Ageing intelligence man Scudder (John Mills) has a fight on his hands - a fight to convince his superiors that there is a dire threat to the British nation imminent. He does not have any concrete proof, and this goes against him when he contacts two officials who humour him by saying that there may well be a Prussian plot against the country designed to sabotage the Navy, but without any further information there's not much they can do, though they will look into it. Alas, that assertion comes too late, for soon those two officials have been assassinated, and Scudder is on the run...
Luckily, the safe haven he opts for is the apartment of an engineer who lives in the same building as Scudder, none other than Richard Hannay (Robert Powell), who would have been best known to audiences of the day not for this film but for a certain classic work from Alfred Hitchcock's British years back in the thirties, then played by Robert Donat. There are still those who refuse to accept anyone else in the role as the definitive Hannay, but Powell made a pretty good try at it in a film that was at once a purely Boys' Own adventure yet also a slightly self-conscious send up of all that type of vintage entertainment.
Many took this at face value, and it did come across as far more straightforward than another Hitchcock remake, The Lady Vanishes of around the same time, but there were strong hints in Powell's performance of a cross between "Don't you know who I am?" and playing the Englishness to the hilt, to the extent that he was aiming for laughs in his Hannay, and not all of them indulgent of the character's stiff upper lipped gentleman's outlook. He certainly came across as having more fun with this as almost anyone else in the film, and little wonder as it was largely his show all the way once Mills had been disposed of in an early on plot twist that sees Hannay left to alert the authorities.
A tricky thing to do when those authorities believe him to be a spy himself, and as if that were not bad enough he also has to contend with the three actual Prussian agents gearing up for war by attempting to weaken the United Kingdom's defences. The trouble with that aspect is that this being set in 1914, the most satisfying outcome would be for Hannay to prevent the First World War from ever happening in the first place, but as we know this is impossible then the best he can do is hold it off for a while before the inevitable occurs. Takes the shine off his heroics, that. Fortunately Powell went above and beyond the call of duty in his performance as well as what he was acting out in the fiction.
This included pulling the emergency chain on a steam train - nostalgists for such trappings were well served here - and climbing from a bridge to escape as all the while those agents were hot on his heels, not to mention the police who think he was responsible for those assassinations. This did not stick to the storyline of the Hitchcock version, so was sufficiently different that close comparisons were not necessary, notably in the way that there was only one woman (Disney heroine Karen Dotrice, all grown up) present with much to do, and that was get saved at the end: this was very much the manly men's yarn all the way. The biggest alteration was the finale dreamt up for Hannay to hang off the face of Big Ben, which some saw as a hark back to the similar ending to the Will Hay comedy My Learned Friend, with to be honest the same amount of hilarity, though unintentional in this case. Although it did lead to Not the Nine O'Clock News using the footage for their News at Ten spoof, so it wasn't all bad - like this film, an amusing romp all the way. Music by Ed Welch.