In the Black Museum, Scotland Yard's gallery of death, there is a French-English dictionary, a familiar object. But why is it in the Black Museum? It was 1923 and Betty Brown a married woman on holiday in the little French town meets a French man Joule Nash. He declares his love for her and when she goes home to her husband and the pub he runs, Joule Nash follows her there, which proves to be fatal for landlord Alf Brown.