently-placed hymn book, left in the front pocket of the crofter's coat, that has stopped a bullet from hitting Donat's heart.