Mario Bava directs this influential Italian 'giallo' about a killer who lives in the shadows and stalks models, a film that inspired slasher flicks of the 1980s with its innovative camera tricks and an impressive roster of dead bodies. The only clue to the murderer's identity is a diary kept by of one of his fashion victims. But he's determined to keep anyone from actually reading it. Cameron Mitchell, Eva Bartok and Thomas Reiner co-star.