The movie is kind of a murder mystery with not much action rather more a suspense film. Although the story telling is slow the movie has a lot of fan following accumulated during the years and has become a fan favorite for many.
The always excellent well written and documented Spanish blog La abadía de Berzano (El rincón de los cinefagos más desprejuiciados) written mostly by José Luis Salvador Estébenez, Jesús Palop and Fernando Rodríguez were able to catch an interview with Spanish cult director Jorge Grau during his stay at the "X Festival de cine fantástico y de terror de Estepona" last september 2009.
The interviewer was Jesús Palop. He was able to let Jorge Grau talk about his life in the movies, the movies he directed and the stars he worked with. He also talked about his impression of Marisa Mell when they first met each other and how she came to be selected for her role in the movie they made together.
With passing years the creative people who have worked during the Eurocult years in the 60's and 70's are dwindling at a rapid speed. Although there is a lot of material available about the life and work of the stars, directors and producers it is always good to hear the behind the scenes stories from those people directly involved in the creative process during those years. This kind of interview should be done more often now that there is still time as a keep. In 10 or 15 years it is too late. Therefore this interview is a great entry and gives a clear picture of who Jorge Grau is and what his motives were for making the movies that he has done.
You can read the excellent interview here.