Sherlock Holmes (Basil Rathbone) smuggles a Swiss inventor of a new bombsight into England and out of Nazi hands. But when the inventor is kidnapped right from under the nose of Scotland Yard, Holmes discovers it's not just the Nazis he has to contend with but his old nemesis Professor Moriarty (Lionel Atwill) as well.

The second in Universal's highly enjoyable Sherlock Holmes series is also the first directed by Roy William Neill, who would direct every Universal Holmes film after this. This is also the first appearance of Inspector Lestrade (Dennis Hoey), a pleasant addition to the series. Rathbone and Nigel Bruce are excellent, as usual. Rathbone gets to dress up in a few disguises, which are fun. He's still sporting that silly haircut from Voice of Terror. Lionel Atwill is a good Moriarty. Not the series' best but still very good. Any movie that features Basil Rathbone vs Lionel Atwill is one where you will be entertained.

For some reason, as with other WWII Holmes movies, a lot of reviewers seem to really hate the idea of Sherlock Holmes fighting against the Nazis or for England. They claim Holmes was never intended for "propaganda" and that he should be left to simple detective stories. Someone should have told Sir Arthur Conan Doyle that when he wrote "His Last Bow," a WWI-era story which saw Holmes helping his country catch German spies.