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'.
as Odette Margot / Sonja
as Max Stenberg
as Louis Valdini
as Mrs. Baunsø
as Theatre director Perm
as Assistant Detective Baunsø
as Flora Kristiansen
as Sonja Bohman
as Boarding House Host
as Markussen
as Sonja Neie
as Lise Rasmussen