Work number one by Dario Argento, this movie is also referred to as the original matrix to the Italian Giallo Movies. Check out the reason why. Excellent plot, good acting, sensational atmosphere, black gloves, hats and raincoats, knives, razors, screaming good-looking girls, sex traumas, violence, gore, and that flash, burnt in the protagonist's memory, which is the key to the solution (and what a solution!) to the entire plot. This is enough to recommend you the purchase of a DVD which, unfortunately, is quite disappointing. The video format is partly disturbed, the audio is unbelievably in mono and no extras are available rather than the theatrical trailer and (good choice) the original soundtrack by Ennio Morricone. But we're talking about a masterpiece, and I suggest this purchase anyway.