In this classic 1943 film directed by Roy William Neill, Sherlock Holmes (Basil Rathbone) and Doctor Watson (Nigel Bruce) must protect a Swiss inventor of an advanced bomb site from falling into German hands. Beginning in Switzerland, and working for the British government, Holmes manages to spirit the bomb-site inventor, Dr. Franz Tobel, out of Switzerland and into England before the gestapo are able to get to him. But back in London, the inventor is not all that he seems. Tobel has devised an immensely accurate bomb site, and while he is willing to make it available to the Allies and protect it from the Nazis, he insists on manufacturing it himself. Soon however, he vanishes and it is left to Homes, assisted by the bumbling Dr. Watson, to decipher a coded message left behind. Holmes soon realizes that he is up against none other than his nemesis, Professor Moriarty.