L'Uccello Dalle Piume di Cristallo (The Bird With the Crystal Plumage) (1970) ***

An American in Italy watches what he thinks is a man murderously attacking a woman while trapped helplessly through two sets of glass doors. Later he becomes convinced that what he saw was not as it seemed, and as the only eyewitness finds that the killer is now after him.

Dario Argento's first film as a director reinvents the Hitchcockian suspense film as something altogether darker, more enigmatic and quintessentially Italian, thus setting in stone almost all of the rules and conventions of the Giallo movie.
Perhaps the biggest surprise is that it still works so well as a thriller: the plot is involving and clever and Argento's set pieces retain all their bravura. Ennio Morricone's score adds to the off-kilter mood; the violence, though by no means minimal, is not yet as self-justifying as it would later become in Argento's career. Not the director's flashiest film, but probably his most perfectly conceived.