The fourth in the Rathbone-Bruce series (and second in the 1940s adventures from Universal) finds Holmes and Watson trying to keep a new-fangled bomb site out of the hands of the Nazis. It premiered in February 1943.
This one begins with a bit from "The Empty House," featuring Rathbone in disguise as a German bookseller, and employs the code from "The Dancing Men." Professor Moriarty is on hand, too (he sides with the Nazis, of course), played this time by Lionel Atwill.
Holmes's best line: "I must confess I shied at the thought of disemboweling a complete set of Charles Dickens."
And Moriarty delivers the zinger: "The needle to the last, eh, Holmes?"