The Conversation (1974)

Gene Hackman's a surveillance guy and he listens in on what's going on in a park. Then he gets tangled up in some bad-news conspiracy and has to run around and hide. Ultimately something happens in an empty office. I think a beautiful woman is imperiled, maybe even in a particularly perilous way, but Gene Hackman's plan ends up working out perfectly. Mainly I picture our hero at a window with a microphone gun, but I think that's just because that was the DVD cover art.

Seriously? This I don't remember at all.