Argento's third installment in the "Animal Trilogy" is one of the first to break in to the 90s on the Giallo Score, and for good reason. Flies is a perfect hybrid of the style and mood heavy Bird with the Crystal Plumage and the more straightforward and plot-driven Cat 'o Nine Tails.

Argento hits his stride with this film, which is often overlooked due to it being overshadowed by (arguably) the genre's best film, Deep Red, as well as its lack of availability on home video. With two successful genre films behind him, you can already start to see Argento pushing the boundaries of the Giallo format here. A practice that would continue in Deep Red.

Gialli seem more authentic when there is a high level of psychological trauma that contributes to the killer's motive, and Four Flies is no slouch in that department. Like Bird (and again in Deep Red), the killer suffers significant psychological trauma early in life which, after lying dormant for many years, resurfaces as catalyst for murder.

In addition to motive, all the other genre staples are well accounted for, including an enjoyable Morricone soundtrack and impressive cinematography. And in the end, Nina's slow motion crash and beheading is one of the best Giallo endings ever constructed.

But unfortunately the film falls short of a perfect score for two main reasons:

1. It seems that Argento threw out his black gloves after Bird.
   
   
2. There's never a point in Flies where the characters let their guards down because the killer appears to have been apprehended. In fact, the scene with Roberto hunkered down in his apartment until the final revelation shows how tense he is.

Perfect score aside. Four Flies is a unique film that deserves multiple viewings to fully appreciate its effectiveness.