 Originally the film was to have starred Daria Nicolodi (qv), who  was Argentos girlfriend at the time and who also wrote the  screenplay. However, Argento decided to go with a younger actress.  Daria Nicolodi does appear in the film twice: she can be glimpsed in  the films opening sequence that shows Susy walking through the  airport, and she also provides the gravelly voice of Helena Markos.