This film really seemed like two movies: before the train and after the train. Sometimes it's a struggle watching a few of Hitchcock's movies where what we think of as vital information not coming full circle, but I suppose that's the Mcguffin effect. Mainly with this film it's the characters of Charters and Caldicott (Naunton Wayne and Basil Radford) who open the picture with a comedic entrance and then fade off into utter insignificance to the story. Upon doing research Charters and Caldicott was a popular comedic duo at the time, so at the very worst they were used as a gimmick in the beginning of the film, which might make sense because the story does take awhile to pick up speed.
Gilbert (Michael Redgrave) has one of the most unappealing starts to his character and instead of redeeming himself he almost becomes someone else once he's on the train which struck me as confusing. Honestly until the fight with Signor Doppo (Philip Leaver) I was bored with it all. If the Mcguffin is the idea that the details don't matter, why not cut out the whole act 1 because it's pointless and just start right before the train? For a phony mislead? Seems that Hitchcock employed both of these methods masterfully in North by Northwest (getting right to the action) and then Psycho (using the mislead to great effect). Although even in Psycho there is no time wasted: it begins with Marion (Janet Leigh) stealing the money and then fleeing to Bates. Despite the success of this film Hitchcock still has kinks to figure out, but the great moments prove to outweigh the dull. That being said the ending was extremely dull as well, but when the Mcguffin takes away the details that leaves a lack of denouement in Hitchcock's films.
Some of the great moments: the asshole Mr. Todhunter (Cecil Parker) dying. The whole shootout on the train, specifically how it was a bunch of everyday people with guns. The terrifying moment when the poster of Signor Doppo pops up in Iris' (Margaret Lockwood) face. The aesthetic of Miss Froy (May Whitty) being a spy.
Despite it's shortcomings, Hitchcock still accomplishes what he does best—telling a suspenseful, original story.