Anecdotes

This was the last Charlie Chan movie produced by 20th Century Fox Studios, because America's entry into World War II in December 1941, shortly after this movie was filmed, made the studio cut back on film productions for the war effort.

The castle interior recycled the still-standing set from the first entry in the Basil Rathbone Sherlock Holmes series, Le chien des Baskerville (1939).

Naming the residents of the isolated castle Manderley is a reference the the mansion in Rebecca (1940).

The exterior of the hotel would later be dressed as the saloon for L'étrange incident (1943).

The thirtieth of forty-seven Charlie Chan movies.