Golden Age of Radio programs survive. During the 1940s, Basil Rathbone and Nigel Bruce, famous for playing Sherlock Holmes and Dr. Watson in films, repeated their characterizations on radio on "The New Adventures of Sherlock Holmes", which featured both original stories and episodes directly adapted from Arthur Conan Doyle's stories. None of the episodes in which Rathbone and Bruce starred on the radio program were filmed with the two actors as Holmes and Watson, so radio became the only medium in which audiences were able to experience Rathbone and Bruce appearing in some of the more famous Holmes stories, such as "The Speckled Band".
Sherlock Holmes and the Secret Weapon of a Swiss scientist by their nemesis Professor Moriarty, to steal a new bomb sight and sell it to Nazi Germany. Sherlock Holmes and Dr. John Watson have to crack a secret code in order to save the country. The film is one of four films in the series which are in the public domain. Sherlock Holmes (Basil Rathbone) pretends to be a Nazi spy to aid scientist Dr. Franz Tobel (William Post Jr.) and his new invention, a bombsight, in escaping a Gestapo trap in Switzerland. Holmes and Franz fly to London, where Holmes places him under the protection