Allowing for the limitations of the time, this espionage thriller, adapted by Charles Bennett from Somerset Maugham's Ashenden stories is worth watching for Hitchcock's already well-developed stylistic flair. There are some typically Hitchcockian bravura touches – a man running the length of a factory floor, an overhead shot of a car pulling away, and so on, not to mention the model trains and the favoured (studio) setting of Switzerland, elements which Hitchcock revisited in 1938 in The Lady Vanishes. The dialogue between stars John Geilgud and Madeleine Carroll is positively Cowardian whilst Peter Lorre plays a hot-tempered skirt-chasing Mexican hit man and Robert Young an American businessman and a rival suitor for Carroll’s hand, typically Hitchcockian playful elements which help to make the film reasonably diverting in parts if not entirely convincing as a whole.
Released a year after Alfred Hitchcock had scored one of his earliest successes with The 39 Steps, which also starred Carroll and was also scripted by Bennett, Secret Agent is the lesser work.