If you loved Shadow of a Doubt, try The 39 Steps
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Alfred Hitchcock, and they sit in Mystery / Thriller territory. If that's the register that drew you to Shadow of a Doubt, the second film will land in a comparable space — through a different lens.
What The 39 Steps is
London, rain-soaked streets, a scream in the night. A mysterious woman collapses into a stranger's apartment, a knife in her back, a cryptic map in her hand. This is Hitchcock at his most economical.

