The 39 Steps occupies an odd place within Hitchcock's more celebrated British-period films. Although an earlier effort than, say, The Lady Vanishes, it arguably offers a more balanced approach to the blend of comedy and mystery for which he would continue to show an affinity. The blend of elements that would later be developed further with North By Northwest are also on prominent display, making The 39 Steps feel, in many respects, like the first fully-realized Hitchcock film.
Donat and Carroll, however, are certainly the glue that holds the picture together. In lesser hands the roles could simply become slapstick at times, and one-dimensional at others. But each delivers both impassioned and intelligent performances, giving a more realistic edge (within the unrealistic bounds of the story, of course) to their relationship. It's easy to see how they would both be viewed almost as templates for later Hitchcock leading men and women.
It's hard not to be a little disappointed with the video transfer here. It's simply not as strong as some of the other black and white films from this period that Criterion have released on Blu-ray, and especially in comparison with The Lady Vanishes. Although some of the softness in the image is no doubt due to the original master, there's also a much more subdued tonal range on display here. And while not a huge issue, there are some not infrequent instances of debris on the print, as well as image flicker. It's obvious that this has been restored and stabilized over previous prints in circulation, but for whatever reason it does lack some of the crispness and depth of other recent releases.
The LPCM 1.0 audio track is certainly adequate during its mostly dialogue-driven scenes. Characters are balanced and clarity is good. Things aren't quite as strong during some of the larger crowd sequences, such as the opening theater shots, as well as later during the Assembly Hall scenes. Music cues are also tinny in comparison. However, with the period of the picture and sonics of the time, it's certainly not weak either, and obvious restoration and balance adjustments have been made.
The commentary track for this release is provided by Hitchcock scholar Marian Keane. While often illuminating, I have a hard time believing that Hitchcock himself obsessed over as much minutiae in the film as she dissects. Some interesting content, but also very over-analyzed at points. "Hitchcock: The Early Years" (HD, 24;07) is a brief documentary episode covering Hitchcock's pre-Hollywood period. "The Borders of the Possible" (HD, 23:59) is an audio essay by Hitchcock scholar Leonard leff, accompanied by stills and excerpts from the film.