Sherlock Holmes in Washington (1943)

A British courier is carrying top secret papers that he had put onto microfilm and inserted into a matchbook; realising he is being pursued by Nazi agents, he drops the matches into a handbag of the socialite Nancy Partridge, a fellow passenger. He is subsequently kidnapped and killed and Holmes is instructed to find his killers and the missing document. On his arrival in Washington, Holmes soon realises that Partridge has the document. The Nazi agents, led by William Easter, have also come to the same conclusion and kidnapped her. Holmes tracks her down to an antique shop and meets the owner, whom he recognises as a German agent from the First World War. Holmes, Watson and the police subsequently round up Easter and the gang, and obtain the microfilmed documents.