That's a surprisingly harsh plot for a movie from this era and the fact [spoiler] that they really showed the explosion and a young boy getting killed [/spoiler] surprised me. Although it is rooted in the realm of spies, terrorism was something not known at the times, it bears a striking resemblence with events happening today. Those old movies are sometimes really worth watching.

I think I find Hitchcock's early British work to be mostly dull, although of course you can see the flashes of brilliance that would become his hallmark. Here, it comes most prominently in the [spoiler] bombing sequence that results in the death of a main character. [/spoiler] But the rest of the movie just doesn't add up to much: performances are stilted and awkward, the pacing is off, etc. I haven't read much about this period, but I wonder if he didn't have access to the same technology as he would have had in the States.