One of the final links between the Edgar Wallace-based German
krimi genre and the Italian
giallo thriller, this creepy mystery stars
Fabio Testi as a college professor who sleeps with his students and is blamed when a string of murders occurs.
Joachim Fuchsberger, as usual, is the police inspector trying to solve the killings; Camille Keaton,
Buster Keaton's grand-niece and later the star of Meir Zarchi's
I Spit on Your Grave (1980) has a supporting role; cameraman Aristide Massaccesi, later infamous as gore director "
Joe D'Amato," turns up as a cop. Massimo Dallamano's direction is assured. This first-rate thriller was based on Wallace's Secret of the Green Pin. ~ Robert Firsching, All Movie Guide