1944, US, directed by Fritz Lang
When the Siren dispenses advice I find that it's worth following, and thus I watched The Woman in the Window before reading her recent piece on the film's ending; I second her counsel for anyone who would prefer not to find the film's dénouement unknotted before its time (in other words, stop here if you want to enjoy the ending unspoiled).
Although that conclusion has been much discussed across the decades, I'd successfully managed to avoid any knowledge about the outcome until this point, and was drawn into the film's hypnotic rhythm unawares. Although less sweaty than films like The Window or Rear Window -- the window in question here is of a different order, but still, what is it about windows in New York? -- it's very much a classic of the New York summertime, with unexpected occurrences multiplying in the humidity.
The entire film flows from one small decision, wherein Edward G. Robinson, who plays a married college professor -- "Assistant Professor," his character insists at one point -- takes an attractive woman up on her offer of a little conversation. The professor quickly finds that he has bitten off much, much more than he's bargained for but also discovers within himself a surprising seam of ice-cool criminality, all rendered the more ironic since his academic specialty is supposed to be the murderous mind.
The aforementioned ending reveals the entire film, virtually from this crucial moment, to have been a dream in the professor's apparently fevered mind -- if only he'd take off that jacket, perhaps he'd have avoided all of his problems. Retrospectively, the dream framework renders much of the film more logical, particularly the presence of a friend who also happens to be a DA feeding Robinson information on the case, and giving him the sense of an ever-tightening noose. From what I can tell, the framework -- revealed in a beautiful bit of camera trickery in which Robinson's face is framed, silent-movie style, while the room around him is transformed -- was always intended by Lang, rendering the film, in a sense, as the lengthy buildup to a terrific punchline. His delivery is spot on -- the sense of gathering doom is seamlessly constructed, while the apparently inoffensive Robinson's turn toward amorality is one of the film's nicest frissons.