Forgettable, humdrum cheapie which, although I only saw it a few hours go, is already quite difficult to summarise coherently. Brown of special branch (Terence Morgan) must catch an unknown 'master-spy' before they are able to smuggle something incredibly vital out of the country. This leads him to a power station where an assortment of brilliant scientists work, one of whom Brown concludes must be the spy. At some point there is a security alert, causing people to rush about in a panic because someone, or something, has left the building. Who? What? Why? I don't know, because it isn't mentioned again, and they carry on looking for the thing that mustn't leave the country. Later, hundreds of police cars chase a car through the countryside, and Brown orders a light aircraft to follow suit, though the cars get there just as quickly. The quarry is caught at a barn, but he's not the villain, he's simply a Polish resistance fighter who hasn't been told that the war is over. But then a soldier appears with a metal suitcase, and tests show that its contents are radioactive. So, is this the thing that mustn't leave the country? I don't know - if it is, why is it being delivered to a harmless Polish freedom fighter? Pass. Anyway, it all ends up back at the power station, with (I think) the same metal suitcase and, when Brown engineers a fake news report, the real master spy, a wizened old boffin of about seventy, panics, and proceeds to outrun the entire police force around the grounds of the plant, before going back inside and shooting himself.
I forgot to mention that Brown, inexplicably, has a manservant, who insists on behaving suspiciously so that a few reels can be wasted on chasing him around, and also an unfeasibly long-suffering girlfriend whose sole purpose is to generate an overdone joke about Brown constantly standing her up on dates (he only comes home once in a while to say that he's got to go out again). To pass the time she cooks the slowest slow-cook pie in history, which, if she has any sense, she has laced with rat poison. Meanwhile, in the background, is Andre Morell, on death row, trying to bargain his way out of being hanged, by refusing to reveal the name of the spy, and by boring his guards to death with endless games of cribbage.
If anyone can explain the plot of this ragbag of events, please do so.