La clef

This is a solid Sherlock Holmes mystery in the Basil Rathbone/Nigel Bruce series, with an interesting story, a good villainess, and a good pace once it gets going. Although, as with many movies in the series, the plot is not found in any of the original Holmes books, a number of the story elements were drawn or adapted from various Doyle stories. A number of times Watson also makes reference to one of the 'canonical' cases.

The setup is good, and it produces some interesting possibilities. Holmes must not only figure out a peculiar puzzle involving music boxes, but must do so in a race with a criminal gang that is trying to accomplish the same thing. Patricia Morison makes an elegant adversary for Holmes, and Rathbone and Bruce work well together as always.

Although these later movies in the series do not hold closely to the Victorian atmosphere of the originals, most of them are pretty good in their own right, and while this one mostly follows the usual formula, it is an enjoyable entry in the series.