Sherlock Holmes and the Secret Weapon (1943)

Here Holmes battles arch-enemy Dr Moriarty for the control of the discovery of scientist Tobel, some sort of super-efficient bomb that must not fall into the hands of the nazis. That's right, the nazis. Moriatti has been resurrected (when did he first die?) to allow for a very patriotic, all-is-good-for-England Sherlock Holmes, made during the war, and with a final very patriotic appeal ("this land...England", apparently lines from Shakespeare's Richard II). Moriarty however dies at the end (by falling into his own trap deep into the London sewers).
Holmes plays a lot on disguise here: he starts as a fake German-sounding bookseller to fool two nazi agents, dresses up later as some East-end sailor in London in search of Moriattii, and finally as one of the scientists that Moriatti is trying to capture. Another typical Sherlock Holmes bit in this is the code-deciphering session (one of the two moments when good old reliable Dr. Watson seems at least partly awake, even though he does not crack the code but is a foil for Holmes' more incisive acumen), a process complicated enough to alllow for more delays and more twists in the plot (three scientists are killed during that time). Holmes also escapes death by a hair not just once but twice (once the chest-barrel where he is a prisoner is intercepted by a surprisingly alert Watson, the other time when Moriarty applies the strategem Holmes has himself devised to kill him -- to draw all of his blood out thanks to a needle, "back to the needle, then, he Holmes?", a self-conscious reference to Holmes' drug addiction). As disguises and dramatic escapes suggests, this Sherlock installment is a bit thin on substance, and a bit heavy on theatricals. The substance is of course provided very clearly and explicitly by the patriotic context (England is at war!), and does not allow for any sort of ambiguous treatment as good characters are very good and patriotic, and bad characters have no appeal left in their pro-German positioning -- so that the chase is all that remains to move the narrative along. The good characters are known, the evil ones too -- only the manner of their end is in doubt. Only the situations will move us --and then they have to be exaggerated to do so, a "take-no-prisoner" approach to story-telling that reminds one of serials once the characters have existed for some four episodes (as is the case here, I believe, for Basil Rathbone as Sherlock Holmes: this is the 4th Rathbone-Holmes of the war years, but the first of eleven Rathbone-Holmes-William Neill that will last until 1946).
Thus near-death misses might allow for some questioning of audience's expectations, even if for a very short moment. Were we wrong and is Holmes really done for at this point ? He never really is because of the help he receives from a lot of people. It seems here that half of London's population is made up of police officers (Scotland Yard) or of police informers -- that there is no room for anyone not explicitly connected to the narrative. The strategy of not playing for keeps, of overcharging the narrative with dramatic developments because the basic plot has been reduced to such simple and stereotypical elements leads also here to the near-complete evacuation of any non-plot related character and event. Open up the narrative a bit, allow for some random movement, let Holmes and Watson operate in a more real London (and not just a couple of backstage streets), and the film simply crumbles: either Holmes dies, or Tobel would not be allowed to pursue his experiment alone and government protection would simply snuf all sense of suspense out of the film. In other words, because the film must follow a course of intense theatricals to function, it must also do away with anything that is not artificial.
But then this logic is the whole point of the fun here: it is about arranging plot elements into a coherent and logical thread. For instance, once Holmes has managed to photograph the coded letter left by Tobel, what more could delay a happy resolution ? The inversion of the last writing is the answer. And why are we not surprise that Holmes knows everything, including how to reveal letters not written on a paper, by their chemical reaction? Because of backstory, that bit of continuity which every Conan Doyle fan knows. This episode in the adventures of Sherlock Rathbone thus functions largely as self-reference ot its own metatext -- and the beauty is that even a Doyle ignoramus like me can enjoy this for what it is, a crisp logical construction of plot elements.