The Nazis stood no chance once they knew they were up against the Allies' own secret weapon - Sherlock Holmes and Dr Watson. This modernised, morale-boosting story draws only a fraction of the plot from Sir Arthur Conan Doyle's source story The Dancing Men, as Holmes and Watson search for a unique bombsight that could determine the outcome of the Second World War. Basil Rathbone and Nigel Bruce give their customary performances as Baker Street's finest, while Lionel Atwill is believably malevolent as baleful baddie Moriarty. The film was the first in the series to be directed by Roy William Neill, who must have been doing something right - he went on to make ten more before his death in 1946.

In the midst of World War II, Sherlock Holmes rescues the Swiss inventor of a new bomb-sight from the Gestapo and brings him to England, where he quickly falls into the clutches of the evil Professor Moriarty.