Ditte is born out of wedlock and lives as a young girl with her old beloved grandmother. As an illegitimate child she is teased in school and more than anything in the world she wants a father. When steady - utterly reliable - herring dealer Lars Petter shows up and tells her that he is marrying Ditte's mother, the little girl is very happy. Now Ditte must take care of three new sisters and brothers but gets nothing but complaints from her ungrateful, selfish mother. But the little girl finds consolation and support in both her sisters and brothers and Lars Petter.

1950 film

A woman is found strangled in her shop. Shortly after, another murder is committed. Perhaps the most terrifying is that the both girls' name is Sonja. The police is convinced it's the same killer and at each scene is heard a woman singing the same song. A song which is soon dubbed the 'murder melody.'