I actually enjoyed this film a good deal more than anything I'd read had given me to expect. I suppose in retrospect it's (very literally!) a schoolboy story of a pre-war Britain where murder is the preserve of dastardly foreign agents, a naval career is the highest pinnacle to which any right-thinking boy can aspire, and even the enemy is honourable -- but then I always enjoyed those tales on their own terms, and the murder-mystery here, while not deep, is skilfully told. The culprit is fairly obvious from an early stage, despite a trailed red herring of truly clumsy proportions, but the focus shifts imperceptibly from 'who' to 'who next?', and there's a real tension in the sunlit afternoon that leads up to the events of the final part of the plot.
Given what is evidently a low budget or a high sensitivity threshold for gore and explosions -- the body count is all off-screen -- this story of murder and espionage adopts a detached and narrowly-focused viewpoint that perhaps inadvertently echoes the observer/telescope motif running through it: scenes are shown at face value, without a guiding detective figure to steer viewers' deductions, the villain declines the obligatory revelation of his true identity, motives and plans, and we learn of the boy Philip's fateful interview only at second-hand and piecemeal after the event, with no more certain knowledge of whose version to trust than the characters themselves. The result -- for me at any rate -- was a surprisingly understated and effective treatment of what is basically an Agatha Christie or W.E.Johns-type story, relying on the classic plot-lever of vital knowledge locked up in the head of one man. The slow-moving and potentially sentimental amnesia-scenes culminate in a genuinely chilling moment of breakthrough; and the 'flag-waver' finale caught this viewer, at least, into an unfeigned lump in the throat. For those with the requisite knowledge, there is also a wide range of naval melodies to be picked out of the sound-track!
I felt the only false note was Philip's sudden change of career plans by the end; not perhaps implausible as a reaction to events, but presented abruptly as a 'fait accompli' rather than as a revelation of self-discovery. This could have been more convincingly handled to achieve the desired outcome.
Otherwise, the film came across as an enjoyable little piece, and an unintended snapshot of its era with its boyish emphasis on honour, duty and service and its carefully non-specific foreign threat -- attractively photographed, with good use of its location, and well-judged touches of comedy and drama bringing to life the secret-agent-by-numbers plot. This is a Boys' Own adventure in the best sense of the term; not up there with "The Four Feathers" or "Beau Geste", but good lively matinée fodder.
