This fine Giallo tells an unusual story in an unusual way, and even though not much happens in the first half of the film, director Tessari manages to grip the viewer's attention from the beginning through stylish directing and really thrilling and creepy moments. In the second half, as the plot thickens and the parts of the puzzle begin to fit into a whole (i.e. as the main character starts to remember more and more of his past), there are also some fairly violent scenes, e.g. as a villain falls over a cliff or beautiful female lead Senta Berger swings a chainsaw. But, most importantly, even though the plot is a quite complicated net of strings that has to be lead together to the climax, the story remains plausible until the end, which isn't always the case in films of this genre.<br /><br />Apart from the convincing performance by Berger, Luc Merenda is also well casted in the title role, as is Umberto Orsini in the main supporting role. Look out for Giallo regular Anita Strindberg in a small but crucial role. The lush sound track is also very cool and adds to the viewing pleasure. The only shame is that, as with too many other Italian films of the 1970s, this memorable Giallo is quite rare and hard to get. Rating: 8 out of 10.