What a disappointment this episode was. Having previously praised the mostly accurate authenticity of this series, this one was a total disappointment. The most crass inaccuracy (how on earth did it get past anyone with half a brain?) was showing an alleged Royal Navy Captain, working at the Admiralty no less, wearing a Thin, Military Moustache!!! There were 'No' moustaches in the British Navy. A full beard OR clean-shaven. Heads should roll for that one alone! Others - A 'hush, hush' secret establishment working on a 'secret' weapon without any security at all???? No guards, overt or hidden? Doors open to anyone? Known to be saboteurs operating in the area? The saboteurs themselves, only incompetent youths? A suitcase full of sticks of explosive detonating but not killing 4 people within a few metres??? A proved hostile 'neutral' diplomat known to be organising sabotage and nothing is done??? Oh, dear, oh dear, oh dear. (145 words)