Sherlock Holmes and the Secret Weapon (1942)

This time our daring duo rescue an innovative Swiss scientist who has developed a game-changing bomb sight that could help give the allies victory. He is brought swiftly to London whereupon he dismantles his apparatus and gives it to four accomplished scientists to keep safe (I suspect, with hindsight, they may have politely declined the honour!). Anyway, he is kidnapped and Holmes and Watson now have to race against their nemesis, Professor Moriarty (Lionel Atwill), to track down the scientist and his kit. A touch preposterous, really - and perhaps just ten minutes too long but still good fun.