Sherlock Holmes and the Voice of Terror (1942)
source: https://www.youtube.com/watch?v=mb5F-DB7m5g This video transfer is of excellent quality (no colorization horror, colorization was the precursor of AI slop IMO) although it's not perfect, the uploader puts their marks on the presentation, briefly but persistently :( https://en.wikipedia.org/wiki/Sherlock_Holmes_and_the_Voice_of_Terror Holmes enlists his contacts in the London underworld of 1942 to fight Nazi sabotage and the "voice of terror" who gloats after every successful 3rd column attack on England. But Holmes has a 'scope and the ability to glean whether a broadcast is live or recorded just by doing some plots: Holmes also has an ingenious light cane: That guy thinks of everything ! But for me the definitive fictional London detective during WWII would have to be Michael Kitchen of Foyle's War along with his "Watson", Anthony Howell as Sgt. Milner and Honeysuckle Weeks as his driver, Sam. https://en.wikipedia.org/wiki/Foyle's_War ...