I have a question

Whereas it is correct that the reason this, and the majority of the other Rathbone/Bruce Holmes movies, take place in a contmporary setting (for the times they were made) was due to budgetary constraints, only the first three 1940's set ones actively mix World War II into their plots.

After 20th Century Fox produced their two, large, period adaptations ("The Hound of the Baskervilles," and, "The Adventures of Sherlock Holmes"), and despite their success, they chose not to make any more due to the cost of producing them in the period setting. With Rathbone and Bruce being extremely popular portraying the characters on radio at the time Universal took over the rights with the plan to make them as a series of B-movies, setting them in the then present day (although they were legally bound to adapt some of Conan-Doyles works which is why some are very loose adaptations) as a means to cut costs and, initailly, to have Holmes going up against the Nazi hordes.

However, the introduction of Roy William Neill as director/producer led to this idea being scrapped as he much preferred Holmes battling more conventional criminals. As such, only, "The Voice of Terror," "The Secret Weapon," and, "Sherlock Holmes in Washington," (to a lesser degree) have any actual plots with Holmes taking on the Nazi's. The others, such as this movie, deal with, "Criminal Masterminds," and the like, and their diabolical plots with the War itself touched on but only as part of their period settings, such as Holmes quoting Churchill on occasion.